The glue vs. nail question

trofeo

True Grumbler
Joined
May 25, 2005
Posts
71
Loc
Seattle, WA
Here's a curious question:
I have a framing friend who says that you don't need glue to hold frames together, and another friend who says you don't need nails or v-nails.. just glue.
I have always thought that everything, (nails, glue, and even paper backing), hep hold the frame together..

What is the right answer?

It worries me that my friend isn't using glue because it seems important..
What do you think?
 
It has always been my understanding that nails hold the frame together while the glue is setting up, and then, even with today's stonger wood glues which will rip wood apart rather than the join, in case of future jarring events, like the dropping or falling of the frame, then the nails hold the frame together sufficiently to prevent damage to the enclosed artwork.
 
I've always understood that they work together to hold the frame together, like Mar said. And I've always used both. Unless I forget. And then I'm sorry I forgot later, when the customer brings it back after it fell apart. Embarrassing.
 
If I had only had one option I'd go for the glue by itself rather than nails alone.

But the only time I do that is for joining miniature frames that are too tiny for my vise, and then most times I still use nails to join the first two corners (while they still fit in the vise).
 
Could there be a parallel here with concrete and steel reinforcement?
Perhaps two things together work together to give more strength than one on it's own.
There might be situations where just glue is OK and others where just nails might be OK, but for maximum strength, both should be used. I use both so that I reduce the possibility of needing to do the job over again.
 
On a smoothly mitred corner such as that yeilded from a Guillotine I suspect that the strength of adhesive is moot as it may often have no surface into which it can gain any "tooth" (because the cut is so smooth).

A glue only corner should have some form of design element that encourages better support from adhesives such as a biscuit or dowel rod.

Nails are prone to rust and therefore cannot be relied on entirely either, the combination of both is certainly advisable. Glue only, or nails only is asking for trouble and would perhaps indicate ignorance or indifference.
 
Originally posted by Lance E:
On a smoothly mitred corner such as that yeilded from a Guillotine I suspect that the strength of adhesive is moot as it may often have no surface into which it can gain any "tooth" (because the cut is so smooth).
Even on a chopper cut where the cells are mashed over and you have a shiny cut, as long as the knives aren't so dull that they are pushing the wood or head away so that the cut is not in a single plane, the glue joint is very strong. Glue is a chemical bond, not mechanical, so the "tooth" only increases surface area and then you are on a technical journey of calculating adhesive versus cohesive strength as well as the fill characteristics of the glue in question.

On a chopper cut with sharp knives you can actually look "into" the end of the stick because it's cut so cleanly. It looks dull and feels a bit rough too.

But back to the question, absolutely use both in most circumstances.
 
I realize the that Jerome's Biscut suggestion is avery good one,but in the abscence of a Biscut machine,I also agree completely with davids comments about nothing sealing off the pours of a wood moulding ,even sanding. I'd wonder if theses two comments on the Miter gap thread might add some input especially if Jim or some other FACTS expert would care to annalyzre them and comment firther:


Jim Miller
SGF Supreme Grumbler
Member # 697

posted 05-02-2006 12:14 PM
--------------------------------------------------------------------------------
Here's another thought:

Each piece of steel inserted by your underpinner acts as a wedge. The more fasteners you insert, the more the corner will tend to tighten on the inside and separate at the outside, even if your miters are perfect. So, use enough fasteners to hold the corner together, and no more than necessary.

--------------------
Jim Miller

--------------------------------------------------------------------------------
Posts: 3171 | From: Pickerington, a Columbus suburb | Registered: May 2000 | IP: Logged |

BUDDY
SGF Supreme Grumbler
Member # 13

posted 05-02-2006 12:41 PM
--------------------------------------------------------------------------------
Jim that suggestion you just gave does that amount to the same advise we are always told that the V- nails and/or brads are just a temporary fastener to hold the corner together until the Glue dries. That is to say that the strenght of the brad or v-nail isn't intended to hold the corner to a secure fit ,even if they do squeeze ? No matter how many you use or where you place them. In fact as you sound to me to be saying sometimes it can work just the other way around.

Also It seems to me that if the two mitered corners don't meet exactly even when placed together ,why would you want to force them. Doesn't that seem to say that one or both were cut wrong to start with?

But then I need a lot of fitting instruction myself.
And Tom your suggestion has been wanted by old framers for a loooong time.It might be a good place to put some of our Framing Myths Threads .LOL


BUDDY
 
I did not specifically suggest any type of joinery. My intent was to inform that a 45° miter joint with only end grain glue surface is probally the weakest joint used in woodworking.
 
It's funny that you asked this this week. I just repaired a framed that was joined only with glue. It was moved and set down a little hard, but not dropped. It, of course, came apart.
The frame shop that did the work is no longer in business, So I did the repair.

I would never send one out without using both glue and nails. It's just not worth the risk of embarressment or even injury.

Jennifer
 
There are those who place corners in vises for 15 to 30 minutes and then insert v nails once the glue joint is strong enough to stay together on its own. In those cases, inserting metal fasteners is really unnecessary and I would argue a bad practice.

The only resaon we use v nails is that we make 30 to 50 frames a day and we need the v nails to hold the joints together until the glue sets up.

Mitre joints, contrary to a previous post, are not end grain joints; they are about 35%end grain and 35% long grain. The long grain to long grain joint is the strongest joint in woodworking and a 35" long grain to long grain joint is, with obvious exceptions, plenty strong enough for picture frames. The exceptions cry out for additional reinforcement and they are very large frames with heavy 1/4" mirrors.

Jennifer mentioned repairing a glue only frame; it was easy to repair because there were no mechanical, metal fastners to deal with. In addition to our frame shop, we also have a busy cabinet and furniture making shop. We do a few repairs because it's the nature of our business for people to bring them to us. All of these repairs would have been much easier if there had been no metal fastners, and, in fact, we're pretty sure the metal fastners hastened the failure of the joints we repaired and made the failure worse that it needed to be.

A well made mitered glue joint takes time to prepare (glue uniformly on both surfaces to be joined and reasonable pressure, not so much as to starve the joint of glue) will result in a very strong joint indeed. It would take more that a fall from 6' to break it, especially if it were made with modern glues. But in the event it did break, it would be easy to repair.

Of course, most of us don't have the time to glue up each corner of a frame; that would take at least an hour per frame, so we use mechanical fastners to hold everything together while the glue sets up, but the mechanical fasteners add nothing to the joint. Mechanical fasteners are no way stronger than the glue joint they facilitate.

I've actually made mitered cabinate doors with only glue and they've held up for years holding panels; some I know are over 20 years old. Most careful woodworkers would not rely on glue alone for mitered doors, but they wouldn't rely on metal fastners, either. But, a picture frame is not a door and doesn't get nearly the same amount of stress, and for its joint, glue alone is more than strong enough.

What if a glue joint fails? Well, all 4 picture frame corners aren't gloing to fail catastrophically at once so there is plenty of warning before everything spills on the floor, and the joint will be very easy to fix.
 
Warren,

The glued joint I repaired was not dropped 6 feet. It was just being moved and set down a little hard.

I don't trust glue only. It may be easier to repair, but if it had v-nails in it, I wouldn't have had to repair this one at all. And this was a waste of this customers time.

Jennifer
 
I can't imagine using one without the other. My two cents...
kaffeetrinker_2.gif
 
We use both...Always both together regardless of how long the glue sets up.

The other day I had to knock a frame apart to re-size it..I wacked at that thing several times with a rubber mallet and it would not knock apart. It was only held together with glue. I have never been able to get my joints to hold that tight with just glue?

Ther is an article in one of the magazines for framers about this very question. Their suggestion is to always use both..
I would have to look up the article and give the mag's name for those interested. I only recall having read something about it as of late.
 
Jennifer,? sure you would have had to repair the frame if it had v nails in it; the corner would have been loose. V nails won't reinforce a poorly made glue joint to the point that the joint won't fail, especially if it were as poorly done as you describe. A well made glue joint won't fail for having just been "set down a little hard."

Trapper, I don't think I understand your point. It seems as if you're making my point for me: you had to bang away at a glue only joined frame with a rubber mallet to get the corners to fail. That's my experience with glue joints, too. I can twist a corner joined only with v nails apart with little effort with my hands. In fact, when we have to take apart glued and nailed frames, we first have to contrive to break the glue joint first and, that done, the v nails yield easily, to a point. Frequently, we lose material as the v nails come out of the failed joint, ruining it. We have special vises set up to help[ remove v nails from joints.
 
And while I'm at it, I'd like to point out that the vast majority of manufactured cabinet doors, the reasonably good ones at least, use cope and stick joints to join the rails and stiles to form the frame that receives the door panel. With stick and cope, the "tennon" is rarely more than 1/2" and the "mortise" 1/2" deep. That isn't much of a joint and isn't nearly as strong as a mitered joint would have been, yet it is glue only. How long do commercial cabinet doors stand up? A heck of a long time.

For our really good stuff, we use tennons at least 1 1/2" and mortises that deep.
 
Originally posted by BUDDY:
...Jim that suggestion you just gave does that amount to the same advise we are always told that the V- nails and/or brads are just a temporary fastener to hold the corner together until the Glue dries. That is to say that the strenght of the brad or v-nail isn't intended to hold the corner to a secure fit ,even if they do squeeze ?... BUDDY
As others have said, the glue holds the corner tight; using only fasteners would result in corners that would work loose in a short time, especially with a lot of handling.

The fasteners hold the corner still while the glue dries, and prevent catastrophic failure later, in the event of impact or other force that could break the glue joint loose.

Yes, each v-nail acts as a wedge, so using too many of them would result in corners that are open on the outside edge; using too few would result in a weak corner. Underpinning machines are designed to clamp the miters tightly together during insertion of the fasteners, so the proper number of v-nails would not create enough wedge action to open the corner up; the grain in most woods will compress enough to accommodate a reasonable number of fasteners. Some v-nails are designed to "pull" the miters together, and that's generally a good thing, but they are more difficult to stack.

I would not recommend using glue alone, or fasteners alone. Both work together to make tight corners stay tight and strong.
 
My 2 cents:

I think that it is very important NOT to touch a mitred surface with your oily fingers to see if it's smooth. I feel that even a little oil on the joint will weaken it a lot. Resist the temptation!

I also feel that the 4 corners should be glued and fastened (nails, v-nails, or thumbnails) and left to sit for a few hours. If glue joints are disturbed during their critical set-up period, I believe that the joint will not as strong as it could be.
 
The more I read this question the more confused I get about why anyone would want to use just one or the other. There have been countless reasons given why they work well together and why.

My first impression was that the question was which ( glue or Tacking devise-brad or v-nail)held the miter together stronger and why.

Jim just gave a very good explanation of the answer to this and i truly thought EVERY framer who has ever made a frame knew the answer to.

I also agree that corners that are correctly GLUED together with modern day glues are frequently if not always knocked apart with a rubber mallet on one side and a block of some kind under the other leg. So the Glue would seem to hold very tightly to say the least. Also in this process the V-nails or brads ( especially if cross nailed will often spilt the corner apart.

I once heard a method of extracting the sparsely but strategically placed Brads by touching a very Hot Soldering Iron to their head which in turn would singe the surrounding wood and more easily allow the extraction of the brad so that the pounding with a mallet wouldn't cause any splitting.

So while the two systems work well together the Glue IMHO is what holds the miter together while the fastener secures it till the glue dries. However if done correctly ( which this separation doesn't sound like) the corner will require a LOT of force to open the corner and definitely much more than just being set down "A Little too hard".

My bet is that corner was about to give before it was moved and your client either didn't know or was LIEING about whether it had fallen from any appreciable Height.

But Most of all anyone who would want to choose one or the other is either very in experienced or is just trying to be cheap. ( "Penny wise and DOLLAR foolish")No insult meant just plain old good sense and it is coming from a host of people.
BUDDY
 
Originally posted by Warren Tucker:
we're pretty sure the metal fastners hastened the failure of the joints we repaired and made the failure worse that it needed to be.

I've actually made mitered cabinate doors with only glue and they've held up for years holding panels; some I know are over 20 years old. strong enough.

What if a glue joint fails? Well, all 4 picture frame corners aren't gloing to fail catastrophically at once so there is plenty of warning before everything spills on the floor, and the joint will be very easy to fix.
Warren,
1. I would love to know how you would come to that conclusion. I fail to see how a metal fastener would hasten the failure of a joint.

2. I have also made many cabinet doors over many years and cabinet doors are dissimilar in several ways from picture frames. The gluing surface area is generally much larger than the majority of picture frames and they generally do not contain the weight that's in a picture frame, they are also not moved around clumsily in motor vehicles or art galleries and generally not subjected to the same forces. Most cabinet makers use joints such as motice and tenon, dowelled or even biscuit joints for maximum strength.

3. I am just plain stunned by the last sentence quoted.
 
Originally posted by osgood:
</font><blockquote>quote:</font><hr />Originally posted by Warren Tucker:
we're pretty sure the metal fastners hastened the failure of the joints we repaired and made the failure worse that it needed to be.

I've actually made mitered cabinate doors with only glue and they've held up for years holding panels; some I know are over 20 years old. strong enough.

What if a glue joint fails? Well, all 4 picture frame corners aren't gloing to fail catastrophically at once so there is plenty of warning before everything spills on the floor, and the joint will be very easy to fix.
Warren,
1. I would love to know how you would come to that conclusion. I fail to see how a metal fastener would hasten the failure of a joint.

2. I have also made many cabinet doors over many years and cabinet doors are dissimilar in several ways from picture frames. The gluing surface area is generally much larger than the majority of picture frames and they generally do not contain the weight that's in a picture frame, they are also not moved around clumsily in motor vehicles or art galleries and generally not subjected to the same forces. Most cabinet makers use joints such as mortice and tenon, dowelled or even biscuit joints for maximum strength.

3. I am just plain stunned by the last sentence quoted.
</font>[/QUOTE]
 
Originally posted by Warren Tucker:
[qb] we're pretty sure the metal fastners hastened the failure of the joints we repaired and made the failure worse that it needed to be.

I've actually made mitered cabinate doors with only glue and they've held up for years holding panels; some I know are over 20 years old. strong enough.

What if a glue joint fails? Well, all 4 picture frame corners aren't gloing to fail catastrophically at once so there is plenty of warning before everything spills on the floor, and the joint will be very easy to fix.
Warren,
1. I would love to know how you would come to that conclusion. I fail to see how a metal fastener would hasten the failure of a joint.

2. I have also made many cabinet doors over many years and cabinet doors are dissimilar in several ways from picture frames. The gluing surface area is generally much larger than the majority of picture frames and they generally do not contain the weight that's in a picture frame, they are also not moved around clumsily in motor vehicles or art galleries and generally not subjected to the same forces. Most traditional cabinet makers use joints such as mortice and tenon, dowelled or even biscuit joints for more strength.

3. I am just plain stunned by the last sentence quoted.
 
Warren,
I don't mean to argue with you, but in this one case, the joint seemed to be glued and joined very well, with the exception of no v-nails. It was not dropped, it was just set roughly down to the ground in a move and only the bottom two corners where broken (with a clean break in the joint). And to be honest, I can't imagine a picture being dropped 6 feet and the glass not breaking.

I'm just saying for me and my shop,I am not willing to risk my reputation as a framer on just glue in the corners! Why would you, when v-nails are available!It just doesn't seem smart.

Jennifer
 
Ormond, I had to read all three posts to see if I got everything. They all seem to be the same so I'll answer the questions in the last one in case there were modifications I missed.

If you can't see how a metal fastner can hasten the failure of a joint, you haven'r repaired much furniture. A classic example can be found in many
wood panels that have been screwed to sides (in the case of a chest) or to skirts in the case if a table. The metal screws hold the panel down admirably, but they also keep it from expanding and, more importantly, contracting resulting in the many split table and dresser tops we've repaired over the years. Another near classic example is the loose chair leg that's been screwed in an amature effort at repair. As to picture frames, I think the v nails actually inhibit natural wood movement in frame corners hastening failure. They sure make repair difficult.

I don't know to say about #2 because if you believe cabinet doors are under less stress than a typical picture frame, there's not much I can say to you except cabinet doors are way more stressed every day. My girls used to swing on them. people slam them. I've actually seen a kid sitting on the edge of one. People also move their cabinets (called case goods in the trade). I just looked at some raised panel doors being glued up in our cabinet shop. The rails and stiles are between 2 and 2 1/2" wide, a little wider than a typical picture frame, I guess. I'm embarassed to say that the joints are stick and cope. There are no metal fastners in them, and they don't need any because they can be easily glued up with bar clamps. Several of these doors are 40" tall. If picture frames could be as easily clamped, there'd probably be fewer v nails used in them.

We use v nails in every frame we make, but only because the v nails allow us to join the frames quickly, not because they add any strength, because they don't. We've got two Cassese 486's and a Cassese 4095, all light industrial joiners, and we use 'em every day; we'd be out of business without them.

As to the last sentence you refer to, I don't see anything particularly stunning about it (and I'd be inclined to since I wrote it). It's just ordinary with an awkwardly placed phrase ("at once"). Or is it the sentiment? Actually I was just pointing out that in the event of a glued corner failure, the consequences would be minor and the cure easy. The same would hold true for a glued and nailed corner with the exception that the cure would be more problematic.

V nailers are an essential tool of the modern picture framer, but there is no virture in using one. We also have a light industrial version of the Hoffman router (a jumped up thumbnailer) and we use it, too, with the certain knowledge that it in fact produces a joint weaker than one with glue alone.

We actually experimented years ago with glue only joints; we had 16 Stanley corner vises so we could glue up corners and let them set. We concluded with good evidence that the joints were very strong and that v nails addeded nothing to strength. After a month or so, we started using v nails again for speed, but not for strength. Ever heard of the Baruch company? They manufactured the Master Clamp for people who did not want to use metal fastners in their frame corners. I've met quite a few framers who consider no fastners a virture and who go to some trouble to avoid using them. Not me; I'm for speed.
 
Jennifer never say never. LOL I can personaly atest to the very things you can't imagine.

I forget the Molding number now but it is a massive ( about 3-4 inches) dark walnut molding from LJ with an interior decorative gold lip that we used to frame an over sized Cross stitched image of "Oak Alley" Plantation (appx.30 x48 ins,)It had a conservation clear GLASS glazing and it was my wife Marie's pride and joy . We took it home after it hung in the shop for some months.

Not knowing any better I used heavy gauge wire which I strung from the bottom leg to the two sides through strap hangers and back to the bottom leg .

It was hung on two strong lead anchored screws high above the mantle on our brick wall and stayed there for about a few months. One day upon arriving home i entered the house first and thought we had been robbed. In our front room on the floor in front of the fire place were the remnants of Terra Cotta angles Marie had placed on and in front of the Fire place and mantel. The framed piec was lying on the floor upside down in the middle of them.

Upon further examination I found that the vibration from the truck traffic in the street had caused the straps to cut the wire on one side and the entire frame had flipped off the wall onto the mantel severing all the angles then it flipped off the mantel on the stoop in front of the fire place smashing more angels .

The only damage the frame had incurred was that the Framers pins had been Jared loose Not out and there was a slight scratch on the moulding which when touched up couldn't be seen, The Glass didn't break ( not even chip) the corners of the frame didn't seperate and all i needed to do was re-pin the needle work and replace the dust cover and use a Z-Bar hanger and that same frame hung in my house until Katrina. After Katrina it had floated down to the ground and the corners were still fairly intact, the finish of the moulding was ruined and the glass was still whole .The Mats were ruined from the flood and the work was soiled and needed to be remounted but it still was in fair shape, considering all it had been through.

And both times it was hung and came down ( floated or fell) from over 9-10 feet up.

So this is why I have some problems with the stories I am reading. And i am by no means a Chop and Join expert like many have professed to be ,nor am I now or ever been a wood working expert as some here are.
BUDDY
 
Originally posted by Warren Tucker:

If you can't see how a metal fastner can hasten the failure of a joint, you haven'r repaired much furniture. A classic example can be found in many
wood panels that have been screwed to sides (in the case of a chest) or to skirts in the case if a table.
Warren,
In fact, I have repaired and restored many pieces of furniture, just like you describe, in my previous occupation as a custom period style furniture manufacturer and restorer, and the situation you describe has absolutey no parallel in the manufacture of a picture frame!

It's my opinion that the vee nails in a glued joint reinforce the joint to make it less likely for the glue joint to be broken under pressure form mistreatment. Your opinion is obviously different.

I conducted (unscientific) personal pressure tests on both glued joints, and glued joints including vee nails, some time back and those tests convinced me that the vee nails added a very significant strength advantage.

Actually I was just pointing out that in the event of a glued corner failure, the consequences would be minor and the cure easy.
Your experience is obviously different to mine. Broken glass and damaged artwork have often been the result in my experience. This is hardly minor or cured easily.

As far as cabinet doors are concerned, with children swinging on them, I wouldn't imagine there would be a lot of cabinet doors that have rails and stiles that have the small gluing surface areas such as many picture frames have. eg half inch or one inch wide mouldings.

We are entitled to disagree!
 
When breaking old frames (for throwing out) I do what most do, put one corner on the floor and apply sharp pressure.

No nails? It explodes!

Nails? You have to add a bit more violence.

When I am asked to reduce the size of an old frame by, say, half an inch all round it would be great if it was just glued, but it never is!

When I am asked to repair gaping mitres or frames held together by nothing but the backing board, most have been glued only. They go back 'V' nailed.

So, in answer to original question posed (Glue vs nails) BOTH!
 
Th article I was talking about was written by Jim Miller in the spring 2006 issue of production. or maybe it was PFM..??? Jim should be able to tell ya which mag it was in..BTW..good job..chart and all!
The point I was trying to make Warren was that I had no idea that glue and glue alone was , or could be that strong.
Not trying to be argumentative with anyone or wanting to plagerize anything you may have said. I just simply did not know that my glue could be that strong. I have played it back in my heard over and over again to see what if anything I may have done differently and I can't figure it out. Why did this piece hold on and on..wack after wack while many others gave away after the first blow...Beats me..!
But even then I would want still to use both V=Nail and Glue..Seems to me two chances are better than one. If the v-nail gives out..ya still got the glue and if the glue gives way, ya still got the v-nail.
If they both give out at the same time, well then ya got another job to do..
I am glad however that this one time there was no nail. It has always been my experience that taking a frame apart with a V-nail in it is challenging.
You tell me Warren that your set up for doing this with vises??? I would like to hear more on this? I have never been able to successfully re-move a v-nail without maling a mess out of it..I always have to cut the frame down and start over. I can never ever re-insert a v-nail where I just took one out.I don't think you are saying this..but are saying that they can be removed easy enough???
Eagerly waiting to learn how to do this.
 
We glue the corners first, usually in 4 vises at the same time, or at least 2, if the frame is too small, wait a few minutes for the glue to "set up", then v-nail. It doesn't take an hour to glue a frame, if you use more than one vise at a time. I've glued and then v-nailed immediately and had problems with the joints being jarred out of whack, often enough to not do that anymore, even when I'm in a hurry, hence the vises first. I've never had a problem when they're glued first.

How timely this discussion. This morning I started to fit a frame with the Fletcher gun, didn't notice that it had not yet been v-nailed. Corner popped.

Later, I dropped a frame, with a fillet, on the carpeted floor (I'm only 5'3", and it dropped from my waist level.) It hit corner first. Two sides fell apart on the frame, two on the fillet. It had been glued, but not yet v-nailed.

I have learned over the years that too much glue can be as bad as not enough, and I don't understand how a framer can get so much glue all over the front of their apron. I don't even wear an apron, and rarely get glue on my clothes. My fingers, yes.

I've also rarely had a problem getting a frame to come apart when I want it to, glue and nails and all, not by whacking at it with a hammer, but by resting the frame on one corner and pushing down. Sometimes the wood does give way a little, but wouldn't that be better than having hammer dents all over it??

So...does the fact that the corner on the frame I fitted popped, and the one I dropped from, say, 3 feet (I just measured) on carpet mean that I'm not using enough glue, or does it mean that gluing and nailing, be it v-nails, brads, thumbnails, wedges, etc. together is vital to the strength of the miters?? I believe it to be the latter.
 
I used to watch, what's his name - ah, Norm Abrams, on the New Yankee Workshop on PBS (or was that Old Yankee Workshop?) -

Anyhow, I always used to get a huge kick out of what I called his "Earthquake Proof Joins." I mean, ole Norm has every toy in the store when it comes to woodworking - and he used waterproof glue, biscuits, plus nails on many, many of his projects.

And in my previous posts when I say "nails" I mean brads, not V-nails. I use brads - and the use of nails and glue together allow me to join a frame in a few minutes, stopping only to putty nail holes before on to the next corner. And then I do set them aside to set up however.

And I have been hankering for one of those little mini-biscuit joiners. LOL! (But then when I watch that guy with the hand tools build stuff I want to go out and get me some chisels and spoke shaves!)
 
BrianInOmaha-I still use a Thumbnailer, unless I'm doing a massive (3 1/2" or wider) moulding. There was a similar thread about Thumbnailers a few weeks ago. Mine is old--I'm getting ready to change the bit again--first time in several years and I've misplaced my little wrench.

I use the Thumbnailer because I don't have room for a V-nailer. I also don't like the holes in the sides of the moulding made by brads or nails. This seems like a nice compromise. I glue and Thumbnail, and just to be on the safe side, let the joins sit in a vise for 30 minutes or so. We are a small shop and have the time to do this. If we were a production shop, we would definitely have a V-Nailer.
 
<blockquote>kwote:</font><hr />Originally posted by David N Waldmann:
Glue is a chemical bond, not mechanical, so the "tooth" only increases surface area and then you are on a technical journey of calculating adhesive versus cohesive strength as well as the fill characteristics of the glue in question.</font>[/QUOTE]


Thats why I supposed, it is hardly surprising that glue reaches the same chemical state regardless of tooth offered but what I do know is that the joins with the same adhesive for my corners from the guillotine are not even close to the strength of those from my twinsaw. Thus my thought that when a guillotine is used the additional use of a nail not only offers it's own strength but it creates a more easily penetrated joint for the glue as the nail rips through.

Perhaps your "technical journey" to compare the possibilities of these various issues would be beneficial David, was that an offer you were making?
 
lance the concept of tooth can even aply to the very smooth surface of a patel painting. You may rememeber the thred where we discussed a special grade of snad paper used with pastels to give it more tooth. The normal paper had tooth as well just the rough textur e of the grit od the extremly fine sand paper had more.

so too is the guillitine cut miter and the saw cut mither they booth have tooth only the saw is a rougher cut and hence it has more. But there is tooth in every cut of wood, Also there is definet differeance in how much Glue you aplly . Too little not enough bond too much howver amy produce the same effect for a slightly different reason.

Glue needs to seep into the crevases of the wood ( tooth and dry to diorm that bond and it occurs better under direct pressure , If you slather the glue on the joint it doesn't dry throughly ( although it appears dry to the eye) and the joint isn't nearly as firm. Also IMHO ( because I don't use one) a bicut joiner causes more tooth and some of it inbtween the wood which makes a more securely glued joint .The addition of any "NAILS are to hold the joint till the prperly glued joint cna dry and cure. I'll bet even Norm Abrams would agree.You need both but easily spreading joints after glueing and nailing ( other than before properr cureing time ) may strongly suggest youneed to rethink your process. IMHO.

Some of todays glues when properly applyed and secured, vised will hold as well if not better than the wood itself. But Ask ole Norm I'll bet he concurrs.I've seeen segments of the "New Yankee workshop " where Norm made a table top by GLUEING and Squeezeing planks in a vise where nails would really secure much of anything and they would ruin the desired smooth finish,However he did use Biscuts a lot but that was to add surface area and tooth where there was none.
LOL
BUDDY
 
Originally posted by Lance E:
Perhaps your "technical journey" to compare the possibilities of these various issues would be beneficial David, was that an offer you were making?
I'm sorry Lance, but I have only enough knowledge of that subject to be dangerous. I was only trying to point out that chemicals (such as glue) work on a level that is unseen by the naked eye.
 
I suspect that those of us who are older veteran framers aren't going to be swayed much by an argument such as this but those who are starting out may need just such advice on joining frames. With that in mind, I would allow that experience should be one of the deciding factors in deciding one technique over another and experience is what most new framers lack. Therefore it is up to us to keep a level of experience and factual information in the conversation and allow those who are seeking help make up their own minds by experimentation or following some means of procedure to decide what works for them.

Obviously there are multiple methods of joining frame miters depending on the equipment at hand and the druthers of the technician doing the work. There may not be an ultimate "wrong" or "right" way to join a frame corner using one or the other of the methods mentioned on this thread.

I started out by joining miters using nails, glue, corner vises, and putty. That is what I had to work with at the time. I STILL join using this method when I have a deep shadowbox to build. But I bought an underpinner many years ago because that was the method that made the most sense to me as I became more trained and experienced in handling mitered joints of different species and densities of wood. I went to trade shows and watched demonstrations of underpinners and I made a conscious decision to buy the machine that I have used ever since.

I have had no returns for broken miters, I have not had a single complaint in 16 years of underpinning frames, and I have not had any undue problems breaking down a frame over and above the normal problems encountered in breaking a reinforced glue joint. So does that make my methods the best?? I don't think so. It simply means that I have found a method of joining miters that I am comfortable doing. Right, wrong, maybe somewhere in between, that would be very difficult to judge and I would challenge anyone to label my method above or below any other method without ample physical and measureable proof of such.

So my advice to newer framers is to read these posts and learn from them. Try out some of the methods with the tools you have to work with and decide for yourself which method or combination of methods will work best for your style of framing and level of experience. And when the time comes and your finances dictate, maybe you will decide to move up to a faster easier more efficient method based on what you have learned and your own personal comfort level.

Framerguy
 
It has been my observation over the years that when corners are not glued first they are just not tight enough for my satisfaction. I am very fussy about corners and many of my customers have commented on it. It may take a little longer to glue, but I never worry about getting something back because it fell apart, or the corners start splitting apart. It takes way less time to glue and nail, than to repair something that I can't charge for because it was my own fault that it needed repair.
 
In the case of Super-glue, Gorilla glue, or two-part epoxy I would agree with the "Chemical" bond theory; but in the case of all PVAs from Elmers to Corner Weld there just is no "Chemical" activity.

PVA is inert. That's why we can use it as a conservative glue directly on some items.

At the risk starting a firestorm, David, you need to go check your math. 35% and 35% do not add up to 100%. But aside from your math on a mitre joint [50%end-grain and 50%long-grain] what matters here is the surface area of the long-grain joint.

If the joint is on a 2" wide moulding 1" thick then the two surface area are disparent as such:

Mitre: [given: the 45 mitre surface on a 2x1 is 3x1] so for a 50% long-grain surface on said mitre is 1.5 square inches.

Cope and stick: [given: tenon thickness is 1/3 the thickness of the moulding/board] so for a 2x1 the surface area will be [using your 1/2" long tenon and mortice] 1/3"+1/2"+1/3"+1/2"+1/3x2" for a total bond surface of 4" which is 100% long-grain bonding, and too small to be affected by seasonal migration, which allows your children to "swing" on the doors.

The reason for a mechanical bond [v-nails or spikes and brads] at the time of gluing is to draw the bond together into a greater than 1lb tension [glue in mitre vise than nail when dry] and less than 50lb tension resulting in a starved joint [no glue].

A PVA bond happens mostly from surface tension and very little "tooth" or penitration into the grain. Which is why all joints (that can be) in furniture (that receive incredable stress) are planed to a glass smooth joint. [I'm speaking as a woodworker who makes furniture with hand-planes as appossed to IKEA.]

What penitrates is the water in the glue; only carrying a fraction of adhesive. This results in a thin layer between the wood surfaces that has filled any tiny nooks and cranies and resulted in a shear bond that is a result of surface tension.

The V-nails serve two purposes. 1) to hold the bond in place while it drys (it takes MANY hours for the moisture to "wick" away from the bonding wood) and 2) if the glue bond fails the nails or V-nails will hold the frame "whole" whilest the customer rushes (usually within a year or six) it to a restoritive agent (framer).

IF you are in the habit of gluing in a vice then V-nailing, be aware that any shock or jarring to the still moist wood and glue bond will result in the degridation of the bond that may or maynot be evident right away.

So spread a nice thin coat all over all surfaces to bond, then V-nail with a minimum amount of nails neccessary to hold the bond correctly and let rest at least over-night before fitting.

If you doubt me, as for the strength of a glue joint [long-grain to long-grain], simply take two blocks of wood 3/4" thick, 2"-3" wide and about 6" long, plane a glass smooth joint (or sand to 600 grit), apply a 2mm dot of PVA every inch on one side, push the blocks together and slide back and forth untill the bond takes place... now, without rocking or bending try pulling them directly apart.

Now put them back together, re-establish the bond by sliding them back and forth untill they resist. Set them aside for a few days. Now try to break the bond. Trapper, you can use your mallet. :D

As for nails rusting, v-nails falling out and glue joint opening up on the inside... these are all due to the drying out of moulding that started at more than 4% humidity levels; NOT seasonal wood swell and shrink (migration). And the drying out will not occur more pronounced on the top half because of hotter dryer tempature in a room. The moisture is IN the hotter higher and dryer near the floor, so the frame drys equally. [Thank you Getty Museum].

BTW: Norm Abrams is a carpenter and is still learning how to build furniture. But he is better at promoting woodworking than Martha was at framing; so we woodworkers still love him.
 
Originally posted by Baer Charlton:
In the case of Super-glue, Gorilla glue, or two-part epoxy I would agree with the "Chemical" bond theory; but in the case of all PVAs from Elmers to Corner Weld there just is no "Chemical" activity...
Welcome home, Baer.

Glues, including PVA, are chemical concoctions. That aside, I think David was probably referring to the molecular characteristics of bonding, which is chemically related, whether the adhesive type is drying, reactive, or pressure-sensitive, or heat activated.
 
No firstorm, Baer, certainly not for a typo. I don't understand your analysis of a stick and cope cabinet door joint. I'll give you 1" thickness of the rails and stiles since their thickness doesn't matter. I went over to the cabinet shop and picked up some stick and cope test pieces (actually, the sticking is square) from a current job. They happen to be 2" wide.

Looking carefully at the "tennon" piece (in quotes because it's not actually a tennon since it has no shoulders; it's 2" long.), I see a 1/2" tennon whose cheeks have a surface area of 2 square inches (top and bottom of the "tennon.") The end of the "tennon' is end grain and its thickness doesn't count as surface area as it doesn't touch anything (there has to be a little area for excess glue inside the "mortise." Now if this joint were a tongue and groove joint, I might argue for the end of the tongue since it would be long grain.

For the life of me, I can't see more than the two square inches of surface area to mate with the sides of the "mortise." Maybe different sticking would add a little but the end of the rail would still be all end grain so it wouldn't account for much. Now there is, according to your analysis 1.5 square inches on each of the mating surfaces of a mitre joint. There's 1.5 sq. in. of mating surface on the mitre joint and 2 sq. in. on the stick and cope. The door has a 33.33% advantage. A mitre joint would probably be a little less than 66.6 % as strong. Still plenty strong enough for a picture frame.

As an experiment mostly to satisfy myself (and I encourage everyone interested in this topic to do the same) I took a length of poplar 3/4 x 2", and cut and mitered 4 pieces. I joined 2 with with glue in a vise and left them for two hours. I joined the other two with 2 12mm Cassese v nails. I could break apart the v nail joined corner with little trouble with my hands. I couldn't break apart the glued joint. The legs on all 4 pieces were 8" to reduce leverage. As far as I can tell, the added strength afforded by the v nails is negligible, really not worth the effort.
 
IS there anybody, in any of these exhaustive posts, that DOESN'T think there should be glue AND fasteners of some sort in them there corners?

I am having a hard time following the entire discussion but I think some others have lost track of the question.
 
Yeah, me, but only in the circumstance I mentioned earlier. Anyone who is letting glued corners set up in a vise and then inserting v nails is wasting his time making the corner no stronger and actually in some instances, as Baer pointed out, making the joint weaker.

I think I can make the argument that if time allowed, one might prefer gluing up a frame with no fasteners in the corners. We've done just that for at least 100 frames before going back to v nails for speed. We started using only glue because our original Cassese 810's wouldn't insert v nails well in hard woods. With the new industrial Cassese v nailers, the original problem doesn't present itself.

We make a lot of frames every week, 150 to 200 and have been for many years and we pay attention to how we make them. Believe me, we've got a handle on frame making.
 
Trapper, we use the side vise, not the tail vise, on a woodworking bench. The vise has wooden faces 18" long. I think any well mounted woodworking vise whose jaws are faced with long wooden faces should work.

First, you have to decide how you want the joint to come apart. If you are shortening a frame, you want to place the leg in the vice whose face you don't mind ruining (that would the the one that's too long. We usually cushon the face of this leg with scrap matboard. With one leg firmly in the vise (the joint just sticking out enough so that the back face of the vise isn't supporting the free leg) and the other free, start gently tapping on the back of the free leg, gradually driving the v nails out of its back (and occasionally driving them through the front of the piece in the vise). You don't care if the v nails come through the front of the leg in the vise because that's the leg you want to shorten.

After you have seperated the legs, use a pair of side cutters to remove the v nails in the leg they're still in. We place the leg on a flat surface, grap a v nail witht the side cutters and lift the end and rapidly bring it down (lifting and pulling down with the side cutters) on the surface of the table. That usually gets the v nail out. If the v nails are stacked, do one at a time.

Of course, before you can even think about removing the v nails, you have to break the glue joints. We haven't worked out a method that works in all instances. When all else fails you can try placing one corner on a table or on the floor and gently applying pressure on the opposite corner. That will usually break the joint with minimal damage.
 
I am going out on a limb here....ready?

I have been just gluing my frames for the last 7 years and have had no problems whatsoever. Ok I said it! Its out in the open!

The previous 7 years of my framing career involved nailing and gluing. Was VERY unsure of the glue only way of doing it, until I tried it. They hold up beautifully, no nailholes to fill...and if it is a large frame, I will use corner braces and/or hang the picture from the bottom.

Okay, let the brads fly
smileyshot22.gif
 
We have read here that a glued-only frame would not disintegrate in the event of one loose corner.

I don't buy that, because I've seen the results when it happens. Customers bring us frames like that to repair once in a while, and they are usually in more than one piece.

When one corner breaks loose -- for whatever reason -- additional stress is imposed on at least one other corner. When that happens, there is a sort of "domino effect". The other corners fail in succession until the frame's contents fall out.

I know one customer who suffered costly damage to a piece of antique furniture when, in the middle of a night, the frame hanging above it fell apart.

It doesn't always happen that way, but the hazard is well known. Why risk it?
 
Originally posted by Warren Tucker:
When all else fails you can try placing one corner on a table or on the floor and gently applying pressure on the opposite corner. That will usually break the joint with minimal damage.

Warren, if that usually works, with minimal damage, why don't you try that first, instead of after all else fails?? Wouldn't that be a "waste" of time"?

I, for one, as I stated earlier, use the vise first, not to let the glue dry (I did not say that), but to set up, before v-nailing. I don't conseider that a waste of my time. Instead, I consider it a waste of time when the v-nailer pops that miter askew when the glue is wet, and I have to dig the v-nails out, sand it down, reglue, and do it again.

I also wouldn't tell anyone who has found what works for them that their way is a waste of time. But then, we're a sma;ll operation. On the other hand, our time is valuable to us too. We have found what works for us, and until something better comes along, and we'd welcome any other ideas, we'll stick to that. We know our way around framing too, and we've learned that fast is not always best.

We don't do 150 to 200 frames a week, but what we do is still quality work and we intend to keep focusing on that. It may take us a bit longer, but it's worth it.
 
Back
Top