In Need of a Tightly Joined Corner

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John 1234

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Currently, I am having trouble with certain types of mouldings (usually heavier types) in joining the corners tightly.
Could it be the wood glue? Could it be the placement of the v-nail?
When I'm done gluing and nailing, there is slight separation, (but enough) in the corners when looking at them from the front. All my corner samples from the supplier are soooo tight! How do I get this?? Please advise. Your help is appreciated.
 
I assume you are talking about chop. Can you lay the frame on your table and have it fit together perfectly before assembly? It is easy to join 2 legs of a frame when the miter isn't perfect and have it look good. The problem is that every leg you add to the frame multiplies the inacuracy in the miter. It then becomes impossible to make all four sides join properly. Send the chop back to your supplier as you have joined it (for proof) and ask them to check their saw or chopper.
 
<BLOCKQUOTE>quote:</font><HR>Originally posted by John 1234:
Currently, I am having trouble with certain types of mouldings (usually heavier types) in joining the corners tightly.
Could it be the wood glue? Could it be the placement of the v-nail?
When I'm done gluing and nailing, there is slight separation, (but enough) in the corners when looking at them from the front. All my corner samples from the supplier are soooo tight! How do I get this?? Please advise. Your help is appreciated.<HR></BLOCKQUOTE>

I currently by length moulding. I have had situations where the moulding has been warped and after I had the first three corners done the fourth would throw of the third for example.
But, the mitre is good. The join itself is good, it is just that the seam in the joint is separated, could be a sixteenth of an inch, sometimes an eighth of an inch. It seems that the join is tight on the back of the frame it just seems loose on the front.
 
Hard to tell without being there but it sounds like an equipment alignment problem to me. Check your saw or chopper to make sure your in and out feed tables are level with the cutting area. If they were higher they could cause your moulding to flex down as you were cutting it causing a gap at the top of your frame joint. Next be sure all the glue and such is cleaned off your v-nailer, seems silly but I have gone into shops that have a large buildup on their machines and they don't understand why they have bad joints. Check the distributer head of your v-nailer to make sure it's level with the machine's table and make sure your work table is level with your machine. Some v-nailers have adjustable fences that tilt in and out that actually adjust the verticle alignment of the miter so check that. The most common problem I've run across is an unlevel work bench holding your frame legs slightly off. Not a problem with a light frame as the v-nailer has enough power to pull the moulding into alignment but not larger heavier frames. That's all I can think of for now. Let me know...
Frank
 
Amoungst these other possibilities is the type of V-nail, seems like you may need a sharper nail.
 
Make sure your chopper knives or saw blades are sharp. With even slightly dull or damaged cutting tools, mouldings sometimes try to "creep" away from the tool.

Try gluing the miters in vices on the benchtop; let them dry before V-nailing. If you're not sure whether the problem is your miter cuts or your v-nailer, this is a way to find out.

I often glue/vice corners before v-nailing to get the tightest possible corners. Especially, pre-gluing avoids the slight separation of miters at the outside of the corner. If you have tight miters and let them dry for about 1/2 hour (with CornerWeld glue, that's enough), then you should not need to be concerned about breaking them loose during nailing.
 
Also there are 2 general types of v-nails. One for hardwood and one for softwoods. The sharp edge of the hardwood nail is beveled on both sides whereas the softwood nail is bevelled on one side similar to the C&H 1200SE mat cutter blade. If you try to use the softwood nail on hardwood it tends to bend backwards badly and even split causing a bad joint. But on softwoods it can really suck a joint together.
Another thing to check if you're using a 'carpenters" type of miter saw is if the saw blade is set at a 90º angle to the table.
 
Frank, perhaps you could answer a question for me. My local recommended the hardwood nails for everything. Another source recommended the softwood nails for everything. As is the case with latex vs. oil paint for your house, there's no middle. Other than identifying the woods, is there indeed a "universal" strength for v-nails? I think I'm using soft: what's the deal?
 
When I was introduced to Masterclamp (www.masterclamp.com) I found it to be the best joining/pre-joining clamp available. I have been using it for about 8 months now, and I found that if I glue-join my frames THEN underpin it, I get the tightest corners imaginable. If you use either the V5QRA or V8QRA, there is also an angle adjustability feature that compensates for very slightly or severly bad miters. If you're going to Decorexpo 2001, I'll be showing off this nifty clamp on Pier 90.

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Seth J. Bogdanove, CPF
21 years framing and still loving it
 
MM, there is no way you should use a "blunt" hardwood nail to join soft wood types, there is also a "medium" nail (code 50) in the Alphamacchine (Mite... something in the US) range. Using a hardwood nail will rip the soft wood and result in a less than desireable join with little strength. Experience is the best way to judge correct nails.
 
MM: As far as I know there is no difference in strength between the hard or soft v-nails, just a difference in the grind on the end. Hardwood nails are ground on both sides of the nail so they will drive straight into the wood. Hardwood v-nails work on everything if you were only going to use one type these would be them. The advantage of the softwood v-nails is the one sided grind on the end pulls the edges of the joint together a little tighter. This is possible as softwood has a little give to it and often the miter cut is a little fuzzy and can crush a little. This would give you a better joint. Softer woods would be like pine, poplar, basswood and such. If you can make a dent in the back with your fingernail easily then you can and should use the softwood nails.
Hardwoods on the other hand have very little give to them. If you use softwood nails often the nail will give before the wood does. What it will do is curve backwards, sometimes splitting in two and (if you don't have any extra moulding) blow out the back edge of the moulding. That sucks. Hardwoods would be oak, ash, maple, ramin and such. It's a little hard to see but if you check your nails with a magnifying glass you can see what I'm saying about the grind. Try both on some hardwood scraps and knock the joints apart. Hope this helps (or even makes sense).

By the way a painter friend of mine likes to use oil based primer with acrylic latex paint over it on his houses. They seem to last a long time so maybe thats the best compromise.


[This message has been edited by Frank (edited March 05, 2001).]
 
Hey 1234--

The best advice I have for you is to back up your cuts on each pass. Once you cut your first cut, go back and take a 1/16 to an 1/8 of an inch off. On the second cut, measure your cut an extra 1/8" (example: on a 20" lenght, measure 20 1/8" on the first pass and go back and shave the 1/8" off on the second pass).
This is called a stress free cut. Carpenters use it for finish cuts to protect against roll and pitch in the cut. The blades are moving really fast as they pass through a piece of moulding, but the harder the wood, the more resistence is put on the blades. Your blades have to clear all that wood out before it can continue so if the wood is hard or the cut is too fast, the blades will crawl on top of the moulding (meaning that the force of the blades will push the moulding backwards a bit.)

I also vise/glue some of the harder moulding before I shoot a v-nail through and sometimes even use real nails (HOW OLD SCHOOL!) on some of the taller profiles. I'd rather have a couple of nail holes on the side than gaps you could drive a truck through on the top.

Anyway, that's how I do it and hope I can be of some service.

I like posts like this and will post one on filets later tonight. Later world.

Rick

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If you don't take care of your tools, they won't take care of you.
 
Originally posted by MerpsMom:
"...My local recommended the hardwood nails for everything. Another source recommended the softwood nails for everything..."

I have used the softwood vnails in hardwood successfully by turning them upside down, so that the dull end goes into the wood. But that doesn't work the other way'round -- hardwood vnails won't work in softwood; they just rip through it.

Bogframe's right about the MasterClamps. After seeing his presentation in Las Vegas, I just had to have a set of 'em. They arrived a couple of weeks later from United.

They are fast & easy to use, very well made, lightweight and accurate. I bought four of the adjustable ones, which was overkill. That feature is handy for poorly-cut miters, but I haven't had to use the adjustments yet. I suggest buying two adjustable and two fixed.

One word of caution: The maker suggests that these vices make corners so tight that the need for nailing is eliminated, and that's just not right. No matter how tight the corner, and no matter how good the glue, the bond will eventually fail. If there's nothing mechanical holding it together when that happens, the frame literally falls apart.
Click to expand...
 
<BLOCKQUOTE>quote:</font><HR>Originally posted by Bogframe:
When I was introduced to Masterclamp (www.masterclamp.com) I found it to be the best joining/pre-joining clamp available. I have been using it for about 8 months now, and I found that if I glue-join my frames THEN underpin it, I get the tightest corners imaginable. If you use either the V5QRA or V8QRA, there is also an angle adjustability feature that compensates for very slightly or severly bad miters. If you're going to Decorexpo 2001, I'll be showing off this nifty clamp on Pier 90.

<HR></BLOCKQUOTE>
I am going to Decorexpo2001. Look forward to seeing these clamps in action. See you there.
 
Jim says: "One word of caution: The maker suggests that these vices make corners so tight that the need for nailing is eliminated, and that's just not right. No matter how tight the corner, and no matter how good the glue, the bond will eventually fail. If there's nothing mechanical holding it together when that happens, the frame literally falls apart."
He's right...I disagree with the maker on this point. I use these clamps to glue-join a frame before I underpin and nail...it eliminates gappping, and makes for the tightest corners I've seen...Wait till you see the new shadow box model!
smile.gif

Seth J. Bogdanove, CPF
21 years of framing
and still loving it

[This message has been edited by Bogframe (edited March 06, 2001).]
 
Related question-

I have a problem with the V-Nails not going all the way in some hard woods. They will stick out the back about 1/16"-1/8". (Normally about 1/16".) I have checked the pressure on my compressor, and I think that the driver is perfectly straight. I have talked to customer support, and done a lot of fiddling with the machine. Now I leave it in the hands of the EXPERTS.
smile.gif


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Sue May :)
"Everyone is born right-handed, only the greatest can over come it!"
 
I took a class in Atlanta where the instructor addressed the problem of v-nails not fully embedding. She said to shoot the same spot without any v-nails and the hammer from the underpinner would push the v-nail further into the wood. We have a MitreMite VN2 and this has worked for us.
Ruth
 
In my VN2+1 and VN42 v-nailers, 95 PSI is enough to drive a 15mm v-nail into the hardest woods we've ever encountered.

Maybe other makes require more air pressure, but air is air and pressure is pressure. If your machine requires more than 100 PSI for *any* wood, check out your pneumatic cylinders. If they are worn or in need of lubrication, that could cause weak performance.

Once a month, I disconnect the air supply (quick connector) at the machine and squirt a 3 or 4 drops of pneumatic lubricant into the air-in port.

13 years, no problems.
 
After using the Masterclamp for a bit, I agree completely that the best join is to allow the glue to set and then V-nail it after a hard set. I dimly remember Mr. Baruch & Unca Boggy saying 15-20 minutes and am being anal so I think we do 30 or so.
 
I'll probably tomorrow regret asking this. In the beginning, we had little bitty clamps to hold moulding, glue on the mitres. Then, glue on the mitres, nails, and vises. Then glue and v-nails. All in the name of production speed and higher quality. Where are you drawing the line? Is this a stupid question? On tough profiles, I vise, glue, nail or v-nail. Are you factoring in your time on the vises-to-underpinner, or does it come down to a "perception" that one is better than the other? Does it work out to my idea of quality vs. yours? Should I have gone to bed an hour ago? Perfect we try to be, OCD we try to avoid?
 
After having trouble with a joint yesterday I came up with a solution that may help, using bundle wrap (5") to wrap the frame so as it pulls tightly across the top and loosely along the bottom pulling the top together. I did four seperate wraps (just inside each leg of moulding) it pulled together a join that had been nailed but pushed apart in the nailer (rimu with a resin vein) this left a surprisingly small gap at the back and gave a very strong bond.


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"If at first you DO succeed, try not to look astonished!"
 
Gosh, what a lot of questions, MM! I can try answering them and you'll have to judge whether or not it was a helpful exercise.

1. I don't know.
2. I don't think so.
3. Yes, time is why I think the Masterclamp & underpinner combination is so potent.
4. Perhaps, but I think there are significant differences among all the permutations.
5. Perhaps; I tend to err on the side of caution, I suppose, in things which bother me.
6. Definitely.
7. Yes, but usually unsuccessfully, in my case.
 
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