VNail questions. Identifying and nailing order.

[Larry Peterson]

These aren't exactly the most profound questions but given the excitement of the last few days with BBF, I figured a dull question or two might be OK.

#1. How to identify Medium from Hard nails. I normally keep 10mm Medium nails in my VN42. When I change out to another nail (most often a 10mm hard nail), I usuallly put the nails that were in the nailer in the bin with the other nails of the same type. Usually!!!. The road to h... and all that. Occasionally I forget and just set them down on the back of the nailer intending to put them back in the nailer after I do a single frame. And of course I forget, so now I have this stack(s) of nails that I don't know whether they are Medium or Hard. A visual inspection of both types doesn't show me any differences. I could take each stack and test them on some hard stock but I thought I would ask. There should be a way. If they are visually identical, how do we know that their QC is up to snuff and we aren't getting hard nails in a soft box, etc?

#2. I can't decide if this question is important or not. Do you VNail from the outside in, or from the inside out. I normally VNail from the outside in because if there is a small bit of vertical misalignment it normally is on the outer edge of the molding, or is more noticible on the outer edge and nailing it (actually pressing it down before nailing it) first helps the fit. But what do I know. Not exactly a chicken/egg type of question but I'm currious and am waiting for a glued frame to set before nailing it and had to do something else because I couldn't take the excitment of watching the glue dry.

[Ron Eggers]

am waiting for a glued frame to set before nailing it Sorry, Larry, but that's the only part of your post I have an opinion about, and I may have just misunderstood.

You're waiting for the glue to set before nailing the frame? The main purpose of the nails is to hold the frame together while the glue dries. (Well, also to give it some support if the frame is dropped or if the glue dries TOO much in 20-30 years.)

I know there are framers who will glue the corner, put it in a conventional vice to dry, and then underpin it. I always wonder why they have an underpinner.

I think there is a real risk of the underpinner, or the movement of the frame ONTO the underpinner, compromising the glue joint before it is truly set.

[Larry Peterson]

am waiting for a glued frame to set before nailing it Ron, I shouldn't have put in that last part. I was mixing apples and oranges (or glue/nail and glue/clamp/nail).

I glue and nail two different ways. For smaller frames I glue and nail at the same time. This is the type of nailing I was referring to in the first part of my previous post. Gluing and nailing together doesn't have as much structural strength as a joint glued and clamped but for smaller frames it is better than just nailing.

For larger frames I glue and clamp and nail after the joint is firmly set. Perhaps it's not necessary to VNail, but after reading some threads here, the conventional wisdom seems to say that you do it.

As a woodworker, I have been leary about how good a joint is that is just held with vnails while the glue is setting so I did some tests awhile ago on some hard oak molding. The joints nailed and glued together came apart much easier that the ones that were glued and clamped. In some of the ones that were glued and clamped, the wood broke before the joint.

I'm more familiar with wood glued with the grain and have built tabletops that you could dance on that were held together with just glue; no fasteners of any kind. Frame joints glued semi-across the grain and clamped seems to have less strength that gluing and clamping with the grain but I'm not sure how much less. I'm guessing that clamping puts a minimum of about 100 lbs/sqin on the joint. I doubt if VNailing puts more than 10-20 lbs/sqin. The numbers may be off, but I think the order of magnitude is close; 10 times more pressure from a clamped joint than a nailed joint. The pressure is what makes a good glue joint. If the pressure is low, the joint won't be very strong.

The glue needs to really set when clamping and then nailing. I use Titebond II with a 10 minute set time and normally let it set for at least an hour before nailing.

If I had my druthers (and the extra time and unlimited miter vices), I would glue/clamp/nail everything. I don't, so I only glue/clamp/nail when I think that the extra strength is required.

[Gerard]

Doesn't Titebond have a 24 hour cure time? If so I would think that any stress put on the joint during the set time would weaken the joint. Wouldn't the v-nailer stress the joint? I have never used one but it would seem that if it has enough power to perforate oak it would apply quite a "jar" to the corner. It has been my understanding that glue is always a better fastener for wood than any metal because the wood expands and contracts in time weakening the area around the metal. Also that rust forms on the metal and further weakens the bond. For these reasons I have chosen to use the Thumbnail wedges as an auxillary strengthener for the joint along with the glue and clamp.
In any case it would seem more appropriate to v-nail before the glue has had a chance to "set". Please advise if I am wrong.

[Larry Peterson]

Doesn't Titebond have a 24 hour cure time? Gerard, You are correct about their recommendation about a 24 "cure" time and not stressing the joints during that time.

The question is whether VNailing a joint during the "cure" time is stressing it. I've never gotten a real answer on what they consider stress. I've taken corner joints an hour after they have been glued and clamped and broken them apart but it took an effort to do so. Since the joint is held down by the nailer during the nailing process, I don't know if that places sufficient stress on the joint to weaken it. Joints I have broken apart after being glued/clamped/nailed have seemed pretty strong.

I've used Titebond for many years as a woodworker and love it for that. If I really need to not nail for 24 hours, I would start looking for another glue with a shorter stress-free period. Do any of the framing specific glues I see in my United or other catalogs have a shorter stress period?

[Jerry Ervin]

Larry,

I am using some new v-nails from one of my suppliers, Atlantic Coast Supplies. They have a nail that you use on all woods. So far I love them. They are much sharper than anything else I have ever used. I bet United will have them soon if they don't already. Using just one type v-nail would solve your problem. I often had the same experience.

I have to agree with Ron on the nailing while the glue is wet. As for the order, I nail the position that is directly under the clamp pad first. Then work in or out as needed to get the other two in. Depending on the profile, you can't always get the clamp directly over the outer most or inner most point. I hope this makes since.

Jerry

[Frank Larson]

Originally posted by Larry Peterson:
#1. How to identify Medium from Hard nails. You'll probably need a magnifier to tell the difference. The softwood v-nail is sharpened with a single edge, bevel on the inside, similar to the single edge razor blades for your mat cutter. It's really small and hard to see but it's there. The idea is that the single bevel pulls the joint together with more pressure. Unfortunately in hard woods the nail has a tendency to split or bend backwards and blow out the side of the moulding. So hardwood nails are beveled on both sides allowing the nail to go straight in. I don't use medium but I would assume (risky, I know) that the bevel is a happy medium with a slightly more bevel towards the inside than on the outside. Hardwood nails can be used on all woods it's just that the softwood nails are a little better at pulling the softwoods together.

#2. I can't decide if this question is important or not. Do you VNail from the outside in, or from the inside out.

I've never been sure either and I'm not sure it matters. That said I always nail from the outside in. I like that outside corner to go together as tight as possible and it just seems like it does better when I nail it first. But that may just be my imagination. I always nail together with wet glue. The biggest advantage of a v-nailer is speed and glueing in a vise then nailing is just too slow for me.

[ 07-16-2003, 12:17 AM: Message edited by: Frank Larson ]

[Brian Lehr]

Larry, I can't tell the difference between 1 nail or 2 in strength, so most of the time I use just one nail 2/3 of the way into the moulding (from the outside edge) but that depends on the shape - where the clamp presses. But if I use 2 (on really wide stuff) then the outside goes first, otherwise the gap seems to open even further.

BTW I usually glue, clamp, no nail.

[ 07-16-2003, 02:02 AM: Message edited by: Brian Lehr ]

[Alan Sturgess]

V-Nails do come in a variety of grinds as mentioned in previous comments. I would disagree that hardwood nails work in all types of wood. The best example of different grinds is to consider woods at the ends of the hardness spectrum. To put a blade or v-nail into balsa wood it must be very sharp. Try pushing a flat slotted screw driver into a piece of balsa wood. It will mush into the wood. Try pushing the point of an X-acto blade into the balsa wood and it will slide in easily.

Consider Oak or Maple at the hard end of the spectrum. A sharp nail in the hardwood will follow the easiest route and the nail will curve to follow the grain. That is why the shocked ‘newbie’ to frame joining will be astounded when he can’t figure out what happened when he mistakenly uses a softwood nail in a piece of oak when the grain runs at 45 degrees to the sides – the nail will actually turn 90 degrees inside the wood and exit out the outside edge of the moulding.

Carpenters have known for centuries that the way to drive a nail into hardwood or well dried wood was to hammer the point of the nail on a rock or stone and then hammer it into the wood.

A v-nail works on the same principal. When you try to use a hardwood v-nail in a softwood the nails tends to ‘mush’ in and the joint tends to be loose or wobbly.

There are four available grinds in the industry. – Extra Sharp, Medium /Soft, Hardwood Grind and a MDF grind for those Medium Density Fiberboard mouldings. Not all companies making underpinners make the same grind selection. Most companies just make two grinds and as far as I know only the ALFA Macchine or ITW/AMP companies make four grinds.

When using v-nails in MDF mouldings you must be aware that MDF mouldings do have a ‘grain’. Imagine the mouldings made from a flat sheet of 1” MDF and the flat part of a 4ft x 8 ft sheet is what you are driving the nail into. In that case you need to use a MDF nail since the wood is extra hard and the top and bottom of the MDF seems to have a ‘skin’ that the nail must penetrate first. MDF v-nails are the dullest grind.’

If an MDF moulding is made by cutting strips off the large MDF sheet and then rotating the cut strips 90 degrees then the MDF must be joined with a sharp or medium v-nail. MDF on it’s edge is like softwood and hardwood nails tend to split the material apart. When on it edge the MDF seems to have layers of material that easily split apart.

The different grinds of nails can be easily seen with a 10 power jewellers glass or loupe.

As for using the wrong nail I would suggest when you open up a box you take a fine point sharpie marker and put a XS, M, H or MDF on the nails at the end you consume ‘last’ Or if you only use two type of nails put a dark line on just one type from one end to the other on all the strips when you open up a box. This will distinguish between the two types you are using. Most nail companies use different coloured glues on the top of the v-nails to differentiate the type of nails. It sounds like you are using nails of different types but with the same colour of glue on the top.

Alan Sturgess

[Larry Peterson]

Thanks Alan for the great info.

I've printed out your answer for reference and now that you have explained the difference, I can see it with my loupe. The difference between the medium and hard is subtle but there. As a woodworker, I should have realized about the blunt ends, but I'm used to drilling hard woods before nailing or screwing (mostly screwing) so it didn't register.

The glue on my ITW nails is the same color for both but all are now marked with a sharpie. Great Tip.

[Frank Larson]

Well, at least I wasn't ALL wrong!

[Jerry Ervin]

Believe it or not, I am using just one type nail in 2 sizes. 7 and 10. The manufacturer claims that they work on any wood type. So far, they have not lied to me. They drive in Ash as good as the cheap Chinese stuff that we really don't know what it is. I have been using them for 2 months. They are new on the market.

If they continue to work as stated, I will only have to stock 2 part numbers. One for 7mm and one for 10mm.

Jerry

[Larry Peterson]

My ITW 10mm mediums don't do well at all in really hard wood. I have some very hard oak molding and another of undetermined species (Decor 6314) that I use a lot of and when I forget to change the nails, the medium 10mm nails only go in about 7 mm sending me over to my disk sander to grind off the proud 3mm.

Withn the oak especially, I have had the medium nails turn (as Alan describes above) and exit the side.

[ 07-17-2003, 12:24 AM: Message edited by: Larry Peterson ]

[Alan Sturgess]

Larry - the mediums usually will go all the way in, but you won't get the best join. Are you sure you are getting enough air pressure from your compressor. A nail sticking out is a sign that you are not getting enough pressure. Also some people are not aware that some compressors drop down to as low as 60 psi before the compressor kicks back on to build up the pressure - most compressors have an adjustment to raise or lower this kick in level. On very hard woods try putting the pressure up to 90 or 100 psi and see if that makes a difference.

Alan

[Jerry Ervin]

The nail sticking out could also be a sign of the moulding moving under the clamp. Maybe you need more clamp pressure.

Jerry