pin nails holding power (ref: to Norm as well)

[Renata]

You know how Norm is always shooting a "couple" nails in until the glue sets up...?

I am wondering how well those little teeny pin nails (ala Grex) work as pseudo clamps until the glue sets up when attaching part a to part b (say plywood pieces) w/glue.

IOW, do the pins merely serve to hold the item in place and have virtually no clamping force (due to their size and lack of a head)?

I have a piece that will form a 45 degree angle when attached to a

3/4" ply edge that won't have any real force acting on them (merely decorative) and I don't feel like going to the trouble of biscuits or dowels. Clamping is difficult due to the angle (though I could whip up a jig if needed, I suppose). So, I figure I'll just glue 'em up, and shoot some pins/nails "until the glue sets up".

Anyway, is this enough, do y'all think, or should I at least use real clamps (w/a jig or such)?

So many words for such a simple question....

Thanx Renata

[John B]

G'day Renata, The pins should hold fine. Clamps should only be used to hold a piece in place until the glue dries. That is all things being equal and a perfect world where nothing bowed or needs a little extra pressure to close a joint :)

Most pins used by air guns are coated and once shot into the timber are almost impossible to remove without breaking them.

When I first started cabinet making we used hand pin trim in place then putty and polish. Sometimes we'd even pin the piece leaving a few millimetres of the pin proud of the surface so that once the glue had dried we could pull the pin and not have the punch and head hole to fill.

A short answer yes :)

regards John

[Leon]

To add to John's correct comments, absolutely, the pins are strong enough and have enough holding power to hold pieces together until the glue dries. I think however that Norm is actually using brads rather than pins, I could be wrong. Naturally the brads will hold a bit better than pins.

If your surfaces are "correctly matched and machined", masking tape has plenty of holding power. Clamps simply hold joints that need to be moved and insure a better fitting joint when working with less than perfectly prepared stock.

As John has indicated, it is difficult to remove a pin with out breaking it. All things being relative and for it's size the pin probably holds just as well as a finishing nail. Another trick is to simply shoot the pins at different angles along the joint. This adds to the resistance for the joint to pull back apart.

Again as John has indicated most all pneumatic nails that are glued together like pins, brads, and finish nails make use of that adhesive to hold them in place when shot into the lumber. I have experimented with the holding power of 3, 3/4" long pins through 1/4" plywood into 3/4" plywood. The union was strong considering the size of the pins. More than expected effort was required to pull the 2 pieces apart. No glue was used.

Keep in consideration also that a glued joint reinforced with pins will be pretty strong after 30 minutes or so.

[charlie]

rubber bands. strap clamps, putting the phone book on top of it, etc all work well as temporary clamps.

[SonomaProducts.com]

You need to be a bit careful here. Using a Polyvinyl Acetate glue adding a few hundred pounds of clamping pressure does result in a much stronger joint at the maiting of the clamped surfaces if left in place until the glue is mostly dry. Depending on the joint type this can make a big difference.

For instance, in a mortise and tennon it doesn't matter much because you can't clamp the mating surfaces per-se, so you just clamp to keep the pieces where you want them, but if I am gluing a 2x4 to a piece of ply the clamping pressure will add much to the strength of the joint. So the real question is how much force can the nails\pins\brads add to the joint when you need clamping pressure. I would guess that a well placed brad or pin would add 100 pounds or so if left undisturbed. But the force probably diminishes as you move away from the clamped location pretty quickly because the force is so localized to a single point.

Have you ever seen a panel clamping force diagram? From the face of each clamp, the full force is dsitributed at a 45 degree angle from each edge of the clamping head. Outside the 45 degree angle the force dimishes (by the square of the distance I think) So wider boards don't need as many clamps to have the same force across all the joints as thinner (non-intuitive). In reality most clamps will be set to 300-400 pounds so the 100-200 you really need is distributed outside of the 90 degree splay.

[Nova]

I've seldom seen Norm use a "pin nailer". His normal comment is "A few brads..."

[Leon]

As I had indicated earlier, a properly matched and machined gluing surface is needed for the glue to adhere properly. 2x4 stock is very seldom flat or smooth enough to be glued with out clamps. You will get a better joint with construction lumber if you clamp before screwing, glue or no glue. Clamps simply keep things together and help to eliminate the gap if the surfaces do not have parallel planes. As for your mortise and tennon example, well that is an excellent example of a strong joint that does not need much clamp pressure to make the joint strong and secure, including those made with floating tennons in over sized length mortises.

[Leuf]

If the piece being attached is small, or you can support them to remove gravity from the equation, often you can just glue it and that's it. It helps if you spread the glue out into an even thin layer first, it gets tacky really fast and instead of the piece sliding around on top of the glue it literally just sucks right on. Also pulling the pieces apart and then right back together seems to help with this for some reason. Be a human clamp for a minute or two and then walk away. This assumes that the surfaces mate well of couse. Screwing around with a nail gun is just looking for an excuse for the thing to slip out of alignment right as you press the trigger.

-Leuf

[Renata]

Geeze! Would you guys stop being so literal. :-) It's the concept not the details. Brads leave (relatively) big holes and pins leave teeny holes. Used brads til I got meself a pin nailer.

Forget pulling the pins out, BTW ('nother post). They break off at any such attempt.

Thanx for all the responses.

Renata