Help! My clench nailing is a mess!

[ChuckG]

I've reviewed what I can find online here, as well as some good instructions posted at www.faeringdesigninc.com. (http://www.faeringdesigninc.com.) I even bought a proper clenching iron (although it's not bronze).

I'm using 7/8ths copper tacks in 5/16ths planking (lapped, of course, so the total depth is close to 5/8ths). The results are inconsistent at best. The worst is when the nail crumples over on itself, sometimes it just bends 90 degrees and lays there, and, once in a great while, the point curves back into the wood and it looks like I imagine it should.

Critical variables seem to include the exact angle the iron is at when the nail first hits it, even though I'm tapping pretty softly, and to have the iron right there BEFORE the nail emerges from the wood. But that is pretty hard to control when you're reaching up under a lapped plank and doing all this by braile.

I've been told that polishing the iron may help. I've practiced on the bench until I get several in a row that look ok, then I go to the boat and they look as funky as before.

I'm considering switching to screws, half way thru the planking job. Does any body have any suggestions or thoughts?

Thanks,
:confused:

[imported_Steven Bauer]

Screws won't work in such thin planking. But rivets would. :D But I think you should get a helper. Is there someone you could bribe or coerce somehow into helping? I did mine by myself but the boat was very small and I could hold the clenching iron with one hand and drive the nail with the other. The key is to hold that iron on the inside really, really tightly. Keep us posted. Oh yeah, whatcha building? Got any pics?

Steven

[Mike Vogdes]

Chuck,
Although I have never done this type of construction, I am under the impression its a two person job. One person holding the iron firmly in place, the other person driving the nails.

[Paul Scheuer]

WB had a real good explanation. I'll see if I can find it.

What I found is that most instructions don't include troubleshooting.

I found in my practice, that when I tried to overpower the situation, I got crumpled nails in the wood and poor curling. I'll suggest that you lighten up on the hammer. I use a very light tack hammer and many light taps on clench nails and for heading rivets.

(Just between us, ok, if I didn't get an acceptable curl on occasion, I turned the point with a needle nose pliers.)

[Paul Scheuer]

How 'bout that, I knew I'd seen it somewhere. Issue 174, Sep/Oct 03.

There's also a short piece in issue 26 that shows the alternative method of turning the point of a seated nail. It might be easier to control the curl with it out in the open.

[Mike Field]

... if I didn't get an acceptable curl on occasion, I turned the point with a needle nose pliers.Ha. My thoughts exactly. Drive the tack (a longer one if necessary) right through both planks, turn the point over a bit more than 90° with needle-nosed pliers, then tap it right over into the wood with a dolly on the head to hold all firm while you do it.
.

[Dave Hadfield]

Your clenching iron has a slightly curved surface, right? I think you want to hold the iron off-center a bit, so that you get the end of the tack bending in the right direction. Once that is accomplished, then center the iron to clench the wood layers together.

Think of the pride you'll possess when you get the knack of it!

[ChuckG]

Thanks for the words of advice and encouragement!
A summary of what I've learned (in addition ot the obvious "how-to"):

1. hold the iron TIGHT to the inside of the plank. It does seem to be critical that the iron be right there for when the tack/nail point FIRST emerges from the pilot hole.
2. Many small taps, with a lighter hammer. I've been using a small claw hammer (8oz?), but will try a smaller tack hammer. Compare this process to riveting, rather than driving a nail.
3. A polished iron. Any rugosities in the surface will catch the point, especially right at first.
4. The position of the iron is critical. The angle at which the point first hits the iron sets up the rest.
5. Drilling the pilot hole at a slightly acute angle to the face of the (outside) plank will help establish that critical angle of "first strike."

So, how to fix up what I've already got? For the tacks that simply folded over at 90 degrees and are laying flat on the plank, I think picking at it with a needle-nose pliers, and lifting it up enough to roll the point over some more and then re-seating it into the plank might work. I think the crumpled nails are probably best just left alone, perhaps backing them up with another nearby nail (being careful not to split the wood). And some might be repaired by center-punching the head, drilling it off, and driving the nail on thru the inside. But that sounds as if it might leave a bigger hole and problem than a less-than-optimal clench. I'll have to evaluate on a case-by-case basis, I guess.

Any remarks or experience about repairing clench nails?

(I'm building a model of Catherine, from Rich Kolin's book, Building Catherine, Traditional Boatbuilding Made Easy [HA!]. It's a fourteen and a half foot lapstrake Whitehall wannabe, with daggerboard case and sprits'l. Pix to come)

Thanks again folks,

[Ian McColgin]

I don't know anyone who can drive clench nails from the outside and turn them in one operation without a helper. The person handling the iron needs to handle it accuratly and this seems to require seeing what s/he's doing.

The dodge of using pliars to start the turn and then working from the inside while you hold the clenching iron (or anything heavy) on the outside takes more than twice as long but is about the only way to have good enough control.

You might speed things a little if you have a second iron that's got a nice target hole, maybe 1" diameter, so you can easily tap the nail homme before you get under. Also, if you've good clamps, you can pretty much tap a bunch of nails in from the outside before going under.

Make a comfortable stool on casters.

G'luck

[Don Olney]

Chuck,

The current issue of WoodenBoat (#174 pages 62-64) has a good article by Harry Bryan on clench nailing.

It takes a little practice. But, even when you get better at it, be prepared for a few nails that go bonkers every so often. Just snip the end off, extract the rest and try again.

Take a look at each nail before you use it. Many of them will be curved slightly. Use that to your advantage by placing it in the pilot hole so that the natural curve is facing in the direction that you want it to bend.

As with Steven's boat, mine was small enough so that I could drive the nail on one side and hold the iron on the other. In this case, the "iron" was another hammer, which worked fine for me once I got the hang of it.

-Don-