Tack Depth

K90

Curious about Wooden Canoes
I am in the process of building my first boat. I have recently completed clinching the hull and was in the process of faring in preparation for canvas. My question is about tack depth because it seems that I have driven some/most of the tacks too deep. After I soaked the hull, the hammer blossoms all came out but about 60% of the tacks now have a depression around the tack head between 0.5 and .0.75" in diameter and roughly 1/16" deep. It is too late to do anything about that now, but my question is about filling these gaps - should I fill them all in and then fair and sand the hull, or will that size hole be spanned by the canvas and not require any further action? If the answer is fill them in, any suggestions as to what type of wood filler to use?
 
It's far better that the tack heads be below the surface than proud. There should be no need to fill those depressions as they will not show once the canvas is on. On the other hand proud tack heads will show through and cause problems when you are applying finish.
 
Great, thank you for your reply Andy. There is no concern that over time the canvas will stretch into that depression under full load and make the canvas loose in those areas?
 
I thought I would add a picture, this is one of the worst areas where I have actually damaged the planking, but still the depressions range from 0.5 - 0.75" in diameter and 1/16" deep. No need to fill in these type depressions? It certainly will save a bunch of time if I can skip it.
IMG_1257.jpg
 
Holy mackerel....that's some serious hammering. It's rare to actually break the wood fibers around a tack like that. You might want to take a look at that hammer and see if you can soften the edges.
I would not fill those....they will vanish under the canvas. If you are really worried about it take your steam iron and a damp towel and stem the wood back up to the fill the dimples. Personally I loath digging filler (or resin) out of tack holes in order to work on a boat so except for really bad imperfections I try to avoid adding glop when I fare.
 
Yea, I might have gotten a little carried away with the hammer. I used plenty of water in the planking process to get the boards to cooperate so they were pretty soft. I am in CO, and if i don't use lots of water the planking tends to split along the bilge due to the low humidity (I'm assuming).

I'll try the steam and no filler. I really appreciate both of your responses, thank you very much!
 
Get yourself a cobbler's hammer. They are cheap at flea markets or on eBay. They have a nice, wide head that is domed. Perfect for setting canoe tacks without leaving much of a hammer blossom.
 
I will get a cobbler’s hammer before my next build, without a doubt. Thank you.

The ironing worked well to lift up the wood fibers. Thank you all for your help.
 
I'd give you my cobbler's hammer but I like it too much. My hammering usually looks like your photo but the cobbler's hammer makes me look good. I'm in Aurora so my planking was under similar conditions.

IMGC2030 by Dave, on Flickr
 
Thanks Dave! I’m in south Denver.

It seems that I should have come to this forum a long time ago. Certainly a wealth of knowledge.
 
Awesome, another Denver paddler, I'll be in touch, for sure! Some procedural advice now that I am about to start the finishing process would certainly be welcome.
 
Has anyone ever considered using some sort of a nail set to hammer in the tacks? It would need to be larger than your typical nail set used in finish carpentry. Since the nails/tacks in my canoe have a domed head, I was thinking about making a nail set with a recessed dome like shape in the tip. The only problem that I foresee with this method would be that it would require both hands and you would then need someone on the other side to clinch the nails/tacks.

I would probably hammer the nails/tacks without the set until they were almost at the wood and then use the nail set.

I'm thinking of taking one of my metal punches, cutting it to a diameter slightly larger than the dome of the nail/tack and then use maybe a dremel to scoop out the dome??????
 
Actually a punch about the same size as the tack head works just fine. There is no need to modify it. When I am working on a restoration I always try to re-clinch tacks before I canvas. Sometimes the heads are buried below the planking surface to the point that the only way to give em a ping is to use a punch on the head of the tack. It's a three handed job though. What I do is invite my son and his girlfriend over for dinner, give him some of my best bourbon to loosen him up and then steer him down to the cellar to hold the clinching iron. It needs to be a fine meal to get them to come back. A few NY strips usually do the trick. It also cost me some Parkers last time....
 
Back
Top