filling holes when refastening

[Paul Silverman]

I'm spending May and June finishing refastening my 65 year old cutter, "Kelpie" (William garden). She is cedar on oak, originally fastened with iron nails and a few screws at butt blocks. We're pulling each nail, soaking the hole in thinned epoxy, filling with epoxy and wood doweling, then redrilling for silcon bronze screws. My anxiety level is rising as we are nearing putting her in the water for the summer sailing season here in Montana (Flathead Lake). I am starting to wonder whether we are doing as much damage as good. I'm finding that I am replacing some of the butt blocks that fall apart as we extract screws. My biggest worry is as follows, and I would appreciate some comments: Many of the screws that were used to fasten to butt blocks have deteriorated to the extent that the only way to remove them has been to chisel around them a small hole that is virtually the depth of the cedar planking (4/4). I am filling these holes with thickened epoxy on the assumption that the epoxy will be an adequate structural replacement for the cedar, then drill through the epoxy and into the frames for the new screws,which will then be bunged. Drilling new holes in the undamaged wood is not much of an option as the boat is relatively small (25 feet on deck) and the frames are narrow. Will the new screws hold? The boat originally was in salt water year round in Port Townsend, Washington. The new life (for the past three seasons) is in fresh water for 5 months of the year, then drying out on the hard.

[RGM]

Great skiing over there at Big Mountain, really like that place. I know of the boat. I was wondering where it went. You have yourself an interesting situation. Kind of like a fish out of water. It's really a boat that doesn't belong on Flathead Lake at all, especially on the hard during Montana winters, no offense. I remember changing out a fuel pump in the ski area parking lot one night when it was 30 degrees below zero. It was hard to keep the metal from sticking to my fingers. It can be a tough place for a wood boat. What the boat really needs, excuse me, probably needs, is to be re-planked and re-framed (and probably returned to Puget sound). As you have stated, it's a small boat. There really isn't alot of material involved and Flat Head Lake is actually pretty close to wood boat building suppliers. Going the epoxy route (as deep as the planks are thick at the butts?) is not a good solution. Epoxy is not water proof. It won't bond well to cedar planking that has "nail sickness". Re-fastening in silicon bronze is not a good idea because that money would be better spent on new frames, new planking material, new butt blocks or transport back to Puget Sound. Galvanized screws last one hell of a long time in cold fresh water. Besides, the rest of the boat is fastened with iron. Now, for what it's worth, you will be mixing metals. I imagine that you've already purchased all the bronze fasteners? Sounds like you are driving these into "wood dowels" that have been glued into the itty bitty frames? What material are these dowels made of? You are wondering if you are doing as much harm as good. I would have to say yes. However, I would also have to ask, who advised you to take such a path? Did some "expert" direct you or did you decide to take this path on your own? I don't mean to sound like a jerk, but your concern is well founded and you did ask for input. Good luck.

[Paul Silverman]

Well, the advice is not whatI wanted to hear, but I do appreciate it, RGM. I don't think I need to worry much about mixing metals, because I have been able to get all the ferous metal fasteners out- and am actually nearing the end of the project below the water line. I know the drying out is not good for this boat, but she's done well over the last three seasons. I switched to bronze because I do anticipate returning her to Puget Sound some day. Iron rot doesnt seem to be a problem- the frames and planks are in good condition. My key question at this time, is whether the epoxy and thickener can be used as a structural substitute for small portions of wood as far as holding fasteners over the long term. If I recall, the Gougeon brothers indicate that it can. For example, they have described an application in which machine screws can replace wood screws by drilling a hole, filling with epoxy, and essentially taping for a machine screw, and then using this.

[Dan Hobson]

Hi, I'm just spit balling here, but I've seen similar things described in wooden boat magazines all my life. I think one of the things you want to do is view the situation with an eye to the mechanical properties of the shape of the plug. When the boat goes back into the water the wood around the plastic plug will swell up. If the plastic plug you have placed in the wood has the cross sectional shape of a thimble, with a lip at either end, there is less chance of it ever moving for any reason. And what's more you spread the load over a much larger circle of material than with a nail or a screw. So it should stand up pretty well. If the plastic plug has a conical shape, the wood swelling up can tend to push the cone out of it's hole. And this would generally be regarded as a bad thing. But even this might not be so bad if the fastening is a rivet or through bolt into a frame. The glue bond chemistry is one thing. Over time the glue may or may not stick to the wood. But the hard plastic plug created in this process should be of a shape engineered to stay put regardless of the glue bond. You got your self a wooden boat so you might as well learn to love working on it. The real story on these things is that nothing stands the test of time. Your work might take this boat beyond your life time, but it's eventually necessary to do these things again for one reason or another with just about all of them. As well, when you fill a hole with hard plastic, and then you put a screw through that you are isolateing the metal from the wood. That should work for you in the long run. I think that your basic method can be applied in a sound manner. Good luck