Hey guys,
Got my form finished this weekend for the Bingham take down bow I am working on. I know I questioned the need for the heat box on another post and several of you guys said I don't need it and I can use my truck to help it to cure or I could just let the smooth on cure in 24 hours at 72 degrees. But I also understand, that if I go ahead and cure it at a higher temp, it may give it more durability to stand up in higher temperatures down the road without delaminating. I think the truck thing is a good idea, but I am beholden by time of when I can do it versus the heat box I can do it when I have time. Basically I think I want to go ahead and build the heat box but I don't want to spend the $180 on the 2 sheets of plywood for Bingham's plans. I have some old lumber that I pulled out of a house that was built in 1840 that I have had sitting around for years. I would have to plane that wood and get it shaped, but the net effect would be that the heat box would not be built with 1 piece of wood per each side. I would have to build it up say with boards that are 6" to 8" wide and on each side. So in effect all the sides bottom/top etc.. will be boards that have to be joined. My thinking was even if I didn't glue the boards up to make that perfect joinery piece in the wood, I could come back and caulk all the seems once the box is finished. If I did it this way, I don't have to outlay any $$$ just a little more time in the build.
So my question to you is - there is nothing magical about the plywood box right? I would think I would have the same effect as long as I caulked all the seems thereby closing any gaps where heat could escape right? Just thought I would double check with you guys before I put the time into planing and ripping these old boards up.
Second question I have is when I watched the Bingham video, they used contact cement and sprayed the top of the bottom mold and the bottom surface of a strip of formica and then glued that formica strip to the bottom mold where the lams will glue up. Well in the video, it was more of a 30 second deal. Spray form, spray formica, then lay the strip in carefully aligning it on the mold. Well when I did it, it didn't work that way at all. The contact cement I used said let it sit for 5 mins until it got sticky and then attach it so I did. However, the bend in the recurve form was just too much for the formica and I sat there trying to work the formica into the curve section and it did not want to stay. The glue held in the straighter section of the mold, but not in the curve at all. I simply could not hold it anywhere without gaps forming between the formica strip and the mold. I fought it for about 5 mins or so and then decided to use the filament tape. I would hold tight a section of it and my wife would wrap it. Then I would move a little further into the curve and we would wrap that too. I went all the way around the curve and let it set for 24 hours. Of course now I had glue chunks all over this smooth piece of formica. In the end I cleaned up all the glue with acetone and it is glued in place with no gaps.
Now that I am thinking about it, do you think since this formica sat in the box in my office for 4 years it stiffened up with time and that is why it was so much harder than what they showed in the video? or is this just normal? or did I do something wrong?
Thanks again for all the help.