Good morning Swaylocks community. I'm onto my second board, a hollow board of my own design - Paul Jensen method of wood on frame. The design is intended to be a nice docile learners board for my daughter.(and it looks great with a dolphin set in the middle of the deck...) It will be a thruster and yes, I'm making my own fins!!
I was obviously not paying the right sort of attention when I put the base skin on and have got a warp at the end of the board. I am up to the stage of putting the fins on and would appreciate some ideas.
The warp looks to me like it will cause the right side of the rail to drag more than the left. I'm figuring it will turn right better than left. I'm not partuicularly concerned about the performance from that point of view. I am interested to know if I could moderate the amount of turn caused by the warp by compensating with the offset of the outside fins.
I submit my design oppurtunity to you all and would welcome your input.
Cheers Mark
I would not recommend trying to compensate for warp by installing fins in other than their correct orientation.
You may not have evenly supported the board when attaching the skin. If this was the case, think of removing the skin and re-applying it. A thin very sharp flexible blade Japanese style saw which cuts on the pull stroke may be the best tool to remove the skin.
Warp generally comes from wood that is not the correct dryness (moisture content). Wood shrinks when drying, and usually one side or edge of a stick dries and shrinks more than the others, inducing warp, twist or check. Warp can also come from wood that has internal stresses that are released only when the wood is sawn to smaller pieces which are less able to hold their position. Either way, warp is a result of stress, which induces strain (engineering terms, but that's where I'm from).
You can try mist wetting the board or steaming it, then drying it under stress to reduce or eliminate the warp. It's time-consuming, and its trial and error, but I see no other way.
I don't think you could stress it straight, glass it, then release the stress and hope it stays straight. You'll have to deal with the warp before proceeding to the next step in your build.
Thanks for that Charlie. Like engineering terms - I spend a lot of my time in that arena as well. Unfortunately the board is already glassed so I think I will proceed with fin installation. Worst comes to the worst, I get to build another board and have a peice of eye candy for the wall!!
I had the frame sitting aside for a time (in my very dry garage) so it was really dry. I suspect I managed to flex the frame when I put the skin on. Most importantly, I will put the fins on in the correct alignment.
Thanks again, Mark
Have now taken it out a couple of times. Seems to be okay so now it’s up to my girl to learn how to ride!!
Cheers Mark