Damming a mold?

[SOB]

What is involved in damming a mold in a v bottom with full length strakes. Can a insert be installed to achieve shorter lengths without damaging the mold?

[wet feet]

If you intend to move a flat transom forward to reduce the length of the hull,it is not too large a job.Once you have determined the location of the new transom,you can cover the mould surface aft of that point with a protective film or heavy paper or multilple strips of duct tape or whatever you may prefer.You then fit a pair of sturdy straight edges across the mould and use a good dollop of polyester filler or similar to hold them in place.It may be that they will need to be raked to accommodate the angle of an outboard,if that is the propulsion you intend to use.Fit a sheet or sheets of melamine faced board to the hull mould as accurately as you can.You may find it more convenient to use offcuts for the strakes.It may be best to run a fillet radius of Plasticene around the edge of the transom to avoid a fragile sharp corner.Coat the new surfaces with release agent and you should be ready to go.Having produced a shorter hull,you will then need to determine how to reposition the masses within it in order to make it trim properly.

[SamSam]

Originally Posted by SOB

What is involved in damming a mold in a v bottom with full length strakes. Can a insert be installed to achieve shorter lengths without damaging the mold?

If the transom has detail, convolutions, etc. that you want to reproduce, you can splash a temporary transom mold off a completed boat and fit it to the mold or if you have no completed boat you can lay up just the transom in the mold, take that out and then splash a temporary transom mold from it and then fit that to the mold. A few L-brackets can be screwed to the inside of the mold to hold the temporary mold in place, when you are done the holes can be plugged with Bondo or something and then waxed over, they won't be noticable in subsequent hulls. Not a whole lot of attachments are needed, just be carefull when rolling and working the first few layers of glass to not shift anything, after a few laminations it sort of self supports. Although it doesn't take much support for laminating, if you have to use heavy clamps for installing a plywood core, you have to take that into consideration. You can radius the corners with modeling clay stuck in them and then formed with a waxed socket wrench socket of the appropriate radius pulled along the corners. Sam