[JohnB]

I have done these a couple of different ways, and until I see or hear something different, this is how I did mine. I used epoxy, it has a lot longer working time, especially the slow stuff than glass.

Test fit the core, and level out any "dips" in the skin with thickened epoxy paste.

I would coat the coring material with the epoxy, lay it flat, and let it cure one day. With the plywood, I had to do this a couple of times, because it soaked up all the epoxy.

Then I would take and lightly scuff it, and wipe it clean.

Then I made an epoxy paste thicken with milled wood flour the consistancy of thin peanut butter, and trowled it on the skin, with a notched 3/8ths inch trowl. put the core against it, and clamp it in, but not too tightly, just so it starts oozing evenly out the sides.

I used 2 layer coring, so I repeated the process for the second core, but went with a thinner layer of epoxy between them.

Then I put 4 layers of 1708 on the inside, all with epoxy. If I was going to all the expense of using coosa, I would use epoxy. Unless your vacuum bagging the coosa, it is hard to get a real good bite with poly into coosa. Epoxy has a much stronger adheasion. If cost was the determinate, I would use good marine plywood, and poly glass. I don't think I would use poly with composite in a transom rebuild in the back yard. I am not saying it can't be done, and hasn't been done successfully, I just saying there is less room for error.

I did mine myself, I would suggest getting a second set of hands sticky.