Builders' Forum Archives
Posted by Dave Houser on Feb 4, 2005
The advantage of leaving the wires in is less building time, but I am convinced I make up the time by masking.
The The trick to tabs is to mask the outside seam between the holes before you tab on the inside. Don’t thicken the epoxy too much, thinner than mayo, so it settles into the seam. Make a very small radiused fillet to tab between the wires. I use a Popsicle stick to strike off the tabs. It is also possible to just squirt in a small bead of thickened epoxy with a glue syringe. However you do it the tab needs to be smaller than the finished fillet. After the tabbing sets pull the wires. If you get any epoxy on a wire heat the wire and pull it out with pliers while it is hot. Then mask the holes and balance of the seam. Make a deeper wider fillet, using a larger radiused card or stick to strike off the final larger fillet. The small tabs should be completely buried in the larger fillet and they will not snag the larger radiused strike off tool. By masking (and if you don't make the thickened epoxy too thick) the epoxy will fill the holes and cracks without dripping or wetting the outside wood, no filling effort and no sanding off drips will be required on the outside of the hull.
Use a much tighter radius on the fillets where the panels meet at an acute angle (the keel at the bow and stern) than where they meet at an obtuse angle (keel under the seat). I change spreaders, with different radus, along the length of the keel usually at the bulkheads.
The other trick I do when making the larger fillet is to let the fillet soft set (2 hours) before laying down the tape and wetting. The fillets won't squish around and leave finger dimples. The usual method of taping over a wet thickened bead of epoxy is quicker and less effort but not as neat. It’s a matter of esthetics inside the boat.
Inspect the tape when the epoxy sets to flypaper sticky (won't come off on your finger but still is very sticky about 2 hours). Press down any bubbles and that nasty salvage edge, it will stay down in the sticky if you time it right. You can also rewet any dry spots at the same time because the fresh epoxy will still penetrate the sticky.
Another trick to keep stubborn edges down or to eliminate a bubble in a tight inside corner is to cover it with a piece of kitchen plastic wrap before the epoxy kicks and press the air out from under the wrap. You will end up with wrinkles in the epoxy surface from the plastic wrap but the edge or bubble cannot lift because air will not get past the plastic wrap to get under under the glass cloth.
In Response to: Re: Copper sutures by Laszlo on Feb 4, 2005