Thomas Stender
Posts: 18
Joined: 2003-07-06
Location: NY
 User Profile |
Randy,
I don't know what you mean by "interior & exterior wall" but if you're building two frame molds similar to that in the photo on this site, you're on the right track. Check the fairness of your molds with a stiff batten or a long strip of plywood, making sure that all the studs in the mold just touch the batten without pushing it away from neighboring studs. Have a good plan and a reinforced area to clamp to at the ends of the stringer, because it's hardest to maintain a fair bend at the ends of the material. Better to extend the mold and cut the stringer to fit. In theory you need only two clamps with big cauls, but it would be worthwhile to have a continuous caul that's not too bendy so that you can easily put clamps where you need them. I use epoxy for these large curved jobs, with some colloidal silica to thicken the mix a little. Colloidal Silica is slipperier than microfibers, for instance. The filler helps keep some of the epoxy in the joint instead of sucking into the wood. Apply only enough pressure initially to pull the sandwich together. Once it's in place on the mold, and touching all the studs, increase the pressure. Then friction between the layers is enough to hold the form. I would advise using the air evacuation mesh on the caul side of the stringer. And that brings up another point: don't exert any more force than you need with your clamps. They can easily distort the form. So take a careful look at the layup before you go for coffee, making sure that the curves are fair. Look along the corners of the sandwich for hills and valleys in the curve. Good luck.
Tom
|
