Originally Posted by heron237
Nicholson, I don't understand? You formed the rudder out of solid epoxy thickened only with bubbles? I see on inspection
of your picture that you were only filling the voids between the rudder armature it could have filled it with any non reactive foam. Then at least clothed up the skin for impact resistance. And mixed it in seven gallon batches? I mean it's exothermic it didn't bubble up in such a large batch? Doesn't make sense to me. Would you mind clarifying, thanks.
Solid 6 inch thick filled epoxy as noted. Total 30 gallons mixed in two pours. (top section and bottom section) The Us Composites 635 is VERY
slow. It also costs way less than West. You notice no exotherm and no splitting or shrinkage. After 24 hours it is like cold chewing gum. The compressive strength is about 3000 psi. With a carbon skin over the outside it is probably bullet proof. It hammer rings like a bell. (freaked out the surveyor) It is built over the original welded SS armature. The rudder before rebuild
was saturated moldy foam with blisters
. I prefer this system especially below water
to any balsa or foam system since it will never permit
any water in. I built up the steel
with fab-mat and epoxy and faired the surfaces to near the level desired for below the skin. Use an aluminum
straight-edge like a concrete skreed to find the high spots. Rub it lightly over the surface and the glass bead filler turns black from the aluminum
oxide. This shows where to grind. I ahd to add a couple of skin coats to get level. In the end, I had Torresens in Muskegon vacuum bag the carbon fiber. They used West epoxy.
I also use this system to repair my water soaked balsa core
deck sections. Drill into the bottom skin with a hole saw; dig out all wet filler. Keep drilling and digging until you reach dry filler. Let it dry for a while. Repair the skin using 635 and fab mat. The holes will appear as clear windows. Mix 635 and balloons and pump it in to totally fill the void. You can see the resin front through the windows.
It can be sanded, polished and painted.