I’m at the point where I have my hollow wood frame built up and ready to receive the top and bottom skins. The skin has been built up out of 5mm thick spruce, laminated on the inside with a thin cloth and epoxy for added strength.
Now I am wondering if I can use expanding PU glue (you guys seem to call it Gorilla Glue?!?) to glue the skins to the frame… because I like the idea of added strength due to the expansion of the glue.
Will the epoxy/pu-combination provide a good, long-lasting bond? An alternative I have in mind is to use epoxy thickened with micro-balloons. The extra thickness is needed given my sloppy woodwork skills and the epoxy/micro-balloon mixture is supposed to stay somewhat flexible…
Dont even think about useing PU glue to glue your skins to the frame. It has no strengh at all and will fail just from expansion and contraction from temperature changes.West systems 105-206 with 406 silica or beter yet West systems Six 10. The Six 10 is easy because it is in a calking gun with mixing nozzle, Run a bead allong the ribs and set your skins on be sure not to slide the skins around and smear off the epoxy. Do a couple dry runs first. Make sure you have a couple tubes of Six 10 on hand cause if you run out in the middle of the job your screwed. Theres not as much epoxy in that tube as it looks because it is 1-3 mix part of the tue is just air.Yes, Six 10 is expensive ! But you get what you pay for !!
I second that you should not use Gorilla Glue. Aside from the structural issues that Wood Ogre brought up, the joint will also look ugly. Epoxy will look much better after you glass the board since it will be almost clear.
I’ve had good success with RR epoxy mixed with fine sawdust (your palm or random orbit sander is a good source) and fine chopped glass…stick it in a ziplock bag, cut out a small bit of a corner of the bag, and then caulk it on. Not as convenient as a caulking gun, but since you already have epoxy on hand, it works out pretty well. Plus, if you run out mid board, you can always mix up some more and add it to the bag (or just start a new bag)