Scott,
The 6 mil thick stock of nylon film they offer in the kit is superior for this type of work. Nylon is several times stronger and stiffer than polyethylene bag material and conforms better on flat surfaces such as wings. However, the polyethylene is better when laminating fuselages since it conforms to the shape better. You should be able to buy nylon film from various sources
I like the granite table top you show. For wing lamination where the husks are doing the laminating, it's the best arrangement you can have. I use plate glass....same difference
If epoxy (or other adhesive) is applied to the foam first, the foam will soak it up like a sponge. I don't do it that way. The balsa is first sealed with plain jane hairspray and after a couple hours drying time, I apply epoxy directly to the balsa. A typical 500 sq in panel (top and bottom sheets) will take around 1 oz total. A cheapie sponge roller works well to distribute evenly but lightly. You should barely feel the epoxy after you are done...practically dry but its there. Bagging really puts the load on it so the epoxy comes back out. Must treat the foam with a tack rag to remove any dust
Did you remember to install the tube in the socket when forming the wing mount with subspars? The tube serves as mold to the socket. Subspars extended a couple inches past the end of the socket? Also, did you add 4" square 1 oz glass cloth top and bottom where the socket ends? That's to redistribute the stress riser at the end of the socket.
The aileron cutout facing in the wing, should be extended in a couple inches towards the root. Again to eliminate the stress riser at the inboard side of the cutout. I've seen panels crack over time at the aileron cutout.
I started using 1/4"x1/8" carbon tubing as the aileron horn mount several years ago and have been very pleased with the result. The hole for the horn is already there and perfectly aligned. I use 6-32 bolts for horns (normally not the hardened variety); never use all-thread in this critical application. Vibration will fatigue all thread. If electric power, then not a problem.
Matt
ORIGINAL: Scott Smith
Great info Matt, thanks! (Did you notice I incorporated your vertical webs on the wing socket? Haven't given up entirely on the false rib though!)
My experiment didn't go so well. The cores absorbed the resin like a sponge! I never had time to remove excess. The toilet paper did not pull any resin from the core. 54 grams of glue on one panel [:@] This puts me at 10 oz before LE and caps; workable, but disappointing.
This time around, I pinned the wing to the shuck through the root and tip once everything was lined up. This made it easy to get the vacuum setup and not worry about anything shifting.
For bagging material, I used 4mil plastic. At one point, I let the vacuum get a little excessive and pop! The bag failed at the wing socket. Nice safety valve! A piece of duct tape and I was back in business. 6 in Hg is where I left it to cure.
When bagging "to the table", make sure you have plenty of bagging material draping the assembly. If not, the excess sheeting overhanging the core will get folded over. I knew this from prior experiences and so I tape the perimeter of the sheeting to reinforce. I still had a few spots where the L/E skin folded, but it trimmed up fine.
This was the first and last time I'll use epoxy for sheeting...poly just works better (at least for me!)