im on my first scratch build, (cessna L-19) and want input on glues and lite ply cutting methods on the inside of formers and such, im using a plunge roto -zip and dont like the amount of clean-up time after using this tool. also im wondering about using a wood type ca as opposed to gorilla glue that is wonderfully strong but takes alot longer to set up. what are you guys doin? thanx Ted aka flip-flop-fly!![8D]

As a basic rule of thumb I avoid light ply for various reasons, but I do use it on ocassion. From my experience....

Cutting light ply. Plung router works fine. I have a CNC bed that basically uses a plunge router to cut out parts. Works fine with light ply. I would however suggest getting a good carbide Dremel bit (or similar) instead of the standard side cut plunge bits. The fine tooth carbide bits leave cleaner edges in light ply.

As for glue, I've never had real good success with CA and light ply. It works, but the light ply sometimes won't stick well with CA and I end up making big filets of glue to hold stuff together. The poly glues work well. Instead of Gorilla Glue (poly), look for Elmers ProBond Poly glue... same stuff but typically cheaper. Other glues/adhesives like epoxy, alphatic rosins (wood glue like titebond), etc will work. If you are looking for speed, low weight and strenght, maybe you can tack with CA and form a very small fillet with poly glue.

Primarily my glue consists of.
Thin CA
5 min epoxy
Gorilla glue (when current bottle is empty I'm goin after the elmers poly)
You could build a school with just those three.
I do use Sigment for fillets and such at times.

I use a combination of Medium CA and carpenters glue. For example, take a cap strip, a drop of CA on each end, and one in the middle, then wood glue on the rest. The CA holds right away, so pinning is not necessary, and it holds it until the other glue dries.

It's quick and cheap.

Carpenters glue (alphatic resin) is my glue of choice for 95% of the building. I steer away from 5 minute epoxies with a pasion (they are much weaker than the slower curing glues and I have seen many poor joints by people using it). A good 30 minute epoxy has its uses as does CA. If you must use CA on lite ply (or any hardwood), lightly dust the area to be glued with plain old baking soda first--a very light dusting--and the CA will work reasonably well.

thanx abig ole bunch to John W, Crashdafew, Rodney and Minnflyer for your most exellent advice. definetly must pick up a few more dremel attachments, man, they make the coolest gadjets for us dont they? you know that gorilla glue is pretty pricey, so finding out bout that Elmers poly is a 10-4. also thanx for the tip bout the little dab of ca and then using the other for the rest, quick and strong!! wish you all lots of sucsess with your projects this winter and good flying!! man i love this "universe" of ours!!!! later, Ted aka flip-flop-fly!

I had to do a rebuild after a crash. Tried various tools to cut lite-ply. Finally settled on a scroll-saw, and a power sander.

Use scroll saw to cut piece slightly too big. Use various convenient sanders to grind the piece to the final shape. For tight inside corners, I found that the small round file in my "hobby files" pack fitted really well in the chuck of my drill, and is a good tool for those tight places.

For what it's worth, I had an interesting insiht when re-building the firewall. The original kit had two pieces of die-cut ply glued together. for the rebuild, I cut blanks for the firewall that were intentioally too large. Epoxied together, and then set the bevel angle of my scroll saw to 3 degrees (the required right thrust), and cut the firewall at the right angle, instead of the "stepped" pieces from the original kit.

gus