glass

For laying up fiberglass laminate?

Aeropoxy PR2032/PH3660 is best, if you're patient, but you have to order it (Shadow and Aircraft Spruce carry it) and it takes a long time to harden unless you heat-cure it... "Marine" epoxies such as West, System 3, or TAP may be available locally from over-the-counter sources, may be a little cheaper, and the turnaround time on room-temperature-cured layups can be a lot faster... the Aeropoxy stuff is about 24 hours to full initial cure (i.e., not sticky or flexible), while TAP "marine grade" with "fast" hardener takes about 6 hours or so.

For laying up glass cloth (especially fine glass like

1.8 or 3.5 oz. that I prefer) the Aeropoxy is still my favorite because it has low viscosity and wets the cloth so very easily and efficiently.

-dave w

I've compared West/Aeropoxy/No name epoxies, and it seems to me that Aeropoxy is cheapest, and just as good as west.

The simple answer for epoxy *or* CA type glues is that anything found at a home improvement, grocery, mass market, or other such store is GARBAGE.

Hobby and specialty (boat building) stores tend to stock some better varieties.

Another easy give-away for low quality epoxy is a 50:50 mix ratio. This is an indication that fillers have been added to one or both components.

Especially when doing glass layup, you need low viscosity (almost water-like) resin with long curing times.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I regularly use _a few drops_ of denatured alcohol in my "cheap" finshing epoxy when I need to put a layer of 1.5 ounce glass on the center or dihedral joint of model sailplane wings for reinforcement. You can significantly cut the viscosity so it it is easier to get it wet without adding a lot of weight. The alcohol then evaporates and leaves the epoxy to cure.

If you have really slow epoxy, a coupla seconds in the microwave will speed cure and temporarily thin the epoxy as well, though I would probably not use both heat and alcohol together together (the notable exception is while drinking beer and working on a model)

As my experienced (old) friend says - glue weighs one ounce in the cup and three ounces on the plane. The moral is to use as little as gets the job done, and no more.

Feel free to substitute "rocket" for plane anywhere it is mentioned.

FWIW.

BTW, the sailplane guys have gotten into the habit of using +/- 45 degree orientation of the strands when glassing wings. Kinda makes sense in that all of the fibers are contributing instead of just the ones in the right orientation. It also prevents fraying the edges when you cut and handle it. The only downside is that all of the pieces you buy come cut on the 90's instead of the 45's.