Glassing wing center
 

Gidday all, I'm at the stage of fiberglassing the center of a wing and I have a choice of 2 resins, Crystic Polyester or Epoxy Resin. What should I use? Thanks in advance for an answer.

Glassing wing center
 

John,
I'd recommend the epoxy resin, especially if you can find the finishing resin as it is very thin. If not, you can thin out regular epoxy by mixing in denatured alcohol. Suggest you use a 30 min, or longer epoxy to allow plenty of working time.

Glassing wing center
 

Either will work fine. Epoxy resin should be a little more flexible, and that is what I use (20 minute finishing or regular 30 minute). Polyester finishing resin should work fine, though, if that is what you already have. Another option is to use thin CyA glue. Great Planes suggests that method in some of their instructions. I have used it to apply fiberglass to the inside of cowls at the screw points, but I've not tried it on a wing joint. Whatever you use, make sure to squeegee it out, so you don't get too much resin under the fiberglass. Keep it thin and tight against the balsa to get a strong bond and no bubbles. If you use CyA glue, use a piece of clear plastic baggie on the tip of your finger to spread the glue.

Pilgrim

Glassing wing center
 

Pilgrim is right, either will do the job. However, a further thought... if you use epoxy to join the wing halfs, then you ought to stay with epoxy for glassing . If you use aliphatic resin to join the wings then epoxy or polyester will work.

Glassing wing center
 

Thanks Fellas for the info. I'll go with the epoxy as I used it to join the wing halves. It's a brand we get over here called Araldite, slow cure stuff. It's a bit thick to use so I got hold of some epoxy thinner called 91-92 from a local boat yard. I'll let ya's know how it goes. Hey Ed, would metholated spirits be denatured alchohol? Thanks again men. Regards John.

Glassing wing center
 

The jobs done and it turned out ok except for a bit of the weave showing up in places. I filled in these low spots with micro-filler and will cover the wing next. Thanks again. Regards, John.

Glassing wing center
 

John,

They are two different animals. Your best source of supply for the denatured alcohol is a pharmacy or a hardware store.