What epoxy are people using now days to make glass fuselages. I just did an Aquila in the factory mold I acquired. I used the epoxy I use on my full scale Long EZ. It's really dark in color and takes a bit more to wet out the fibers than the old epoxy we used 30 years ago making contest gliders. Any good recommendations on the epoxy to use now days would be appreciated.

You might post in the Composite Fabrication, and Repair thread. Personally I've had great results with West Systems Epoxy. For most of my projects I use the 105 Epoxy, and 206 Slow Hardener.

Thanks Greg, that's what I was wondering. I have that here too. I will try it. I used way too light of cloth. It came out of the mold really bad.

I suggest you check out US Composites 635 resin. I’ve been making 2 meter pattern airplanes with it and it’s great stuff. I’m able to manufacture a 75” fuselage that comes out of the mold pre primed and with formers that tips the scales at 31oz. I’ve tried West Systems and found that it didn’t produce as stiff a part. To get the same strength more cloth was required.

I fiberglassed my last plane with West and the surface was pretty soft. I would love to know the difference in hardness between West and US composites 635. I'm even considering going way back to polyester finishing resin to get a harder surface.

carl

I use FGCI 4:1 Laminating Epoxy resin. It works very well for fiberglass applications, liquid enough to fill heavy weave, easy to sand. If mixing for light fiberglass 1.4oz or less, I do slightly reduce. I mix it 4:1:1. 4 parts resin, 1 part hardener, 1 part reducer. It also mixes very well with Microballoons and easy to sand.

I couldn’t find 4:1 on their website. So you would have to call them. I normally go to the store. They are very knowledgeable, and primarily a fiberglass store for boats, and other fiberglass vehicles.

https://fgci.com/shop/



The curing agent is 4:1.

Since Hysol 9462 has been difficult to buy. I use their structural adhesive.

https://fgci.com/product/structural-...sive-mp-55300/

I would not recommend West systems! It does not get as hard as the epoxy I have been using the last 10 years from EMC-Vega in Germany.

Carl, the USC 635 is much harder after a few days cure time. It responds very well to an elevated temp post cure. I frequently let parts post cure in my car on a warm day. I would absolutely never make a structural part with West epoxy.