Birman

One of the guys in our club told me to use water based polyurethane to apply fiber glass. Has anyone used that method? It don't seem like it would have the same strength as epoxy or resin. I wouldn't be glassing a whole plane, just the areas where the elevators are joined with wire and the center section of a wing. It would probably be easier to sand than epoxy or resin.

Birman

Ram Jet

I'd like to try it on a scrap piece of wood but I think you are correct about the strength of it.

Bill

vicman

My Feedback: (10)

First, your strength doesn't come from the resin it comes from the fiber.

I know guys who do it and like it. Not the case from my experience. It takes waaaayy too long to harden, kinda like those guys who swear by latex house paint for their models. They forget to tell you about the three week drying time.
I just started using West Systems epoxy for glass jobs and really like it. Sands much easier than Zpoxy finishing resin or any other thinned out 30 min glue. It is a little pricey but works great.

cold_reboot

My Feedback: (20)

I plan on using waterbased Minwax Polycrylic when the time comes on my FW190. If using Waterbased make sure you use something like Deft Sanding Sealer to seal the wood before you apply it, else the water content will warp your sheeting. The Minwax Polycrylic dries to the touch in about 30 minutes and can be sanded in an hour. It's much lighter than epoxy since part of it's weight is water, which evaporates as it cures. Go to TomPierce.net and read his article on using waterbased Minwax Polycrylic and Deft Sanding Sealer, excellent information there and only slightly more weight than conventional shrink coverings if your using 1/2oz cloth to cover the whole plane. I think Mr. Pierce is using the Minwax Poly almost exclusively now.

Edit: If your only covering those small area's epoxy isn't going to add that much weight. WB Poly is so much easier to use (and cleans up with water). There's also no mixing of anything involved, brush it on right out of the can, same thing with the Sanding Sealer I'd use something thicker than 1/2oz cloth for a wing joint tho. You have to do more coats with WB Poly, because it go's on so thin...but if your glassing a whole plane it's the only way I'd go.

huck1199

I like it on foam planes to reinforce joints. It dries pretty quick, but with 3/4 oz glass it takes a few coats to fill the weave.

MasterAlex

If you haven't read Tom Pierce's opus on his SBD you're missing out. [link=http://www.tompierce.net/SBD/html/paint/glasswing.htm]Here's[/link] a link to the glassing section of his SBD build. He did use Poly to glass his plane. Also, Tom posted some Poly vs. Laquer test results [link=http://www.tompierce.net/rcplanes/glasstest/index.htm]here[/link] if you're interested.

Good Luck!

-MA

NoFlaps

My Feedback: (131)

I used the MW Poly stuff on my FW190 and it worked like a charm & dried fast.
one must however, do as cold_reboot said and used sanding sealer 1st to avoid warps.

bps

My Feedback: (3)

I use Sig Koverall with a product called Mod Podge which is a latex sealer, filler and glue. Works great if covering open areas or balsa surfaces. The Koverall is not as heavy or strong as the glass cloth though. I am building a TF Giant P-47 and I will use this method.

Birman

Thanks for all the input. vicman has put me on to West Systems epoxy and I think I'm going to give it a try.

Birman

dhal22

one, water based poly dries in a few minutes unless you are working in a freezing garage. yes it takes a few coats to fill in the weave but you can accelerate that by mixing in talcum powder for a couple of the middle coats. and it sands so easy and smooth. no odor, easy cleanup, cheap and you can buy it at lowe's anytime.

and two, koverall is heavier than some of the lighter grades of fiberglass.

three, yes you have to let latex paint dry for a while releasing gas but again, cheap, easy and readily available. i have so many projects ongoing the paint job might sit for a while anyway. there's always another project to get back on.

Gray Beard

My Feedback: (-1)

I use Poly U for glassing now too, haven't tried the water based yet. Anyway, I tried it this year for the first time and it was the best glass job I have ever done. I have a plane on the bench now that I will try the water based on. As for the center section on my planes not getting glassed I still use resin or epoxy. Been using it for years so why change now, never had a failure in my wings.

Oosiksmith

My Feedback: (1)

You'll either love it or hate it:

http://www.rcuniverse.com/forum/m_79...tm.htm#7964284

TomCrump

We may be missing the original question. Birman wants to reinforce the wing joint. While I use WBP for glassing, I don't use it for this.

I would suggest 30 minute epoxy for reinforcing this joint.

cold_reboot

My Feedback: (20)

I know I got off subject...but his post started off that a guy told him to use WB Poly to apply Fiberglass. Granted I didn't read all the way through his post. Once I had read further than the first sentance and got to his exact question I'd already typed the first paragraph and left it...mostly because Mr. Pierce's website is an excellent read/instructional source for glassing with WB Polycrylic that anyone interested in now, or in the future, for finding a lightweight alternative to glassing with resins. Hence my addition of... if thats all he's glassing Epoxy isn't going to add appreciable weight. If only glassing joints for integrity I still use epoxy and a reasonbly thick FG cloth (same go's for Firewalls).

smithcreek

My Feedback: (25)

I was starting to wonder if anyone actually read the original post. For those joints CA also works fine.