Applying 1/2oz fiberglass to parts - method?

[Dennis Toth]

Guys,
I've gotten into a build project and have some parts that I want to add some stiffness by applying 1/2oz fiberglass with finishing resin. I know the basic technic is to lay the cloth on the part, pour a small amount of resin down the middle and spread with a playing card. Once the glass has wet out, scrap off as much resin as possible then roll over with toilet paper. Anyone doing something different?

My resin is a bit old and a little thicker then I remember, is there any thinner that can be used to get it a bit easier to work with?

Best,      DennisT

[Avaiojet]

Dennis,

I glassed for years with my R/C models, always using Polyester resin. That's how they did it that's how I learned it.

The toilet paper way. 

I personally wouldn't use the old resin.

Sig sells a resin for glassing, however, Epoxy resin seems to be the popular product or choice for the contemporary method of glassing today.

I have used both Polyester and Epoxy resin for glassing.

The thing is, there's more than one way to pull off what you are looking for as to the results. Possibly CF?

Here's my glassing work if you choose to take a peek.

http://stunthanger.com/smf/index.php/topic,29070.550.html

Starts around Post # 554.

Good luck!

Charles

[Chris Brainard]

I use klaskote clear epoxy paint to attach. Lay cloth down and gently brush epoxy through the cloth, pulling out wrinkles, bubbles, etc. Be stingy on this first coat. The cloth needs to be wetted out, but not dripping wet! A thin coat will be adequate to bond it. Let cure and give a very light sanding, basically to smooth dust bumps, etc. Be careful not to sand too much or you can go through the cloth. After that, apply more epoxy to build the thickness. This is my favorite finishing method and it's fuel proof from the bare wood up. Very easy to control the thickness of the epoxy.

The first coat, used to attach the cloth, is mixed with equal parts of clear, catalyst and thinner. For additional coats I don't thin the paint. I've also tried the method of spraying hairspray on the bare wood to seal it before putting down the cloth but haven't been able to determine if it offers any significant advantage. I suspect the thinner in the epoxy paint will simply dissolve it, negating any benefit it may offer in sealing the wood surface and preventing the epoxy from soaking into the wood.

[Dennis Saydak]

I applied the cloth to my Cuda cowl just yesterday with a one-piece wrap around. I used nitrate dope.

[john e. holliday]

That is what I like about fiber glas cloth.  Also for me Epoxy is the best for a base coat and strength.  I quit using poly-ester resin years ago because it was hard to sand and get a decent finish to stick to.   Do as Chris B. says.

[Steve Helmick]

Z-poxy finishing resin works great. I'd brush a coat on, lay the glass on, rub the glass into the resin and add resin as needed to saturate it. Use TP to soak up excess resin as needed, so you have a "dry" look. Roll the TP across the surface, if it's flat enough. Tear off the saturated TP and dispose of it in the garbage.

The good thing about epoxy is that the shelf life is probably 10x as long as polyester, or more. You can thin epoxy with the provider's recommended thinner, or you can use denatured alcohol. Some other things will also work (dope thinner, lacquer thinner, acetone, etc.), but will tend to make the epoxy brittle, which isn't usually a good thing. I don't recall polyester resin to be totally fuelproof, and I recall having some dope adhesion problems.

FWIW, I think the light glass (I've bought and used .6 oz, imported from Germany, but usual stuff here is 3/4 oz/sq. yard) is a nice base for the finish, maybe of some benefit for minor stress areas, but about useless for the nose of a stunter, for example. To strengthen and stiffen the nose, look at 2 oz fiberglass with epoxy matrix. No point to use fiberglass or CF mat with clear dope, IMO. You need to use a resin that will prevent the glass or carbon fibers from cutting eachother. Dope won't do that. I'd be more likely to use Minwax Polycrylic, if not epoxy. But I'd use 'poxy because it's fuelproof, while Polycrylic is not at all.    Steve

[Randy Powell]

I've used them all as well as CA.

[Motorman]

I'd suggest filling the grain a little before you fiberglass or you'll have a allot of pin holes that won't easily go away. Not really a problem on electric but you don't want oil getting under your glass.


MM

[Target]

One way to keep glass from distorting and creeping is to spray the glass with a light mist of 3M77 spray, let it dray almost completely, then place it on the component.
This method works very well inside areas that are harder to get at, and hold the glass in place before the resing goes on.

R,
Chris