Glassing Question
 

Hi Guys,

I have been scratch building my jets for along time. When I have glasses wings, stabs etc. I have only used one coat of resin over the cloth veil. My question is, how many coats of resin do you guys use, and if you use 2 coats, what is the procedure for the second coat?

Thanks in advance,

Ron

RE: Glassing Question
 

You didn't say how you applied the resin. I use a small foam roller and it puts down an even coat. I add a second coat the same way after the first coat is lightely sanded. I think filling the weave with primer adds weight.

RE: Glassing Question
 

Ron,

I always use the method that I read from Dan Parsons. On the first coat, I use epoxy thinned 50/50 (with Acetone or MEK, apparently thinning with alcohol weakens it). That I brush right on over the cloth and don't blot it up. Its very thin and wicks into the wood strengthening it and bonding the cloth to the wood. Then, when that is cured overnight, I brush on a 2nd coat of epoxy thinned 70/30. According to what Dan wrote, you need to fill the weave of the cloth and you can do it with epoxy, or with paint (primer). Both inevitably add weight, but filling the weave with epoxy also adds strength. After the 2nd coat is cured, I do a quick sanding to get any surface roughness and runs that I can see/feel, and then I start adding the primer coats and wet sanding them off to get the final surface before painting...

Bob

RE: Glassing Question
 

Thanks<
I have been using West system epoxy for years and have been pleased. I lay the cloth over the wing and then use a plastic Hotel key to squeegee the resin to a really smooth layer, just filling the weave. In the past I would end there and let my painter do the rest. I have never "thinned" the resin". Not quite sure what to use with the West resin. I really do get a smooooth finish with the cloth, but am thinking the second coat would be better than Primer. Thanks again

RE: Glassing Question
 

:D i use only zap finishing resin.first coat thinned with denatured alc{10%}.spread with a playing card.take all you can off. like putting on a decal. let it dry. longer is better. on the second coat a mix,, 30% Q-CELLS. ,,NOT MICRO BALLONS..,, mix just enought of the cells to turn the resin white. it should flow like ketchup.spead it with the playing card again.this will flow out smooth.sands like balsa. you can go to 400 grit if you want.not much primer neede. just to help the paint to stick.ballons leave holes the need filling,cells dont.also much less weight with ,, q-cells.- if you want to save a little more weight,use .. WARP CLOTH.. has moe fibers in one direction.perfect for wings..

RE: Glassing Question
 

If you are going to use two coats make sure you have the right resins. Some finishing resins have a wax additive to help them cure to a hard finish. If you overcoat them you get the dreaded fisheyes.

I use West system 105 with the addition 410 lightweight filler for the second coat.

Wash down the first coat with warm water then repeat. If there is the slightest sign of the water beading up you have contamination. Wipe down with acetone and repeat the water test.

RE: Glassing Question
 

Back in the good old days I brushed on a couple of coats of K&B clear with the satin catalyst. When I finally ran out of my stock of K&B I had to find another method.

So like BOBH, I use the small foam roller to apply 2 coats of West Systems 105 epoxy. Then sand and prime. I'll be glassing my YA F-15 with this method in the next few weeks.

RE: Glassing Question
 

Thanks Guys!

RE: Glassing Question
 

K&B Satin was the best.

The second coat filles the weave, so you can extend the resin with micro to get a lighter fill. The tough part is the sanding.

The best part of K&B epoxy satin clear was how it sanded. Just turned to powder, did not fill the paper, nothing I have used since comes close.

RE: Glassing Question
 

Has anyone tried Klass Kote clear in place of the K&B? I agree that the old K&B was by far the best, and like Matt said, you could dry sand it. I hate wet sanding.

RE: Glassing Question
 

Be aware that you can finish up in hospital dry sanding epoxy.

Some people get away with it but others, me included, react very badly to epoxy dust and the reaction seems to worsen with repeated exposure. Wet sand only is my advice.

There is an alternative to epoxy in the UK called G4, not as strong and you need multiple coats but they go on very rapidly.

RE: Glassing Question
 

So you are sanding between the first and second coat of Resin? Thanks in advance,
Ron

RE: Glassing Question
 

I usually do a very light wet sand with 280 then roll on the second coat then comes the serious sanding 400 then 600 then the paint. If I am going for a clear finish then I go all the way to 1200.

I have been told that I use too fine a grade before I paint but that is how I do I do it.

RE: Glassing Question
 

I use the "2 thinned coats" as well and although it take more like 3 days for the first coat to dry, i do sand inbetween coats. This is good to help key the first coats surface, and i generally pay more attention to any glossy spots in the first coat, and also any fibreglass overlaps to make sure the surface is ready for the next coat.

Thanks
dave

RE: Glassing Question
 

What do you do if you sand thru the cloth by mistake?