Glassing Techniques?
 

Hi,

I know everyone has their preferred method. I've been using Z-Poxy 2-part resin for years with good results. Recently, someone told me that they had more luck with polyester-based systems, and that the squeegee method worked better than the paintbrush method (used with thinned epoxies). What methods/products are those of you that still build using? Why?

RE: Glassing Techniques?
 

I use Z-Poxy straight up, not thinned. Squeeqee it with an old credit card or playing card until no shiny spots are visable. Add a fill coat of resin (again, straight up), and squeegee everything that does not fill the weave.

Personally, I brush prime with a 2 pack primer, and sand all that does not fill remaining weave that I missed with the resin.
Spray prime, wet sand, and call it a day.

Jeff

RE: Glassing Techniques?
 

Hi Shaun,

I've become a firm believer in Aerospace Composites EZ Lam epoxy. 2:1 mix ratio thinned with alcohol. The directions for the product say to thin 50% but I don't use near that much. Very low viscosity to start with in my opinion. The stuff goes on great with a brush still using the playing cards to squeegie the excess out. You can get 30 min or 60 min tack time hardener - I've been using the 30 min. Plenty of time to work with and the stuff goes a long way. I used to use Z-Poxy with good results but with this epoxy the next day it has NO tackiness to it whatsoever. Dry as a bone. Has made me a much better glasser than I used to be. The Hornet wings look unbelievably smooth compared to the stabs that I did with Z-Poxy.

Dan

BTW, The Phantom kit looks great. Can't say enough what you did for me.

RE: Glassing Techniques?
 

The lightest method and the easiest, to great qualities! That would be Z-Poxy thinned about 40 percent with denatured alcohol. With this method there is absolutely no excess resin, you don’t have to scrape anything off, so you don’t get resin all over yourself and your shop.

To fill the weave of the cloth the biggest mistake you can do is fill it with another coat of epoxy, not only is this extremely heavy, it is also a lot of work to sand it off. I mix acetone with auto body spot putty to a consistency just a little thicker than milk. Brush this on to fill the weave, it is very light weight, it sands off extremely easy and you can sand it down to the level of the cloth (most is sanded off) and it fills the weave perfectly.

Next add your favorite primer and sand most of that off and you’re done. The point is, the putty and primer sand very easily so it is easy to go down to the cloth without harming it. Trying to sand resin off is labor intensive and you are always in danger of sanding too much off.

RE: Glassing Techniques?
 

I am a previous user of Z-poxy. But now all I uses is West systems with the same principles, IMO this is the best stuff on the market.

RE: Glassing Techniques?
 

West Systems[sm=thumbs_up.gif][sm=thumbs_up.gif][sm=thumbs_up.gif]

Kevin

RE: Glassing Techniques?
 

I used to thin with alcohol, but found it soaks into the balsa and adds weight. The aim of the first coat is to glue the glass to the surface. The second coat of resin/primer fills the weave. 90 percent of the second coat get sanded away reguardless.

RE: Glassing Techniques?
 

Kevin,

What's ur application technique with the West Systems? I've been hearing about it for years, but I don't know anything about it.

RE: Glassing Techniques?
 

Go to my web site and read my system.......Almost no SANDING...Lightest way to do it...IMO

RE: Glassing Techniques?
 

Terry, I'd like to read up on it, what web site is that please?

RE: Glassing Techniques?
 

West Systems is the bomb!!

RE: Glassing Techniques?
 

http://terry_holston.tripod.com/id4.html

RE: Glassing Techniques?
 

Thanks Ben....................

RE: Glassing Techniques?
 

What weight polyester do you use or is it "about right/silk feeling, tight weave light"?

Also, have you had much of any problems lifting off cured glass other than just once in a while?

I like the method - mimics vacuum bagging with a release film - very clever!

RE: Glassing Techniques?
 

What have you used it on?

RE: Glassing Techniques?
 

The polyester cloth I use is about like your significant other's silk scarf.........Color doesn't matter, Ha Ha

It will not peel up as long as you leave enough excess to get a good grip on when peeling it up.

Yes almost the same as vacumm bagging, I did this because if you ever tried to vacumm bag a built up structure, It gets squashed between the ribs, NOT GOOD!

RE: Glassing Techniques?
 

Terry,

VERY interesting. Can you be any more specific about the polyester cloth? With my luck, I'd surely buy the one type that sticks to epoxy wonderfully.....

How much pulling pressure are you typically using? How hard do you have to pull? Have you done this on large surfaces (like the size of the wing on a Yellow F-18 Twin?

RE: Glassing Techniques?
 

Iv'e used the old K&B Superpoxy Polyester resin for years. I did these models, the Cessna is all Balsa TF Kit. and the F-18 is an old DCU f-18 kit, Balsa wings and stab with polyester. They were built in the early 90's. Pix taken today.
I always used 1 layer of 2 oz cloth. so it was less likely to dent. Also with poly, you can do 2 or 3 coats in a single day. Because it drys in 45 minutes sandable. I have an Oven
large enough to get an entire plane in.

RE: Glassing Techniques?
 

Just be sure it is polyester, trust me epoxy will not stick. If you get too much epoxy on it my be hard to pull free, as the thickness of the epoxy on top will make it stiff. I am frugal with the epoxy.................. The hardest part is getting it started to peel. Once it starts, it comes loose easier.

If you have any doubts, do a sample layup on a piece of junk lumber. Once you try it you wont go back to the toilet paper method.

Oh, wear rubber gloves when using epoxy of any brand. I work with epoxy every day and I go through 10 to 20 pair a day.

I used this method on my Ziroli Panther wings and tail surfaces. I added carbon fiber Vail under the 3/4 oz glass cloth, made the wings bullit proof!

RE: Glassing Techniques?
 

Terry: Off topic... What Scale is the Corvette? It Rocks...

RE: Glassing Techniques?
 

1/4 scale, for Connely V-8.

RE: Glassing Techniques?
 

Its feeekin!!!!!!!!!!!!!!!!!!!

RE: Glassing Techniques?
 

So,

Which West Systems setup (hardener) is best for glassing wings? Where's the best-priced source for it? Have any of you used it with thinners like acetone? Thanks.

RE: Glassing Techniques?
 

aircraft spruce and supply has good "kit" prices for west systems

i think i am still partial to the EZ-Lam

RE: Glassing Techniques?
 

Don't use Acetone with West's. I use the base 105 and the 206 hardener. Works great. About an hour working time. Tacky out to about 2 to 2.5 hours. Trim it while green at the 7-8 hour mark, at which point you can work with it as well, such as sanding, etc. Reaches max hardness in 4-5 days.

Lance

RE: Glassing Techniques?
 

Terry,

Could you use peel ply rather than the polyester cloth?

Roger

RE: Glassing Techniques?
 

Hi,

Just ordered my West Systems kit from Aircraft Spruce & Specialty. Thanks, guys! Now I've got to test this method out on something before I use it on my customer's jet!

RE: Glassing Techniques?
 

I don't think this technique has been covered here so I'll give my 2cents. The applicator I now ues is a small roller for most large surfaces. Doesn't matter which epoxy (although I like EZ Lam) you use. The technique is the same as painting a wall. Very small rollers can be bought off the net or you can use the small foam ones from Home depot , Lowe's etc. The advantages are two fold.. first the epoxy is put on evenly on the surface and little is used. Second it levels so smooth that you barley sand at all. Just another method do try.

RE: Glassing Techniques?
 

Covered my last JHH F-4 surfaces with West System epoxy which I bought from local West marine outlet. You also need to buy the pump to ratio & dispense the resin & hardener (not equal volume). I diluted with about 30-40% denatured alcohol, which makes it really easy to spread & not have any excess resin & very little added weight. West system epoxy has a longer set time than the 30-min variety, so one does not have to hurry with the job. Best to use the paper cups from West with the wider mouth, as this leaves a shallower the mix that dissipates heat; which otherwise can accelerate its setting. Have fun

Phil

RE: Glassing Techniques?
 

Sure, thats what it is for..........;)[8D]:D

RE: Glassing Techniques?
 

I use West Systems applied with a small foam paint roller.

RE: Glassing Techniques?
 

I roll TP over the surface after each application of resin. The TP soaks up the excess very well and helps to minimize sanding. Just remember to keep removing the top layer so you always have a fresh sheet on the top of the roll.

Mark

RE: Glassing Techniques?
 

Mark give up the Toilet paper and save it for "important" work lol. The paint rollers work much better.

RE: Glassing Techniques?
 

Paint roller on - cheap TP off.

BTW, I don't use the cheap stuff for the "important" work.

[sm=lol.gif]

RE: Glassing Techniques?
 

This methods works well.

Final sand surface with 400 dry.
Remove all dust and the go over surface with a tack rag.
Spray a light coat of flat lacquer (rattle cans work great) over entire surface.
When dry ( almost immediately), lightly dry sand again with 400 paper dry.
Again remove dust and tack surface.
Apply glass cloth and resin of your choice just enough to penetrate the glass and leave a dull surface.
Let this dry completely. The lacquered surface will prevent over penetration of the epoxy into the surface.

Next apply Transtar Epoxy surfacer either by brush, roller or spray. 1 to 2 wet coats. let dry overnight.
Rough sand with 320 dry and the 600 wet. Nice filled and primer surface with minimum weight gain.

RE: Glassing Techniques?
 

I use the Z-poxy thinned about 60:40 with alcohol, apllied with abruch starting at the center moving out to the edges. After I let it sit for a few minutes, I blot the surface with a paper towel careful not to lift the cloth, if you rub lightly with the paper towel from the center outwards it will make sure you have removed any "bubbles" and will also dry the cloth to a point where you can almost touch it and it feels dry. I always thought the idea was to bind the cloth to the underlying wood, which gives it strength and also prevent the cloth from coming up. I have used this method successfully and it very easy. The Z-poxy is ready to sand in 18-24 hours and there is no need for a second coat, only filler (red putty thined with acetone) brushed on and sanded and you are ready for primer.
I have not tried the West systems but hear it is just as good. For me the paper towel works wonders for keeping it light and easy to sand.
Tommy

RE: Glassing Techniques?
 

I agree with DocYates. The resulting monoque glass envelope is relatively much stronger than the balsa substrate, but needs to bind to the balsa to maintain its shape for strength. Incidentally, the West system is a laminating epoxy & significantly lower viscosity to begin with, so with the 60:40 alcohol dilution, is relatively easy to avoid excess epoxy.

Further to my post earlier, the West system will still heat up while in the paper cup (sandae size?), so needs to be poured to the middle of the glass surface & avoid exothermal heat build-up. Then it does not begin to set until the alcohol has flashed off. After allowing a day or 2 to fully set, I sand it down lightly with new 220-grit paper on long block, just enough to remove the surface bumps without cutting into the glass. One can feel a much smoother surface after a few passes with the sanding block. For filling the web, I follow this with a layer of epoxy mixed 50:50 by volume with micro-balloon & appropriately thinned with alcohol, since strength here is no longer the objective. Another light sanding & its ready for primer. Don't forget the blue gloves & dust mask when sanding. These are nasty stuff to come in contact with.[:o]

Phil