ive got the wing on my ultrasport all framed up now i need to apply the glass. ive never dont this before but heres what i think i should do (tell me if its correct)
mix 30 min expoy with alchol (to thin) but at what ratio?
spread some expoy onto wing, lay cloth down
pour expoy onto glass, use a credit card to squege the epoxy all over the glass
let cure

is it really that simple?
i dont have finishing resin so how do i do this w/ epoxy?
the ultrasport instructions say to use thin ca. which would waste a whole bottle + some not to menton the fumes so im not going to do that.

Finishing resin is the way to go if you are using epoxy. I did read an article in RCM years ago about using polyurithane to glass a plane. It sounded easier and cheaper than resin. I should still have a copy of it some where. If I find it I'll pass it along.

Pduck

No not epoxy..
there are 2 types of A.B. glues, the epozy resin we use for building planes... the stuff you have.. and there is GLASSING epoxy.

bonding epoxy is far more flexible and rubbery... if u have an old pot u've used in the past to mix it in.. prod the solid lumps.. there is definately a spongy/rubbery feel to it.
glassing epoxy cures very solid and brittle... thats why the glass is needed to hold it together.. the structure you'll build wont have its strength from the glass.... its the epoxy, held to the glass.....

cyano works fine apparently but i've never done it.. Other than that, yeah its glassing epoxy you need i'm afraid..

p.s. a bottle of cyano seems cheap to me..... just do it in the garage or something?

Well, I'm assuming that your talking about the center section that your glassing, if so, then your close, the problem with thinning the epoxy with alchol is it will become kinda rubbery. With 30 minute epoxy, you can heat it up in a bowl of hot water to make it less viscious. I would recommend doing the top and then the bottom seperate, it will give you the time to do it nicely and avoid screwing it up. Another trick is to put down a thin layer like you said, put down the glass ontop and then squegie the resin through the glass, then take the backing material from monokote( the clear stuff) and place it over the glass and squegie the plastic down smooth, let it dry, pull the plastic off, it won't stick. It will be smooth as glass (pun intended) and the edges will have the excess epoxy creating a small transition fillet from the glass to the bare wood. This minimizes sanding, therefor cutting down on time of trying to blend it to the wood.
But, here's the deal if your planing on using it for glassing the entire wing, DON'T DO IT! it will kick too fast for you to be able to get the entire panel done in time. Your better off buying the finishing resin, or west system,MASor system three resin and slow hardener.

Just use thin CA. I thought the same thing as you that it would use a whole bottle & fumes, but honestly it wont even take a 1/5 of a bottle. It goes a LONG way. I prefer to use medium CA though as it doesn't run everywhere and make such a mess. It works fine and you don't use very much so the fumes are ok. Run a fan while you do it if you're worried about fumes.

Jim, you are talking about the center section aren't you???

ya its the center section not the whole wing. ill try heating the epoxy in water to thin. could i use a heatgun to help? being careful not to burn the wing
i have medium ca (not much) but no thin, i dont want to buy a bottle just for this (thin ca is worthless imo, it sokes into the balsa making it totally useless). i can tollorate ca in small amounts but when i pour more than a few drops my eyes burn really bad.

If it is just the center section use epoxy I use 30 minute and the cc method. If you are talking about glassing the whole thing (wing/airframe) I would use fiberglass resin. I used to do that to my boat hulls it looks like gel-coat after it is sanded and clear coated. Makes a really nice finish.

I've successfully used a heatgun to thin 30 min epoxy when glassing a wing center section. I was assume this is slightly more convenient than the hot water method.

Also, no sure why you think thin CA is worthless. Except for the potential for fumes and the potential of gluing yourself, it's a great tool when used correctly, i.e. wicking it onto tight fitting joints.

Save yourself a lot of trouble and just get the Finishing Epoxy. Its thinner, wets the cloth easier and quicker, and you don't have to worry about trying to heat it to get it to flow well. Your final result will be far stronger than it needs to be anyway, and its not that expensive.

If you don't have the backing from your covering available, waxed paper works very well. The easiest method I've found is to lay out a piece of waxed paper, lay out the glass cloth on the waxed paper, and put the epoxy onto the glass cloth. Don't drench it, just get it wetted out. Dabbing with your fingers while wearing latex or nitrile gloves works very well. Now pick up the waxed paper and lay the cloth in place. Use a credit card (or hotel room key card) and squeeze out excess epoxy. Leave the waxed paper in place until the epoxy has fully cured (24 hours). It will remove very easily from the fully cured epoxy. If you try to remove it before this stage, it will stick and tear and leave a mess that will have to be sanded off before covering.

If you do it right, you'll be able to see the weave of the cloth when you pull off the waxed paper. If you want to add a final coat of finishing epoxy afterward, it will leave a very nice glossy finishl

Finishing epoxy is also very good for fuel proofing, clear coating over painted parts, and even making repairs to clear canopies (as long as you don't get the amber tinted epoxy. Get the clear.) Its well worth the investment. It should be readily available in your LHS.

Brad

if it was just out the backdoor id go get some, but its a hour andd a half drive to the lhs and it just snowed 6in out side so it will be much longer. unless ace wallyworld or homedepot would have it im out of luck.

Just use the 30 minute and a heat gun does work, just keep turning the bottles so you don't melt the plastic. Test the wax paper, sometimes the wax paper does stick, I only recommended the clear backing due to my personal experences, almost nothing sticks to it.

Pic Epoxy has a fast cure laminating resin that works well for small projects. It can be applied with a playing card. Acetone is the preferred thinner, but epoxy should not be thinned too much or you could end up with a goeey mess.
I like CA also, it takes very little to saturate the glass. I do not use thin CA though, I think medium is a better choice. Mist the cloth with contact adhesive spray just enough to hold the cloth in position, then apply the cloth to your project. Once the cloth is in position, start working the CA into the cloth, you can use a scrap card to spread it out.
The fumes are bad news, this is the biggest drawback.

Do as planebuilder said. 30-min epoxy works fine for this (I've built 5 or 6 Ultra Sports)

As for heating epoxy, I mix it and then give it 5 or 10 seconds in the microwave (It don't take much!)

Micro wave, I don't even want to tell my micro wave story, that was an all day job cleaning it, not epoxy or anything model related anyway but what a mess!!! Center section, just 30 minute epoxy and a heat gun makes it run like water. Thin CA?? I buy it in 8 ounce bottles, I seem to have found a use for it.

awww i love microwave stories
i had a lot of fun fiberglassing
heres what i did, i used 2 different approches
for bottom
mix epoxy heat w/ heatgun, pour on wing, smoothen out, throw fiberglass on, mix more epoxy, heat again, pour on fiberglass, squegee around, place covering backing on, squege more,
i used a lot of epoxy (read my sig) but was very smooth
on the top i used less epoxy same method as above except this time i heated the epoxy while it was on the wing and squegeed all around, this allowed the epoxy to soke in much quicker (compared to useing more epoxy like i did on the bottom) but it wasnt near as smooth
either way they both worked
anywho here are the the results (pics arnt totally accurate)

Hi!
Sorry! I don't won't to be rude in any way ... But that looks terrible!

It's not a good thing using so thick and so straight edged glass fiber. The reason for this is the edge is working like a cutting edge where the wing is likely to split. And second, using glue epoxy glue is not recommended,it's too thick and rubbery! Ca should also be avoided as there are much better alternatives.

What you should do if you want to have a strong wing center section with no visible edges is to use several layers of 25g glass weave that you cut in a diamond pattern so the largest is above all the rest. 4 layers is enough for a .40size plane. And you use either polyester resin or better yet; 24 hour professional epoxy . This epoxy is thin and cures after aprx 24 hours. You lay the glassfiber on the wing , pour out the epoxy and either brush it out or use a plastic spreader from SIG or Flash. Do not use a credit card as these are to thick and small.
No hair spray or any other such thing is needed!!!

When you are finished you roll a paper towel over the surface to suck up unwanted epoxy, if the surface is hard to reach, you use a small peace paper that you dab onto the surface.

When it comes to laminating epoxies West systems make a rather good one, but there are better ones available if you seek the web.

Naw, that looks just fine.

This fiberglass is not there to make the wing look pretty, it's there to add strength to the center joint.

The bottom will be covered with the belly pan blocks and the top will be covered by the fuse and fillets, so there's no need to make it look pretty.

Oh you smooth talking devil you.