I am new to the idea of glassing!!! I have an all-balsa P-51 and I would like to glass it!!! It has a 65" wingspan and it weighs 8.5lbs!!! What type of cloth should I use?? What is involved in glassing??? How much weight is involved?? What type of surface preparation do I need to do?? Basically, any advice you can throw at me would be fine!!! Thanks!!!!!

Use 1/2 ounce to 3/4 ounce glass cloth. You can apply it with slow drying epoxy, laminating resin or clear polyurethane paint.

The underlying surface needs to be as perfect as possible. Sand it, sand it some more. Look at it under good light. Yep, it still needs more sanding.

Now sand it again.

Vacuum it and get ready to glass (after sanding it again).

Start from the bottom. Use SHARP scissors to cut the cloth. You can also put the cloth between two sheets of newspaper to help prevent fraying.

You DO NOT need to use spray glue, CA or any of the other stuff that people suggest to hold the cloth in place. It's more work. Lay the cloth over the surface and pour a thin bead of resin down the center.

Use a pieve of 1/8" balsa sanded smooth with rounded corners (to prevent snagging) and scrape the resin out from center. Keep scraping. Add more if necessary, but you want to remove as much of it as possible. The resin is only there to hold the cloth down - not to fill the weave.

After it is cured, give it a very light sanding to remove the rough spots and feather the edges. Then do the sides the same way. Lastly do the top.

I prefer to use laminating resin because it is the perfect consistency and it dries harder than regular epoxy which means it sands better.

I've never used polyurethane, but some guys are using it and like it. Apparently the technique is the same.

If you use regular SLOW DRYING epoxy, DO NOT thin it with anything. Some people do, but there are plenty of stories about the stuff not curing properly and it's not necessary to thin epoxy ever. Just warm it up a little in a pan of warm water to get it thin. The working time will go down though because heat speeds the chemical reaction.

Overall, fiberglassing will give you a great long-lasting and durable finish and it's not hard to do. Once you start you'll realize it's pretty simple. Just make sure you work over newspaper and have all your stuff ready before you start. Make sure your work area isn't cluttered.

Cafeenman,
Good technique, any particular brand of laminating resin
that you prefer and is the polyurethane water based?

Thanks Dave

The last laminating resin I used was something I purchased in Germany. I wasn't even sure it was laminating resin, but it came in three bottles (2/1 mix) and was watery.

I used it on several projects and fell in love with the stuff. I now have some Z-Poxy laminating resin, but it's unopened, so I can't say how good it is.

As far as the polyurethane goes I think it is water based. There is a current thread somewhere that I read last night where the guy was talking about using it for fiberglassing. I don't remember what thread though.

Everything that Caffeenman says, but to add just two little things -

First, you will know when you are really getting the resin out of the cloth because the wiper will "buzz" on the weave in the cloth, even with 1/2oz. You will know if you got it right when the resin is set because your fingers will feel the weave as well.

From that comes the second. As Caffeenman says, give it a light sanding...I use a piece of w&d400 grit and just brush very lightly with it. On those bits where you want to "taper out" the cloth use 200 grit and a 1" square sanding block. Why? So that you know exactly what you are sanding and where. The big danger is that with so little resin over the cloth it does not take much before the sanding starts to cut the glass fibres. At that point you have wasted the glass, resin and time.

By the way, the glass doesn't add strength like people think. It's actually fairly brittle, but nothing to be concerned about. What I'm saying is that if you crash, the glass won't save the plane.

The whole purpose of a fiberglass finish is to get rid of the wood grain in as light and fast of a way possible. The glass gives you an excellent surface for your finish.

CafeenMan,
l was also under the impression that fibreglass added
strength, which was a benefit besides providing a paintable
surface. lf strength is not really improved then why not
use iron on super coverite fabric and avoid the mess?

Fiberglass is light, 100% fuel proof, doesn't peel up around the edges or bubble in the sun. You can paint it so your plane doesn't look like a plastic toy. You can repair it so that it never looked like it was damaged (repair, sand, fill, prime and paint instead of patch, patch, patch).

It has some strength. I didn't mean that it's weak. But the reason for using it is to give the plane an excellent base for paint.

Everything cafeenman says.

Glass tends to add stiffness (try bending one of my ffhlg wings ).

It is a matter of measure as well, glass does not add anything like the "strength" of carbon.

But what must be remembered is that neither will support a substrate beyond that element's failure.

A cf spar will rip through a foam core if stressed too far. Glass will crush foam. A cf spar will destroy a built up balsa wing (I know that one ).

probligo - I'm curious about the hand-launch gliders. How high can you launch one and how long do they stay aloft?

I know it depends a lot on the launching technique, but one reason I never got into gliders is because walking three hundred feet to stretch a high-start, launching your plane and doing it all over again 3 minutes later has to get old pretty quickly.

I've got a good throwing arm, so maybe this is the way to go. What can you tell me about them?

Hey, Caffeenman, I fly (not very well) the modern versions of the old sheet balsa heave and leave models.

Most are in the 16" to 20" range, and it is not worth even thinking about glassing them. AUW is less than 30grams.

I have three in the 30" to 34" range. Two of these are glassed.

LE.s are generally kevlar thread or ribbon.

Radio. Whaddat?

Oh... ok.

Umm... I'm not embarrassed to admit this. I still like to fly paper airplanes, chuck gliders, kites, you name it. If it flies and it's not a fly or a mosquito, it's good to me.

I bought several Graupner glider kits while I was in Germany. They are really nice and I figured it would be a good way to lure some of my nieces and nephews into the shop and get them hooked. They range in span from 18" to 1 meter and were really decent little kits.