DERF-54

My Feedback: (48)

I have a 44% ultimate with sheeted foam core wings, I would like to glass them so I can paint the whole plane. What is the best thing to use? I plane on using 1/2 oz cloth and would like to use a automotive base coat clear coat system for the final finish.
Any help would be great
Thanks Fred

branded

My Feedback: (9)

You can use West System epoxy, which you can buy at most better boat stores. The kind I use is #105 Resin, and #109 "Tropical" hardener.....

Place the glass down on the wing panel and smooth it out with your hand. The static electricity will hold it in place. Start with the bottom panel.

The glass is applied using the epoxy, thinned (with denatured alcohol) to the consistancy of milk, and applied with a 2" bristle brush. I've tried foam brushes but they pull the glass out of place.

Begin by carefully wetting out the glass. I usually start at the root and work towards the tip, beginning in the center and spreading the epoxy towards the LE and TE.

After the entire panel is wetted out, use an old credit card to squegee as much of the epoxy from the surface as you can. Be carefull that you don't cause runs to develop over the LE and TE to the topside of the wing.

Sand the LE, and TE and repeat all the above for the top of the wing panel.......

I only use epoxy to put down the first layer of glass. For subsequent coats I use a quality water based polyurethane, and sand lightly between coats. Polyurethane is much lighter than epoxy. I never use poly for the first coat as it sometimes can cause the balsa sheeting to wrinkle and warp due to the water content.

The final two or three coats is a mix of polyurethane and microballoons. Sand between each coat as necessary to achieve a smooth surface.

Giant Scale

Your best bet on a aerobatic plane is to cover with monokote or ultracote. You want the lightest structure possible. I wrestled with this question before when building the big planes because a painted plane is more attractive..etc. But the added weight is not desireable on a big plane. The more weight you can remove from the structure the better the plane will fly. If your fuse is fiberglass use paint sparingly to keep the weight down.

branded

My Feedback: (9)

It's an old wifes tale that MonoKote, or any plastic covering is lighter than glass and paint.

You're on the right track, glass with 1/2 oz and epoxy/polyurethane, and finish up with light coats of Laquer color and you'll be considerably lighter than using a heavy film covering material.

Film is easier, not lighter. If done correctly, glass and paint is lighter than the heavy plastic films such as MoneyKote......

Giant Scale

Branded,
Thats interesting..how come most people competitive or otherwise use a film covering? Most if not all competitive IMAC or TOC flyers use film. I find it hard to believe that paint weighs less than film. Do you have any data to back this up? I'd be very interested in this since I am always looking for ways to build lighter structures.

Newflee

Obviously film is lighter than any multi layer finish. However I personally hate film. It looks fake and feels fake. The new larger scale models should be more like their full size counterparts in my opinion. Design intelligent spar and rib structure and you can afford to let the wing skin weigh a little more and do its job, add strength. If your an arf guy and you want the solid real finish of glass you better take some weight off somewhere else. Just make sure its not structural.
Then gain Arf guys should just learn how to enjoy building. Then you can do what you want.

Giant Scale

I am not arguing whether paint looks better than film. Obviously paint looks more realistic than film. But branded claims it weighs less than film.

Newflee

Well branded is using some kind of funky film or some alien glassing/ paint technique I guess. I hope he shares it with us earthlings. All joking aside though I bet that in the near future, modelers will start using the monocoque structure principle in wings more often. Lets face it, when is the last time that a pilot (not dead) told you that he flies a full scale foam core wing pattern aircraft?It would be easier and they would be doing it if the numbers worked. They dont. Furthermore I don't know why people are fascinated by seeing their models do things that full size aircraft can't do. This is modelling. If you want to really get crazy with flight, buy fs2002.

DERF-54

My Feedback: (48)

Thanks for the reply's. The instructions say cover all wings ele.assembly, and rudder with a light glass, so if I have to glass the plane I might as well paint the plane, that is the reason for my question. I do agree that it will be a little heavier than covering but it will look better and I never had much luck covering over epoxy. The west system seems to be the way to go as a few people have suggested it to me. I am glad to have a place to ask questions and get some good answers in return.

Thanks again rcu I'll post some pic's as soon as I can
Derf

branded

My Feedback: (9)

The method I described above is indeed lighter than MoneyKote if anyone, those of you without closed minds, care to prove to yourselfs......

Using .56oz cloth with only one thinned coat of resin, then subsequent coats of Polyurethane (which in itself is near 50% lighter than the resin), yields a covering which is **lighter** than any film out there....Try it yourself on a 2sq ft surface, and compare to similar surface covered in Film.
It's all in technique.
If you glass the structure using the traditional method(s) and techniques, then yes it will turn out **slightly** heavier than film, and the difference wouldn't even be discernable on a 35 to 40lb airplane.

Try it, you'll like it.

DERF-54

My Feedback: (48)

BRANDED
I am using a basic coat of zpoxy over 1/2oz cloth the way you described. When I pull all the excess epoxy off the surface it looks very dry, and when it cures it sands almost perfect, can I then just go ahead and mix my micro balloon's and urethane and sand for a final time and go to primer? What brand do you recomend? All I have done so far is the horizontal stabb and ele.
I wanted to make sure I didnt have a problem before I do the wings, because they are so much larger. Now that I have sanded the parts I agree that there is not alot of added weight from the glass as opposed to ultracoat. I think after I paint the parts I will weight them and post the difference before and after.

Thank you for the help
Fred

branded

My Feedback: (9)

I usually use the polyurethane straight from the can, and apply up to 3~5 coats, sanding between coats.

When the surface begins to take on a bit of a sheen, then you can mix in some microballoons.

The mix should be such that you cannot feel it drag the brush on the surface. If you have difficulty in spreading it on the surface then thin the mix.

Continue with the microballoons, sanding between coats until you have a very smooth surface.

The brand of Polurethane that I've been using is MINWAX Water based Polycrylic, Semi Gloss. I've also used the satin but find it difficult to see when applying.

One more thing. I do use foam brushes for the application of the Polurethane. You can easily wash them up in water after use.

DERF-54

My Feedback: (48)

I looked everywhere today for water based and couldnt find any, the only thing I found in water base there was some polyacrillic and urethane in laquer base and oil base. Any help finding it would be great
THANKS AGAIN
Fred

DERF-54

My Feedback: (48)

I just reread your reply and saw the polycrilic in it , sorry I didnt read it right the first time

GW-inactive

My Feedback: (4)

Derf, what was the final outcome on the weights of the painted panels vs covering?

DERF-54

My Feedback: (48)

Sorry, I haven't finished the project yet. I have one wing built and some of the glass work done but not finished. I will be back on the plane soon and will post my results as soon as I can.
Derf

turbines

My Feedback: (9)

Adding to the post above: One good method of removing the excess resin during the first phase of glassing. I use a good grade of Toilet Paper. Once the resin and glass have been layed down and still wet, roll out the TP lengthwise to the component patting the TP gently. The TP will wick the excess resin away from the fiberglass cloth evenly. Pull the TP off and discard. Keep rolling the TP on and patting it out in this manner until there is no more resin coming off then you will have the correct and lightest amount of resin on the structure. When done it should look to have a satin sheen to it. The cloth will still show a texture. Now you can start your poly coats with baloons.

Jeff Leavitt

Hi,

Been following this thread with much interest. I have a 1/2a pylon ship I'll be working on soon and was giving serious thought to glassing as opposed to Ultra coat I've used before. I'm considering adding one of those flourescent pigments to the epoxy for color so I won't need to paint. Anyone care to guess what would happen if I also added the color to the water based polyurethane used for the fill coats? And lastly, you guys are talking about 1/2 oz. cloth? Man, that stuff is really light and seems flimsy, is it really strong enough? Appreciate your comments... best Regards, jeff....

Steve Collins

My Feedback: (8)

A common mis-conception is that the reason for glassing a surface is for strength. While it might add a very small amount, its primary purpose is to provide a smooth, stable surface for painting.

JohnMcGowan

My Feedback: (15)

Branded, check your inbox for a message please.
Thanks!!! John

Rickd

DERF-54
How did your glassing project turn out? Did you weigh before and after and if so what was your observation? I am about to cover/glass my TF Cessna and the hobby store told me it would add 3 to 4 pounds of weight! They of course sell UltraMoneyCote.

susquach

My Feedback: (1)

If the thread will allow one more technique sugestion: Wipe on a thin film of poly or reson or whatever you are using in oreder to seal the wood against soaking up excess material. Sand the raised grain and proceed as you normally would. Use a very, very light spritz of spray glue to hold to glass in place while finishing work. Hold spray glue can about three feet above surface. and again a very slight sprize will go a long way.
Additionally, a very complete discussion and comparason of the weights of various covering materials appeared in the December '85 issue of MODEL AVIATION. The author ( Phil Poffenbarger ) really gave the subject a controlled workout.

Ddubya