Fiberglassing a warbird
 

I'm going to start building a P47 soon. I want to fiberglass it and paint it when I'm done. Question is should I glass the tail and stab before glueing them to the fuselage? Wasn't sure if that would affect its fit in the saddle or not. This will be my first glass job that's why I ask. I've always used monokote in the past. Any comments appreciated

I'd typically glue the tail on and make a fillets first before glassing

good luck

Good point. I forgot about those but would have run into that once I started. Thanks

I just glassed a plane for the first time. I'll offer this as a lesson learned: fix all imperfections in the wood before glassing with lightweight spackle. It will save weight and make the prime and fill step much easier.

Check out the article at http://www.rcscalebuilder.com/Tutori...ng/default.htm

Jerry

I have found that glassing the tail surfaces and the fuse prior to installation makes adding the fillets much easier. I have always had difficulties sanding the fillets when they are adjacent to bare wood. I have been doing fillets out of light spackle and then covering with a couple layers of 1.5 oz glass and then feather sand.

Glueing everything together and then glassing adds strength. With my glassing method of thinning the epoxy 60% epoxy to 40% denatured alcohol, it is very easy to do. I completely finish the model even adding gear doors and everything, then I glass. Model only gets one thin coat of resin to hold the cloth, the weave is filled with a mixture of Red Spot Putty thinned with acetone. No sanding of epoxy and no sanding through the cloth. To get a filler more closely resembling balsa, use 50% light weight Spackle and 50% Durhams rock hard water putty. If you deviate from this mixture in any way, you will screw up.

My Ziroli Panther before ANY finishing was done, all gear doors are permanently installed, I even started up the turbine and taxied it before glassing:

http://www.rcuniverse.com/forum/atta...mentid=2139597http://www.rcuniverse.com/forum/atta...mentid=2139598http://www.rcuniverse.com/forum/atta...mentid=2139599

Finished product:
http://www.rcuniverse.com/forum/atta...mentid=2139600

This is just my way and in no way am I saying it will work for others or is the best way, it is the lightest glassing method I know however.

Totally agree with Luke. I used his method and it works great. Only I use acetone to thin the epoxy instead because there is no water to get trapped in the epoxy if your workshop is not real warm. I also use auto body primer filler that I thin with lacquer thinner about 20% and then brush it all over the glass. Sand all the excess off and then spray a prime coat and your done except for spot filling. I like the blue 3M glazing putty for that. Lots of ways though,and everyone will tell you there's is the best way but you don't need heavy coats of epoxy and all the sanding that goes along with it.

Hmm Fit wing and tailplane, do the fillets and then cover with cloth and glass. Where do you finish the cloth and glass on the wing? If you finish it at the fillet I would be concerned about creating a weak spot there especially if it was a foam wing that had minimal internal structure. I guess it would be OK if it got flown gently.

I would glass the wing and tailplane before fitting and then do the fillets.

Mind you I have a background in building model airframes that are as light as possible but will withstand high G manouvres.

Not sure where you're going with that JD,
Glassing as preparation for painting isn't adding much of any strength at all to a wing or tail surface, relying on 5/8 oz cloth & epoxy would be a mistake,

If it is a foam wing covered in veneer or 1/16th balsa my experience is that the glasscloth and epoxy add significant strength even at 5/8th oz cloth. My concern s that if you have such a wing and you fit it to the fuz do the fillets and then glass up to the fillet you are creating a possible stress raiser at the point of maximum leverage.

I may be worrying unduly as I was working with stuff that did 9ft dia loops at 100mph or were subjected to 40 g loads on winch launches in the final catapult moment.

I don't know many builders who glass to add strength. Most seem to consider it a finishing process..

I always install the stab and fin first, and then glass them. My thought is that a wood to wood joint is stronger than trying glue to a glassed surface.

Glassing with 2oz or heavier cloth at the center section to reinforce a wing joint is common practice,,, but light cloth as prep for paint is a completely different thing.

http://www.rcuniverse.com/forum/atta...mentid=2139736

Well the above model is one I used in 12th scale RC combat. A Focke Wulf TA 152 with a 48 inch wingspan with a MVVS 21 on a Minipipe. The wings were blue foam covered with glasscloth and epoxy. Prior to glassing the wing halves were floppy. After glassing the wings were rigid enough to withstand anything I could do in the heat of combat. Well that was after I moved up to 1 oz cloth. the 1/2 oz stuff that worked OK on the 36 in wings was not up to the job on the TA 152. Ask me how I found that out.

I think you are doing something different than most of us, and you expect different things from glassing.

A nice article on prepping for paint from a pattern guy. They are death on weight gain and like a nice finish. http://www.rcuniverse.com/forum/rc-p...-graphics.html

I like the idea of slathering on a slightly thinned coat of lightweight spackle on bare balsa. Sand most of it off and then start the finishing process.

Ken

I'm with Tom on the glassing, if you have a flimsy wing after sheeting glass isn't going to help. While 2 oz. glass will strengthen a wing joint 1/2 & 3/4 oz. is only a binder for a smoother surface to paint on. Some guys use tissue for the same thing doped on with nitrate and eliminate a weave to fill. Many use epoxy to put the glass on and it will add strength and make a harder surface but it's heavy. One way or the other the wood needs to be sealed to prevent the wood from splitting which balsa does without the glass or silk span.

Leroy

You are incorrect, Monokote adds strength to a structure.

Resin impregnates balsa, this significantly hardens the balsa, then it is all held together with glass cloth. You can feel the increased rigidity in a structure after glassing or after Monokoting.

Anyway, your statement has a lot of inconsistencies and misinformation that I'm not going to bother addressing.

We could talk about our personal experience and not what "some guys do", this is me in the 10 grade with a Jemco FW190D9 that I fiberglassed and I'm 52 now:

http://www.rcuniverse.com/forum/atta...mentid=2139808

Raptureboy,
I'm just curious what brand of auto body primer filler that you brush on to fill the weave..

Thanks,
paul

I've been working these products for 55 yrs. and you have a lot to learn, you know little.

Sorry Leroy but he is correct. Adding even 3/4 oz cloth to a surface is going to add strength. The debate here should really be how strength as opposed to assuming none at all. If you glass a balsa part and it gains no strength then I would suggest your process was not correct.

I use 3/4th oz cloth for "Hangar Rash Protection"....and a base for painting.

A lot of us do but to claim it does not add any strength would be in error. Granted not much strength but it does add some. I use .75 oz cloth when sheeting wings of my pylon airplanes, I wet out the cloth while on the sheeting and place the glassed balsa sheet onto the foam. When glassing the sheeted wings I overlap 12" at the center. I can definetly tell the difference after the glass goes on.

Different strokes I guess,,, when I built quickies way back when, I think I used 2oz cloth in the center section saddle area only, glassing the entire wing would just be unnecessary weight. Your overlapping method basically has 1.5oz cloth at the center,, of course that would add noticeable strength.

Some are missing the point here where strength is concerned. Strength is in the frame work and construction, sheeting and or covering is the wrapping for the integrity of the structure or main binder of a skeleton frame work. !/2 -3/4 oz. glass cloth may firm up the sheeted wood but doesn't add strength to the frame work. An example is you can't twist a sheeted wing without breaking something whether it's glassed or not but an open frame cloth or film covered wing can be twisted.

Hardening of the wood on a glass wing surface is not the result of the glass cloth, that is a result of the product used to put it on, at that point the glass becomes a binder that helps keep the wood fiber from splitting over time and produce a smooth surface to paint on which is usually the main purpose in the first place.