Glass wings

Anyone ever put fiber glass over foam? Any good? is it worth doing and how easy is it to do?
Seen a video of a guy in the states who put fiberglass over a wing and then solarfilmed it! the finish was like polished glass - awesome!

Mate, be careful what resin you use, I used normal fibre glass resin once, I ended up melting the bloody fuzz before first flight.
Tim recommended Poly C it's water based and by the time it drys, it will not add much weight unlike the two part resin. Also foam safe......

Cheers Zaid, actually now remember you telling me about your infamous dissapearing jet story!
So what type of finishings can go over the top of glass then? and what is best? The guy in this video actually used ultracote not solar film,,but as I say the finish was really shiny - like polished glass! very impressive!

You can get a glass finish without fiber Glassing, look at Jermy's Le Fish, it's foam he used poly filler ( the light weight stuff) gave it a good rub (he does that a lot) then covered it with solar film and it looks really nice. I guess the down side to that is if you hit the ground too hard the poly filler will turn into dust/chunks/cracks etc...

My thoughts only
You must have mistaken me for someone who knows how to build or cover ! I am only just picking up these skills, sometimes the hard way (expensive more like).
Best wait for someone who knows what they are talking about!

Cheers for the honesty Zaid!

Seen Jems Le fish and its a nice model! Think that technique of filling and sanding is called spackling - Have spoken about it with a few members in the past and that is one of the major problems with it - if you hit the deck or have a couple of rough landings it cracks and crumbles, ruining the finish!

Having said that, I dont know if hitting the deck with a fiber glassed model would do it any favours either!

If you are talking about EPP foam, then seriously, what is the point? You are putting a nice thin crispy and fairly rigid shell on a nice and squishy foam surface. Sort of defeats teh object really, a bit like lacing EPP with carbon leading edges and shedloads of spars. The whole point of building in EPP to have lots of bouncy squashy goodness, so when you hit the deck, another plane, or Tim, it bounces off, and does no damage. The moment you start adding glass skins, loads of carbon etc, you remove all that benefit.

The best thing for EPP, honestly, is laminating film. It too is nice and tough and bouncy, so works great with it. It gives a nice finish, adds stiffness (especially torsional stiffness which is a good thing!) and most importantly, can flex with the EPP surface on impact. Second best, is good old tape. It works the same way as lam film, and goes round compound curves easier, but is not as slick looking.

If it is polystyrene (EPS) on the other hand, then that is good. EPS is nice and stiff anyway, so adding glass is a good thing. Lots of strength and stiffness added, and a good base for getting a slick finish. EPS has naff all impact strength, so putting a thin stiff shell around it doesn't make things any worse. If anything it makes it better in terms of small ding resistance.

And don't even get me started about putting filler on EPP before covering.......

Andy

Ben...I'm using EPS for the big B52 glider Im doing at the moment. Now I'm not aiming for a super smooth mirror finish but the technique is as follows.
Rub down and fill in with nutty putty or just spackle any large dents or holes ( pea size or greater ).
Ensure the foam surface is free of any noticeable holes or bobbles etc. Then its skinned with thin balsa veneer ( 1 - 2mm is fine ) applied with either latex type contact glue - copydex etc - and then given a nice fine sanding all over. Finally, apply some sanding sealer ( or dope etc ) and then apply the final covering of your choice..... solarfilm type heatfilm, or solartex if you want to paint it.
Alternatively ( and the route Im going ) cover the lot with lightweight glasscloth and resin- but Im using the friendlier water based Poly-C acrylic resin, which dries quickly and being water based cleans up real easy.

Do you still need to spackle the dents etc if you are covering with glass Tim? or glass straight over the top of the foam?
How many layers of glass cloth do you use bud? is one enough?

Stubbsy, have a gander Here, all you ever wanted to know!

Good link Marty. Ben, alot depends on what you intend doing with the model - but as with ANY job, we all know that preparation is the key to a good finish.
One layer of glasscloth is certainly enough in most cases, but you will usually need more than one coat of epoxy or whatever your using. Poly-C for instance needs around 4 - 6 coats, as the first couple just fill the weave, and the rest produce the actual finish.The great thing with PolyC is not only how clean and easy to use it is, but also, its water based, so after its dried....most of the water has evaporated- along with the weight.
Not so with the laminating epoxy ( although that is tougher )

I've epoxied lots of glider wings, the majority I would estimate 80% of the resin is removed only a light skim is needed as the final coat for paint.

The best job I did was on the Alpina wings, still strong & a good finish after what must be 6-8 years, paint has yellowed a bit now though, it's been in the stream a few times as well

So what would be the best top covering for a glassed wing? If I want to make it nice and smooth and shiny?

Wet and Dry it and then a good spray. Then flat it back and polish it.

Paint as Marty said, nice thin coats to build it up without adding to much weight, flatting it in between coats with 1200 grade Wet & Dry with a touch of fairy liquid to remove any silicones. This is where the paint reacts & causes what's called fisheyes.

Make sure the glass is woven cloth not chopped strand, if you have the time HK have it, choose the lightweight stuff

Cheers chaps - sorry for all the questions, but if I was to use Tims Poly C which is water based, would I still need to fairy liquid the wet and dry? and would I need to use water based or non water based top coat paint?

Using the wet and dry both wet and lubed is always best.
It doesnt matter what paint you put on it - its fuel proof anyway so should accept any paint. Water based ( emulsions and acryclics etc are lightest due to evaporation and also generally easier and nicer to work with.)

Never used the water based stuff, I would do a test piece if you decide to use a toluene based paint, any holes or imperfections in the coating will disolve the foam instantly unless it's EPP

Ain't you heard of google?
There have been a couple of posts made while I was typing but the content of this still stands;
We use a drop of washing up liquid in warm water to lubricte the wet
and dry paper which gives a more even cut and reduces scratches.
I can't give you a difinative answer about the "resin" Tim uses but once its cured I see no reason why you shouldn't be able to wet and dry it. My advice would be to do a test piece and experiment.
Shine is a product of reflected light! Any surface which is smooth will reflect light, the smoother the surface the more it will shine and if the material is un-smooth by the very nature of it we have to "fill" the surface irregularities, and then dress the surface (usually with wet & dry) and repeat the process until the surface is perfectly smooth using finer and finer grades of abrasive.
You (or anyone else for that matter) will never achieve a shine if the preperation work isn't done.
Once the prep' work is done the surface needs to be "De-greased" using a surface cleaner which will neutralise grease. (I use a factor bought de-greaser) Methalated spirit will work, even better would be to use white spirit and when it has evaporated a wipe with Meth's. (once you have de-greased don't touch it with your sticky, greasy little fingers!).
Choice of paint depends on a lot of factors! weight, water/weather resistance, durabiliy, toxicity of the application and so on. The three main groups are Urethane/polyurethane, water based and enamel.
The first two require a sealer (Clearcoat). with enamel it is a complete system in its self (but its heavy).
Which ever paint you go for you will need the apropriate primer and then undercoat. As already stated, the finish of the undercoat will ulimatly affect the overall finish.
The drawbacks:
Urethane/polyurethane requires the use of a air flow mask and a well ventilated area away from other people, animals and food stuffs, so it's not feasable to do it in your kitchen for example!
Waterbased paint (acrylic) can not be rubbed down so the application needs to be even and smooth.
Enamel is heavy (but can be flatted back ond polished)
Remember Ben, if you use any spay you need a mask!
This is a huge subject and to complex to fully cover here but I hope the above helps.

Using a drop of wsahing up liquid in some water not only removes greases oils and stuff of the surface you are sanding, but also helps stop the sandpaper clogging up.....

Andy