Hey everyone...

I just cant get this stuff in Ireland/uk

Doing the mountain models dl50 and it calls for the stuff.
Ive not done fiberglass over foam with resin either so I need to find a substitute.

A local hobby supplier thinks cellulose dope might work. Hes not fully sure though.

Any guys from uk/Ireland that know off something local ?

Go the extra mile and just use a vac system and laminating resin. Go cheapo if you must.

Check out this link to see just how readily available bagging can be. http://www.rcgroups.com/forums/showthread.php?t=1761515

It looks like this is a pretty close equivalent: http://www.diy.com/nav/decor/paint/w...?skuId=9260759

What you want is a water-based (as opposed to solvent- or oil-based) varnish. Acrylic polyurethanes are commonly used in the states.

You could also use a laminating resin like West Systems, Resin Research, MGS and so on, but those may or may not be easy to find for you. Standard hobby epoxies won't work very well.

Originally Posted by DLGjunkyard

Go the extra mile and just use a vac system and laminating resin. Go cheapo if you must.

I'd like to but since this will be my first time covering a wing I want to keep it simple so I don't screw up .

Originally Posted by Chris Sutton

You could also use a laminating resin like West Systems, Resin Research, MGS and so on, but those may or may not be easy to find for you. Standard hobby epoxies won't work very well.

Chris... Am I right in thinking that laminating epoxy is the big tinned industrial stuff thats pretty watery already.. 5/1 kinda mix as opposed to 1/1 hobby stuff

Obviously I can get all sorts of varnish here but they never say if there water based or oil based mostly..
I checked known brands around here and even downloaded the pdf's but they hide the ingredients used and only use a simple intro to explain the stuff.. I did find a gloss varnish that says polyurethane on the label but ive heard its not the same stuff..

I bagged my last DL-50 with 2oz. glass and epoxy resin. R-2 to be specific. A friend said he'd never seen a DL-50 launch as high as mine. Fibre-glas was never meant to be used with anything other than Polyester or epoxy. What ever material you use wear glove's and wear a mask or work outside. As I've been working with composites since 1971 I think I know what I'm taking about.

I have heard from a number of freeflight guys that the miniwax did not work as well as one might expect. I'll try to find what they now suggest. The big issue was warping of the solid balsa stabs after it has sit in the sun a while.

On a Salsa with balsa stabs, I bagged the stab flat with 0.75 oz glass, making sure that I did not get the glass too dry or too wet. For a fast application, find some 4 mil plastic, put the glass on it and wet it out, remove the excess and then put the stab between the top and bottom layers. Then stack a lot of books on top of it, the more the better. A simple alternative. You could do the mylar thing, even with light 0.007" mylars as opposed to 0.014" thick mylars. I found that for balsa, unlike foam, the plastic will work just fine. It will probably be better and faster than multiple applications of the minwax with sanding in between to seal and smooth. You do not want to add a lot of the minwax because it will soak into the wood and just make the stab heavier.

Originally Posted by prodjx

I bagged my last DL-50 with 2oz. glass and epoxy resin. Fibre-glas was never meant to be used with anything other than Polyester or epoxy.

Id love to be able to bag it really.. But I think It would be too much of a challenge for me for a first attempt.
And on your note about only using fiberglass with epoxy, I was thinking the same.
Sure I've worked with epoxy many times but none that required smooth taught finishes like on a DLG wing.
It looks like that while polycrylic is easier to apply its not as tough as the finish you can get with epoxy resin.
I think I will make a call to the hobbyshop and get a bottle of laminating resin.
Im sure they have the advice for applying it properly.

Originally Posted by Thermaln2

I have heard from a number of freeflight guys that the miniwax did not work as well as one might expect. I'll try to find what they now suggest. The big issue was warping of the solid balsa stabs after it has sit in the sun a while.
You do not want to add a lot of the minwax because it will soak into the wood and just make the stab heavier.

Yes but the dl50 wing is Bluecor foam I think.. Like you said though, I was already told not to use minwax on balsa, But resin instead

In the DL-50 instruction manual it even says that if you are experienced covering a wing with epoxy to use that otherwise cover them using Minwax. I used Minwax and the wing came out pretty stiff (for foam) and only 3.2 ounces but I would have used finishing epoxy had I known how easy glassing a wing is since it was my first build.

If the Minwax holds up to the Florida sun and heat I will be a happy camper after what I read but may regret not using thin finishing epoxy spread on lightly over the fiberglass with a credit card. But the Minwax system was super easy, cheap, fast and no nasty epoxy fumes to breathe.

Originally Posted by overmyhead

In the DL-50 instruction manual it even says that if you are experienced covering a wing with epoxy to use that otherwise cover them using Minwax. I used Minwax and the wing came out pretty stiff (for foam) and only 3.2 ounces but I would have used finishing epoxy had I known how easy glassing a wing is since it was my first build.

If the Minwax holds up to the Florida sun and heat I will be a happy camper after what I read but may regret not using thin finishing epoxy spread on lightly over the fiberglass with a credit card. But the Minwax system was super easy, cheap, fast and no nasty epoxy fumes to breathe.

Yeah I hear ya... I initially wanted to go the minwax route for simplicity but I just cant find the stuff around my parts. I also wouldnt like to blow the whole build trying a different type sealer because I couldn't be sure any would be similar to that polycrylic stuff.
Looks like ill have to use finishing resin and pick up a few tips along the way .

Just make darn sure you don't use polyester resin, I think it melt's blue foam as well as white.

There are just to many pluses to ignore when using laminating resins. The wing surface finish will mirror the shine on the mylars, The overall weight should be lower, Laminating resin can be used for many many other duties and likely even has a longer shelve life than minwax. It will not soften as easily in the heat and can also provide a long work time envelope when using slow hardener.
As mentioned, E glass was made to be used with epoxy.

I dont know what the spar system is on the DL50 but its likely if you mess up real bad you can still recover the spar by melting the foam away with acetone. Mtn models sells wing cores if I recall so its a pretty good opportunity to learn a new aspect of building.

http://www.mountainmodels.com/produc...roducts_id=353

Originally Posted by DLGjunkyard

I dont know what the spar system is on the DL50 but its likely if you mess up real bad you can still recover the spar by melting the foam away with acetone. Mtn models sells wing cores if I recall so its a pretty good opportunity to learn a new aspect of building.

http://www.mountainmodels.com/produc...roducts_id=353

Funny you should mention that.. I put in an extra set of wing cores and tails for my order.. I had a inkling id run into trouble before I even started.

I also added some .002oz. carbon vail/tissue to my T/e's to make them sharp and strong. I sandwiched them betwee the glass skin's.

Originally Posted by prodjx

I also added some .002oz. carbon vail/tissue to my T/e's to make them sharp and strong. I sandwiched them betwee the glass skin's.

The Validol, as well as others perhaps, lines the TE of the stab and rudder with 1/8" (or so) wide CF uni tow. The Tow provides better resistance to damage. CF matt basically absorbs a lot of resin and might not give you the desired strength.

But how might you add it easily?

Take Tow and lay it out on some plastic sheet, taping the ends down so they do not move and the tow is as flat as possible. (you might roll it a bit). then spray 3M77 on the one side of the tow. Use a bit of 3m&& since you want the adhesive there. Then let it cure/dry. Taking the tow and a small monokote iron, position the tow with the adhesive side on the foam and iron on the tow. Trim as necessary. Then do your layup. I have don't this with pre-cured CF pieces and the 3M77 melts and adheres to the foam exceptionally well. Well enough to rip out the foam if you decide to try to remove the CF.

Simple and easy.

Chris