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Old Jan 31, 2016, 09:24 PM
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Canada, SK, Division No. 7
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Fixing EPP "road rash" on underside of fuselage

Had to put my unlaminated EPP plane (Bormatec Maja) down on a very rough ice surface at ~60kph.

The landing was as good as I could have hoped but the ice worked like a rasp on the bottom of the nose. There are little pieces of EPP strewn for 50 yards, no gluing them back on.

I've injected Gorilla glue into torn areas and pressed those back together, but obviously there is material missing. I'm thinking just to fill with Gorilla, probably in a couple stages, sand it down and paint black to match the plane. Then put a coroplast skid plate over the area!

Any better ideas?
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Old Jan 31, 2016, 10:23 PM
rocketsled666 is offline
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If it flies, I can crash it.
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There's a product designed specifically to be used by us hobbyists to fill foam that's got chunks missing. But I'll be damned if I can remember what it is called. Only that the demo video showed it being applied to the damaged nose of the purple Horizon Bearcat foamy.

But as an alternative, I've used the expanding foam insulation filler you can buy at Home Depot (or similar). Makes a mess going on, but sticks to the old foam like nothing else will, and is relatively sandable once cured out... but it's yellow/brown, so you need to repaint or it looks ugly as hell...
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Old Feb 01, 2016, 09:54 PM
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Light weight Spackle mixed into some water based polyurethane works wonders. Sands super easy. Light weigh Spackle feels like the container is empty when you pick it up, so it adds next to no weight. I use Minwax WATER BASED polyurethane.

Mix the stuff together so you have a thick milk shake consistency. Use what ever is handy to smear it into the gouges, you can even brush it on if the damage is small. Use several coats to build up an area. It dries quickly that way.
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Old Feb 05, 2016, 05:27 PM
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Canada, SK, Division No. 7
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I ended up using a mix of regular polyurethane (gorilla) and water based pva wood glue. Heard it recommended somewhere. 20-30% PVA and remainder polyurethane.

This is a neat mixture producing a large volume of sticky, fine bubbled foam. It sets quickly but is flexible before it finally sets, so it can be shaped or pressed down.

It worked so well I decided to use it to also try to repair a foam rudder that went through a pusher prop. 3 pieces and 20% missing, otherwise garbage, and it now looks as new other than the colour of the fill. Very impressed!
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Old Feb 07, 2016, 07:03 PM
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I had this happen to my seaplane on ice and snow!
Beacon foam finish worked great to fix the rough spots.
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Old Feb 10, 2016, 05:56 PM
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I am working on a few builds that will need some smoothing out with something like lightweight spackle. I am wondering what the consistency of it is when it dries, is it brittle and chips off or is it able to give a little? What about some of the mixes you have made, like the wbpu and spackle, is that able to give a bit? I think I have heard of white gorilla glue and lightweight spackle, how does that act? I want something to cover the inaccuracies on a wing, but also be able to move and give with the foam of the wing, so it doesn't flake off.
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