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Aug 19, 2019, 03:05 PM
Registered User
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Discussion

Fiberglass "skin" over EPO foam?


Anybody have any experience or recommendations for specific types of Fiberglass resin? I know some of it can eat foam.

While not a scratchbuild, I'm planning on skinning certain sections of a new EPO airframe for some additional structure. Would prefer not to melt right through it.
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Aug 19, 2019, 04:00 PM
Build straight - Fly twisty
Whiskers's Avatar
Quote:
Originally Posted by Brett_N
Anybody have any experience or recommendations for specific types of Fiberglass resin? I know some of it can eat foam.

While not a scratchbuild, I'm planning on skinning certain sections of a new EPO airframe for some additional structure. Would prefer not to melt right through it.
Use epoxy resin and all will be well.
Remember to have a high glass to resin ratio. Use just enough resin to fill the glass. Slathering on more than that adds a lot of weight and minimal extra strength.
Aug 19, 2019, 04:02 PM
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Thanks Whiskers

I'll give it a try.
Aug 19, 2019, 04:25 PM
Space Coast USA
hoppy's Avatar
Try the newsprint/glue method for adding significant stiffness to foam. Lighter, cheaper and IMO, stronger. https://www.rcgroups.com/forums/show...ng-improvement
Aug 19, 2019, 04:41 PM
Registered User
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I was thinking of that one too. I have plenty of clean news-print type paper.

Once the model is in my hands I'll have a better idea what needs to be re-infroced. May not need much of anything
Aug 21, 2019, 08:30 AM
Retired CAD guy
birdofplay's Avatar
I'd be trying some test parts !

EPO is fairly flexy and slippery and might still have mold release agents embedded in it's skin.

After some number of flights It might might end up wanting to Shed it's skin
like a bug or snake.
Aug 25, 2019, 10:11 AM
flyin' fool
goldguy's Avatar
I've seen brittle news print covered foam snap like a twig as there's absolutely no flex.

Laminating film is a better choice. That's what slope combat machines are covered with. Cheap, easy to do, strong and flexible too.
Aug 25, 2019, 03:43 PM
Space Coast USA
hoppy's Avatar
Quote:
I've seen brittle news print covered foam snap like a twig as there's absolutely no flex.
What happened to the truck that ran over it?
Aug 25, 2019, 04:52 PM
flyin' fool
goldguy's Avatar
Woman driver.
Aug 26, 2019, 08:51 AM
Space Coast USA
hoppy's Avatar
Quote:
Originally Posted by goldguy
Woman driver.
I'm curious as to the circumstances of the "foam snap like a twig" incident. The only time I've had a paper covered foam structure break is when I lowered the garage door on my Waco biplane.
Aug 26, 2019, 12:52 PM
Retired CAD guy
birdofplay's Avatar
You have an RC flying Garage door ? ! WoooooW ! ;>}
Aug 27, 2019, 09:02 AM
Space Coast USA
hoppy's Avatar
Not once but twice..... I was heart broken each time. It' the plane in my avatar.
Aug 27, 2019, 11:14 AM
Registered User
You should try water based polyurethane over fiberglass cloth.

Its light , durable and very easy to do.

Probably not quite as strong as epoxy though.
Aug 27, 2019, 11:42 AM
flyin' fool
goldguy's Avatar
I've seen the failure on landings twice and once in the air. All cases involved the wings snapping in half, twice from impact and once from stress.
Aug 27, 2019, 11:45 AM
flyin' fool
goldguy's Avatar
These birds are all covered with laminating film …………………..

Transfer beach Combat (4 min 18 sec)


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