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Foams and Glues


Tim Mackey
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A couple of useful links
 

 
1) EPS = Expanded Poly Styrene. Usually white, and rather fragile in density - like the old ceiling tiles material. Very light weight, and sticks well with PVA, UHU Por, or even hot glue guns with care.

If other peeps would care to add more foam types below, that would be great


Edited By Tim Mackey - Administrator on 15/06/2010 23:46:51

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  • 3 months later...
I've used Evostick for hinging on small EPP models - just chamfer the hingelines, run a thin bead of Evo along each edge and allow to dry as normal, then line up and press the hinge together - hey presto - instant hinge!
 
Depron repairs - I've used greenhouse tape ( a thick clear tape that feels slightly rubbery to the touch) to repair tears and creases in models, in fact my Wildfire is probably 30% tape by now.
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  • 6 months later...
Took two blocks of foam, one Dow blue and the other B&Q pink, both blocks identical size = 48 cu in.
The blue weighed in exactly 5 grams heavier than the pink, there was no appreciable difference in the cutting times etc, the pink appears to be softer and sands to shapeeasier,it is more easily damaged though.
 Blue is also stiffer for a given thickness.
Unless your making a big wing where weight is a critical factor I would go with blue, by the time you have coated pink it will weigh about the same anyway.
 
So, you pays your money and takes your chance with these two,
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  • 4 weeks later...
I designed and built a mid wing sports plane , all out of depron , but entirely held together with Fablon, covered all the surfaces , hinges , the lot, the key is to run a medium hot iron over the fablon,to stick it down properly , BEWARE though once ironed its on for good , just as well cos it makes the depron bomb proof.
 
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  • 1 year later...

@Ashley - Try foam-safe CA as this will soak into the cardboard..

 

I've only used 'Depron' for my builds, mainly cuz it's all thats available at my LMS...

The EPP stuff (looks like old-skool polystyrene) is OK on a pre-made RTF, but not nice to work with.. Too brittle, too crumbly..

Not used Blue foam..

Re Glue.. I use Foam-2-Foam (Like UHU Por) for big bits, and a foam-safe CA for fixing and small bits...

Out of curiosity, I have tested Z-epoxy, and Zap Pink n Green CA's, which immediately melted the foam.. Z-Epoxy was a suprise..!! Also found out the hard way,that CA REMOVER can also melt foam, even if the CA is safe...

PVA works, as in, it doesn't melt it, but it doesn't adhere well to smooth foam..

I've found FibreGlass tape (I think thats whats it's called) useful for placing over the glued in CF spars, just to smooth things out.. Could also work on a LE..

As a cheap alternative to glass cloth, I have tissued one model, and coated it in foam safe dope. Not rock-hard, but certainly more ding-proof.. On a side nore, DONT try tissuing a flat sheet wing, as the shrinking tissue tends to warp the sheet... Trust me.. !! Since found foam-safe spray paint..

My hack, a 150W 6mm depron profile Edge, is now over 12 months old (feels like 3yrs..! )

It's on Mk2 landing gear, but hanging together well.... I've learnt and tested everything on it, including constant landings on a very rough gravel drive. It's just starting to 'micro' crack round the stress points, and requiring the odd bit of CA to fill them, so there's gonna be a day when it's too knackered, but for a £10 airframe, im not complaining..

 

Luv

Chrisie.. xx

Edited By Cyclicscooby on 05/07/2012 12:34:04

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  • 4 months later...

I'm attempting to make as near as I can an indestructible plane for me to learn the inscrutible flying art.

My fuselage is carved from a block of EPE (expanded polyethylene) that I scrounged from the packing area at work (yes I did ask first). This stuff is stupidly durable! You can jump up and down on it! A few of the bubbles migh burst, but it will mostly retain it's original shape. And an RC plane won't suffer that sort of stress, not even with me crashing it!.

I've been using hot glue on it and it's as if I have welded it together. Super strong! I tried UHU POR, wet and tacky/dry methods and could pull the join apart two days later. It's not light weight, but I have cut out the fuse from the underside. A carbon spine of some kind will be required as the flex is hilarious, but it's all part of the deal

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  • 3 years later...
  • 2 months later...

With the mess that HK have made of their web site, which of the multitude of glues available do folk use on Multiplex Elapor?

I have used CA in the past including the MPX own brand glue it really irritates nose and throat despite being used outdoors. UHU POR or similar is not strong enough for securing the carbon rod wing reinforcements and things like horns.

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Posted by Capt Kremen on 04/11/2016 07:39:12:

With the mess that HK have made of their web site, which of the multitude of glues available do folk use on Multiplex Elapor?

I have used CA in the past including the MPX own brand glue it really irritates nose and throat despite being used outdoors. UHU POR or similar is not strong enough for securing the carbon rod wing reinforcements and things like horns.

Not forgetting that we need to wipe any surfaces to be glued with a bit of meths first. I would use carpenter's foaming polyurethane type glues for anything bigger than a control horn. I'm currently using one called Geocel Joiner's Mate that I got from Screwfix. A 500ml bottle costs around £9.50, so it's cheaper that Gorilla Glue and does not expand more than about 100%. Gorilla expands about 500%. Apart from that, any foam safe CA I guess, but I've used Roket Odourless CA almost exclusively, it's relatively expensive, (8.99 from my LMS) but has a 20 second setting time which is very useful. I've always used Bob Smith Industries Foam Safe activator on it. But you can, allegedly, accelerate it with moisture.

Yah, UHU POR is garbage, I find it too flexible and too expensive as a result.

I have used some Maplin Electronics Spray Adhesive. It's cheap and foam safe but remains flexible.

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Hi,

UHU POR is a great glue for depron type foam and i use it almost exclusively their are alternative at craft shops.

Which are also made by UHU,

UHU Creativ Foam Rubber - 33ml,

And UHU Creativ Poly&Foil - 33ml,

Yes it does seem to be a high price but remember that this is a specialist glue and you only need a very thin coat.

And Does get stronger over time.

Steve

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  • 1 month later...
  • 6 months later...

Hi hope this is the correct place.

Just got myself an E-flite carbon Z cub and have a question about gluing on the rudder hinges.

What sort of glue would you recommend for this carbon Z foam ?. The manual does not say, only that damage can be repaired with various glues including regular CA. Never having a foam model before I not sure, does regular CA not eat away this type of foam ?

Thanks in advance for your help.

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  • 2 weeks later...

HI Geo,

Have the hinges come off? Or are you just reinforcing them from new? Whatever the reason, you'll need a foam safe glue. UhU POR or UhU Creative should be fine. Always test a tiny bit of the glue adhesive somewhere inconspicuous, like inside the fuselage.

If the hinge is detached, I would use a thin bead of UHU along both pieces right at the join, allowed to dry, then slide the pieces together with both parts resting on a flat piece of cardboard/balsa/ply/whatever, that way you have the best chance of good alignment. If you mess up, just cut it away and start again. ;¬

Hot glue would also work. For that, I would assemble the hinge with masking tape on one side, then pivot the hinge open a little, towards the masking taped side, run a quick bead of hot glue n there and, before the glue hardens, wipe most of it away with the corner of a piece of scrap foam.

You can see the method at 7:10 in this video https://www.youtube.com/watch?v=DnJ85Sz1iak

Hope that helps.

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The Carbon-Z Cub has mylar hinges pre-fitted to the rudder which need gluing into the slots in the fin.

Geo have another look at the Rudder Installation section (page 9) of the instructions. There is a box at the top of the page which states 'Required Adhesives: Thin CA'.

I'd confirm, as Bob says, that standard CA is suitable, indeed I find it better than foam-safe on the EPP foam used by E-flite. I used thin Zap in the pink bottle which 'wicks' in nicely. Afraid I totally disagree with Chuck Plains.

Great flying model, I'm sure you will enjoy it.

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Ah, points taken gentlemen. Anyone who read my post, please ignore it!!!!!!!!! wink

8lbs ?! That is heavy for a foamie. I did check out a thread on RC Groups, but didn't spot any talk about the nature of the foam.

My only experience with mylar hinges was nearly 4 years ago on an Easy Pigeon glider. They weren't pre-installed and I didn't know what they were, so I used reinforcing tape.

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  • 11 months later...

Anyone know where I can obtain a small quantity of Elapor foam to repair the nose on my 12 year old Twinstar 2 that was involved in a 'Mid Air' crash last week at very high level. The crash was nose to nose with a Radian XL 2.6 M and all the debris was lost in a Jungle adjacent to the flying Field ?

p7070316.jpg

Edited By Mike Etheridge 1 on 10/07/2018 23:34:54

Edited By Mike Etheridge 1 on 10/07/2018 23:39:58

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