Foams and Glues

[Erfolg]

I ma not sure when i built this model, it is now some years ago, at least 5, I would guess getting on for 10. It is flown normally twice a week.

It is made from Depron, the adhesives used were very conventional. The sheet is held together with PVA. The surface initially roughened with sand paper. Then weighted down.

It was then covered in lightweight glass cloth, using a Water Based Varnish.

The hinge is just the foam cut away, to form a bottom hinge.

It has now suffered two serious crashes over the years, and has been easily repaired.

Obviously the nose.

New wing tip.

The old tip., before repair, after collision with a tree, then falling to the ground.

This model is now also pretty old, made from EPO, when assembled Screwfix No-nonsense Cyno was used.

In recent years it has suffered a lot. The first issue was a wing spar adhesive failing in flight. This appeared to be some form of contact adhesive, possibly similar to UHU POR. Very recently the rear motor broke loose, demolishing a good part of the tail. In this case, the plywood mount had delaminated.

For repairs I have used Gorilla Polyurethane glue. Also copious amounts of Cyno, all the cheap stuff from either Screwfix or Toolstaion. I have found that as an adhesive Gorilla is no better than the other stuff, although massively expensive in comparison. The other side of the coin, is that the shelf live seems to be much greater. Although another club member has said otherwise.

Sadly, EPO seems to have a user life, as various cracks in the foam have appeared, at high stress points around the wing seat corners. Also the adhesives used by the manufacturer are also failing, the body halves separating. It now is incredibly tatty, yet again it keeps on going.

[Engine Doctor]

Posted by Mike Etheridge 1 on 10/07/2018 23:29:46:

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 ?

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

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

Just make a new nose cone from light balsa scrap glued into a block then hollow with a Dremel . Probably easier than working with foam ?

[Erfolg]

I do not think it has been mentioned, that Blue Foam was used to produce wing cores in the dim distant past. In many if not most cases the wing would be covered in "Christmas or Birthday wrapping paper". The adhesive used was generally a cellulose wallpaper paste such as Polycell. This arrangement resulted in a very strong wing. I never saw any fail, even under severe towing or line screaming Bungee launches.

I think Phoenix Wonder Wings 100s was one model intended to use the system.

[Roo Hawkins]

as a builder of large scale gliders in the 4 to 6 meter range I use a lot of foam.pink foam from b&q is not available now for the last 3 years. Dow chemical is also not making blue foam has well.I rang Sheffield insulation and thy only had some in stock at Bedford only. And only 9 sheets so I now have 9 sheets hidden in my workshop. Dow are now doing it in black and sig areally only selling it in orders ? 250only.the building industry are using less of it now.

Edited By Roo Hawkins on 12/07/2018 13:55:02

Edited By Roo Hawkins on 12/07/2018 13:56:56

Edited By Roo Hawkins on 12/07/2018 13:57:50

[ken anderson.]

hello ed,have a look for some of the stuff they use for packing TV's in their box's with....or go down to the local council recycling depots...bet you find some there....

ken anderson....ne….1. recycling dept.

[Erfolg]

It is a great loss that Blue Foam. or "Dow Corning Floor Mate" when I purchased it from Sheffield Insulation, is no longer being sold. Is that the UK or World Wide?

I have repeatably intended getting a sheet, only forgetting to do so. Such a pity

[Robert Cracknell]

Erfolg

 

Try here....**LINK**

or

here...https://www.panelsystems.co.uk/product/floormate?attribute_pa_group=floormate-500a&attribute_pa_product-name=floormate-500a-2&attribute_pa_length=1250&attribute_pa_width=600&attribute_pa_thickness=50&attribute_pa_unit-of-sale=pack-8-brds6m2&attribute_pa_min-order-qty=6&gclid=EAIaIQobChMIiNKN-u6Z3AIVQ7cbCh1EJw-BEAQYAyABEgKMNfD_BwE

Edited By Robert Cracknell on 12/07/2018 16:27:48

[Roo Hawkins]

I know about them it is a minimum order of 6 packs at more than ?100 a pack. Plus they are going to the black stuff.

Edited By Roo Hawkins on 12/07/2018 16:56:35

[Robert Cracknell]

Perhaps you could all group together via the forum to put in a minimum order before it goes....

[Erfolg]

It does seem that the material is available still. I bought was then called X200, which I guess is related to a measure of density.

I think you are correct now that Sheffield Insulation are no longer stockists.

The idea of getting together a number to purchase a pack of sheets is good. The supplier also needs to be local to make the delivery. When i bought my single sheet I had to cut it into half, to get into a a hatch back type configuration.

[Mike Etheridge 1]

ED's balsa solution was one that I favoured , but what about Depron , I have never used or owned it , but does it have similar properties to Elapor foam ?

I was hoping someone had a written off Twinstar or an other Multiplex model ?. Surely Multiplex should be able to provide a quantity of Elapor foam ?

Thanks for the other responses I will have a closer look at them.

[Robert Cracknell]

Jewsons are pretty much countrywide.....

**LINK**

[Erfolg]

Although EPO, which Elapor is in principal, is used extensively in the motor industry, I could not find a UK trade supplier when i wanted to build Foamy Daves Biplane (free RCM&E plan). Some UK model shops did stock the material, though it was priced as if made from gold.

Eds solution works for me, as does Depron. The trouble with Depron, it does not pass any positive comparison with EPO.

Have you thought of using boiling hot water, I did this when my Nitro Models Dornier 335 when it hit terra Firma, which is made from EPO, It regained most of its previous shape. I then filled it with Light weight filler,

[McG 6969]

Hi Mike,

If I'm allowed a point of view, ED's balsa is a good one.

I wouldn't go for Depron in this case as you need to laminate a lot of layers to get a sufficient thickness.

But have a look at Erfolg's nose repair of his pusher jet.

Just a vertical central layer of thin ply to give you a sanding guide, sandwiched by two bits of blue foam. Job's done!

Robert C's advice above could point you in the right direction to get some blue foam as well.

Cheers

Chris

[Mike Etheridge 1]

Repair underway having used the hot water technique recommended to return the Elapor foam to it's original non-compressed shape--it did work !. So far I have added some light balsa to the fuselage fixed with Medium Cyno and filled the gaps with Ronseal wood filler. The sanding process is next and the plane should be ready for flying on Sunday. Thanks again for the advice chaps.

Edited By Mike Etheridge 1 on 13/07/2018 12:08:23

[Mike Etheridge 1]

Finished off with some white tape rather than paint and ready for action and hopefully no 'Mid Airs'.

[PAUL HUTCHINSON 2]

Guy's

HI I'm reasonably new to the forum and I know you have talked about EPO glue a lot, my son was flying his Wot 4 Foam E at the weekend and the ground jumped out in front of him. What is a good glue to use for gluing the fuselage and wings.

Cheers

Paul

[Engine Doctor]

If it's a clean break and you want a quick job then cyano will glue EPO type foams well. If your not sure and you have more time try Deluxe Materials Foam to Foam . Excellent bond but does take a while to dry. There's also UHU Por that will fix all types of foam but beware of Ordinary UHU as it will glue EPO but melt expanded polystyrene.

[perttime]

There's a new(ish) foam sheet in the market, but I doubt there's a UK supplier. Yet? Flexi Foam.

As the name suggests, it is bendy. Apparently more rigid than EPP of the same thickness, though. It comes in a few different thicknesses from 1mm to 10mm.

I ordered a box of ten 100x30cm size 3mm sheets from Germany. Just first impressions: the surface is very smooth for foam. It does not break when you fold it. For a flat structure, it needs something to add rigidity. The main supplier sells flat foamies that have flat carbon strips for that. Bent into a tube shape, the tube is quite rigid, so it should be great for a rounded fuselage skin, for example.

This is apparently the same PP foam that Graupner marketed for a while as Vector Board.

The German source: **LINK** The site is in German but Google Translate should make sense of it.

With shipping, it isn't exactly cheap. Don't know if lower cost shipping can be worked out if you order multiple boxes.