Hills and tunnels - best material.

[bulleidboy]

I've been thinking about it for sometime, but when I get back from holiday I want to rebuild my scenic break hill/tunnel. The current one is virtually flat on top. I'd rather not use the usual cheap insulation foam as the stuff gets everywhere when carving. I wondered whether Celutex/Kingspan(?), which appears to have denser foam would be better to cut and carve - any ideas.

[Steve M]

I can’t comment on Celutex as I have not used it for scenery. However, I have it as insulation in the shed and the bits that came off struck me as being a bit powdery - I suspect it may just make a different type of mess.

This may not be helpful but there is/was a type of pink insulation foam sold a few years ago that carves easily with a hotwire and can be shaped with a Surform rasp - still makes a mess but easier to vacuum up. If you can find it, that would be the one I would use.

Regrettably, I’ve not seen any on sale for a while so now I use a grey expanded foam, marketed under the name Jablac. Again easy to carve with a hotwire but not recommended for sanding. I find it can be shaped into gentle curves by taking thin slivers off the main bulk.

And in all cases I encase the whole lot in plaster bandage.

[brian1951]

Very true BB, polystyrene is messy to use, celutex/kingspan is better mess wise and sturdy, you can cut and shape it better too, i add modroc after, i have done more hills than in the sound of music with this system. For the more frugal people on a tight budget, newspaper crunched up and modroc on top works well.

[bulleidboy]

Thanks Steve and Brian. I realise there will be some mess, but the polystyrene balls that drop off and stick to everything when carving I can't cope with. I'll make the next one in the garage - looks like a trip to Wickes. Barry

[Mountain Goat]

In the past my hills have been formed from strips of paper layed onto card... Not quite paper maché but along those lines. Under that (Though less successful in a way as getting card or paper to stick to it wasn't easy, I used expanding foam).

[Walkingthedog]

I was given some Celotex to play with and is very good. Much nicer than polystyrene. Not easy to get in small amounts though.

Edit. The thinner stuff is available in smaller sheets. My son used 6 inch thick sheets in his house.

[bulleidboy]

I think the Celotex/Kingspan comes in about four different thicknesses - just checked 25,50,75,100 & 120mm. When completed I want to be able to lift the whole thing off the layout. I've been lacking inspiration lately, so this will give me something to concentrate on.

[Walkingthedog]

I was cutting the really thick stuff with a carving knife and there was hardly any mess. Not too bad even with a saw.

[brian1951]

Builders merchants usually have damaged sheets they sell off cheaper, dont worry to much about the thickness as the thinner ones glue together well and are cheaper. If you were closer i have loads left here.

[Steve M]

Barry, many of my hills are made as removable modules. Regardless of which material you choose you can layer the slabs by sticking them together with gorilla glue but be careful as it tends to ooze and drip, so cover things up should you use it.

I roughly carve the separate slabs before glueing - hold the layers together with cocktail sticks while it dries, then shape it how you want to.

As I said earlier, encase the whole lot in plaster bandage and give it a coat of paint (cheap tubes of artists acrylic from the Range). Once you have applied your scenics, and blended them into the surroundings you’ll never see the join and you can still lift it all off for access.