foam casting

[Munkey Joe]

OK well My FLGC has a love for the German company Ziterdes. you can find them here:. NOW with the current prices, and my general desire to spend loads of money I turn to you guys, the casters.

I have no problems sculpting my own terrain but Im not too sure about casting on foam. I have seen many foam terrains coming out of the woodworks now (MAS and ziterdes are but 2 companies) that are turning out this dense lightweight foam terrain. It has to be cheaper than resin as the parts are cheaper, and the weight is almost non existent. This would make fabulous terrain IF I coulod find some way to make it. Buying it is just too much cash, as I am the major moneybags of the club and times are tough to buy but not make.

Does anyone have experience, input, ideas, or anything like this? I have seen tuts up on reaper and other places () but they really dont have the same detail im looking for.

Thanks for your input in advance!!
Tommy

[blind pig]

Expanding polyurethane foam works really well for scenery.

Couple of things I've found is you need really thick moulds or be able to reinforce the mould in something like an MDF (wood) box; otherwise, your mould will distort, possibly rip and the terrain piece will be useless.

It takes a bit of faffing about, but you should use the minimum amount of expanding resin as possible to just fill the mould and no more, too much and you risk buggering up the casting.

Slush casting polyurethane foams is the way to go. Have the mould and its' strengthening box ready, pour the foam when it just starts to "cream" into the mould and rotate the whole mould, coating all the inside detail. This will ensure there are no airbubbles against the surface of the final object and that the foam expands inwards. Just leaving foam to expand on its' own will make less than pleasing results with a honeycomb like surface and airbubbles.

Use a high density foam for strength.

Sanding expanding polyurethane foam will expose the honeycomb interior and will ruin the finish.

Foam is MUCH cheaper than using resin! I have a Plasma Pistol Boss that uses nearly 1KG of resin to fill or less than 90 grams of expanding foam to fill. The expanding foam is really strong and light weight, and there is no advantage in using resin for this job.

Another use of foam is as an internal strengthener. Rotocast or slush cast objects using an appropriate polyurethane resin can later be filled with CAREFULLY measured amount of expanding foam (better yet, under fill it and top-up later) and strengthened. This technique uses expensive rotocasting resin to get a perfect outer layer or resin that can be sanded and the much cheaper and lighter expanding polyurethane resin to fill the majority of the mould.

My Plasma Pistol in expamding foam:
viewtopic.php?f=19&t=223

[Munkey Joe]

Nice. Thanks for the reply.

I dont know if I have access to Barnes products in the US but how would one of the smooth on products work?? OR Aeromarine??

Smooth on:
Aeromarine:

I understand the need to reinforce the molds with expanding. I also saw the reaper thread about foam mountains () but lack the detail you got and I would like.

Here is some sample pics of popular terrain I would like to produce myself.:

We currently own these pieces (not my pics though) and I am wishing to make similar pieces and mold and cast as these get broken/destroyed. I did this for my blast craters and cast in plaster and it has worked great. I would like to have something "lighter" though...

Thanks for your input BP and I think I just need to buckle down and pic some up and try..... I will accept any recommendations on the product i have available in the States though.... I put those links up in the begining as I Know they deliver to my home and I am familiar with their company.

[paulson games]

At Adepticon last year I got a chance to talk to some of the guys who make the battlefield in a box terrain for Gale Force 9 which is a good deal (also comes prepainted)

They use foam to cut the weight and costs on their terrain. They use an outer shell of resin and then fill the bulk with an expandable foam.

They use a single sided mold, then pour a quick curing resin into it. They keep rotating the mold so that the resin evenly coats the surface of the mold. They keep it continually moving simular to gravity casting and teh result is a hollow resin shell with a high grade of surface detail as per normal resin casts.

Then they use a low expanding foam to fill the body cavity of the terrain and use a paint scraper/skimmer to swipe across the top to make the surface level.

Smaller pieces of terrain like tank traps they use solid resin, but larger stuff like hills and thick castle walls they use the hollow resin with foam core.

You want to use low expanding foam as it exerts less pressure on the shell or molds. Regular expanding foam will push too much and it has a lot of strength behind it when expanding which is really problematic as most molds can't hold up it it and will tear or distort so badly the casts won't be usable. So you want to preferably stick with the hand mixed foam, or the low expansion cans but thr hand mixed is the optimal choice.


I always give smooth-on a big thumbs up. MIcromark has foam filler micro beads which can be mixed into the resin which dramtically cuts the weight down. I haven't really looked for them on smooth-on but I'm sure they have something simular.

The plaster for the Hirst Arts stuff works well but it's incredibly heavy and chips fairly easy. Resin is significantly lighter a bit more durable although it can warp in heat. On larger pieces teh foam core will save a lot of costs and weight but you do have to be a bit more gentle with it as it can warp or crush inwards if handled roughly as the air pockets in the foam aren't as durable as solid material..

[blind pig]

[Munkey Joe]

Awesome guys (Girl!!).

Quick question..... While I am "rolling" my mold, do I do this till it turns to syrup or cures, or do I do it till I have hit all the parts and then just let it cure up as normal??

This might be one in the same, as I find I typically have a short time till I "bloom"...

[blind pig]

[Munkey Joe]

[mangozac]

If you're gonna sit there rolling it for 20 mins I don't see why not

[blind pig]