Scratchbuilt terrain from plant containers & diy silicon gaming mats

[Munindk]

I've had expansion foam wreck food packing containers, unaltered ones at that, so I'd be worried that it would tear your lovely creations apart.
You could pick your least favorite building as a test piece?

Would plaster work as a filler?
I know it releases heat when it dries, but I dont know how much.

[zrunelord]

Still have to experiment. I have already done stuff with small amounts of foam on
other stuff so I think it is doable.

Plaster of Paris is good as a filler but heavy ( you can decrease the weight & volume by putting
small pieces of foam in it whilst still wet ) and very fragile ( you can add strength to it by mixing 1 part
white cement to 3 parts plaster but it will still break )

You can use resin but it will warp the thin plastic due to heat and it is heavy ( you might use foam infill as above ).

Exp Foam is the way to go. I will post pics as soon as I try it out.

Z

[Maniac]

If you leave the open end of the piece up and insert the foam, you will be less likely to get warping of the plastic, although it can still happen if the plastic is thin or not constrained.

That will, of course, necessitate the need to saw off the excess foam.

What about a reinforcing interior structure.?  I've done this for some paper terrain using cardboard, foam core, and just plain foam.  All of it works well to improve structural support.



Even something as simple as cross beams will do a lot to help (i.e. run some crossbeams/spars from the middle of one side to the other).

[Munindk]

Paper mache could work, but its messy and slow compared to foam.

[zrunelord]

Yes off course Maniac,
when I mentioned bulwarks I was referring to card cross beam supports.
I use that frequently on my card builds to strengthen the general shape/form.
It does add weight but not that much. Unfortunately a structural build like this
will only be as strong as the outside material , though it is possible to shore up the
wall thickness with small square pieces of card & pva.

And that was the way I was planning it , to have the foam go up so less
pressure, my main concern is what effect will the solvent in exp foam have
on the very thin plastic, keeping in mind they are very flimsy egg plastic cartons.

Grey undercoat spray can has had no effect on the plastic & that is solvent based.

Another possibility would be to make moulds but that is costly & time consuming
considering that egg cartons cost next to nothing.

Munindk, papier mache might be another possibility especially if mixed with pva.

Thanks all for the feedback
More to come.
Z

[CookAndrewB]

Probably just as easy to panel the piece on the interior, as mentioned, and then potentially brace those panels with card or popsicle sticks. You wouldn't have to be overly exact with any of the interior since it wouldn't be seen, and it would solve all but the hardest of blows to the terrain. I have some thin plastic container terrain like this and I didn't brace any of it. By the time it got primed, painted and sealed I generally felt like it was substantial enough to call it a day. For larger pieces I think I would try foam just to be on the safe side.

[Braz]

If have extras left, just stack a few one on top of the other. Usually they are designed to stack one on top of the other snuggly. The multiple layers should stiffen it up especially if add glue. Usually this lifts it up so you may need to trim it or add some trim to the bottom edge.

[Munindk]

Munindk, papier mache might be another possibility especially if mixed with pva.

You might be able to make a papier mache "porridge" from and just pour it into the buildings.

Sorry about all the posts about such a small detail of your lovely build, but I'm very interested in easy ways of strengthening flimsy structeres as I've a bunch of half finished projects, and I have issues with expansion foam (its very toxic, unpredictable, absorbs moisture).

[Maniac]

Oh, and I forgot to note, to weight down a piece you can glue washers or nuts to the inside/bottom of the structure.  You could glue a couple to the bottom of walls if you don't have a base.  A 1.5" or 2" fender washer adds some nice heft.

I did this on the bottom panel of some of the infinity boxes/crates, and it works great.

[zrunelord]

Ok ....one by one

Maniac .. good idea washers would be useful.

Munindk... no need to say sorry my friend, once I used the paper left over from punch machines, the ones that are used for binding A4 documents. Mix all the little bits with pva & you have papier mache. If mixed with black or grey paint will make great rubble piles. I also mixed them with resin to good effect.
Exp foam is indeed toxic but small amounts such as this should not cause problems ( unless you get it on your hair or on your wife's/mother's favourite sofa  )

Braz - some of them have carton halves glued on the inside. This will come out once I undercoat them ( soonish )

Cook - I am clumsy & frequently drop things  . They will break eventually. Bracing them with card will help,

Will post pics asap.
Z