THE SMA FORUM ARCHIVE
Posted by Rocketspaceboy, on 2009-11-17 19:40:25
Plaster and Fiberglass for Hills Question?
Mike Brent and Nick H have both mentioned using wood, fiberglass fabric, chicken-wire, and plaster for making hills. This was all in a prior post that I can't find right. Any idea what kind of plaster?
Plaster from the Craft Shop or from the Hardware store. Believe me I've looked at both and I'm leaning toward the Craft Shop variety. But just wanted to double check.
Also, can you believe there are different types of Fiberglass Fabric!?!?!? The stuff I used to use was from a surf shop, then there's the stuff used for bug screens, now I've found a thicker kind that I believe is for shower and bathtub repair I believe.
Let me know if anyone has any suggestions on the Plaster issue.
Posted by Nick H, on 2009-11-17 23:00:01
For a big shape like a rock, hill or full scale tree stump, I use plaster from the plaster shop or hardware store - ordinary casting plaster in 25 kg bags.
I don't use a woven fibreglass fabric, but Chopped Strand Mat. And for plaster, I split the layers - usually I can get two - to help the plaster penetrate better. (See chopped strand mat in my FatRat mouldmaking photos in Making Puppets album at Picturetrail if you're not clear what I mean.)
You can also use hessian (burlap) fabric - loosely woven, not the really tight stuff used for sandbags that doesn't let the sand out. Cut it in strips.
First I make up some profiles of the hill in particle board - I cut curves with a jigsaw. Then I staple the chicken wire onto that, and shape it.
Then dip strips of burlap or fibreglass matting in plaster and lay over the chicken wire. I put 2 or 3 layers on, so I get it strong enough for tiedowns. The top layer is just plaster, stippled and textured as it sets.
Another way to do a hill or tree is to make the shape on the benchtop in water based clay. Then make the plaster shell over that, as if you were making a mould. ( If it's a tree, it's slightly more than half-round, there is no back.) When it's set, turn it over and remove the clay. You might need a few big blocks of clay to have enough, or you may be able to put some bowls upside-down on the workbench first, and put clay over that.
Posted by Strider, on 2009-11-17 23:55:26
I've never done it myself, anything I've ever said about it is from what Nick wrote (so blame him if it doesnt work! ;) :P )
I was thinking (dangerous!) it might work to make forms from big balls of crumpled newspaper and tape, maybe drape a tarp over it (if you can get it to lay right) and then lay your fiberglass stuff over that.
But then, I don't think it would be necessary to make a whole set this way unless your puppets need to run around all over it. You can just make 'trails' where they need to walk and do hills using green towels or fuzzy stuff draped over forms.
Again, never done it! Just read about it. It's like the way Justin did the closing shot for Gerald's Last Day.
Posted by grecodan, on 2009-11-18 00:14:52
You might look for a model train shop. They sell rolls of fabric with plaster imbedded inside. You dip the fabric in a pan of water, then smoosh it down onto your set (or railroad layout, as the case may be), scrunching it up into "hills" and what-not. For backgrounds, it might be an easy way to get your basic shapes in place.
Posted by Nick H, on 2009-11-18 01:40:51
Where I had a van driving along a country road, with rounded hills either side, only the road was solid. The hills were piles of cans and any stuff i had, with a few strips of card laid over to make smooth curves, then I draped dacron fibrefill over the top and sprayed it green. Once the 4 shots I needed were done, I dismantled the hills.
Posted by Strider, on 2009-11-18 01:57:38
Dacron fiberfil!! THAT'S what I was trying to think of!!! 'Fuzzy stuff" indeed!!
Nick, any reason you say fiberglass matt rather than fiberglass cloth?
Posted by Rocketspaceboy, on 2009-11-18 12:30:59
You have plaster shops? :P
Darn, I should have thought about the burlap. The Fiberglass fabric is so tightly woven It looks like I could wear like a shirt. I think though I can pull it loose and get it to loosen to accept the plaster. If that doesn't work I'll just use 4 yards of burlap (my favorite stuff). I'll post a picture in a couple of days. It's supposed to be christmas hills with christmas tress. I'm stuck making foam latex tress for the set as well. Not enough budget for urethane. ;(
Posted by Nick H, on 2009-11-18 15:44:35
Chopped strand is looser and mixes more with the plaster. With the cloth, it's hard for the plaster, which is thicker than resin, to penetrate the cloth - so it can just sit on the surface, and separate later. It can even do that with the chopped strand, which is why I pull the layers apart.
Yes, we have a few shops where tradesmen plasterers go to buy their plasterboard, trowels, bags of plaster, pre-cast ceiling roses and cornices etc.
Posted by Rocketspaceboy, on 2009-11-18 15:52:01
I just purchased the plaster from the craft shop. It's Hydrocal!!!! I could have totally done a one-stop at the local Monster Makeup Store. Now I know.
Wow, I'm going bonkers on this project. I have so many molds and latex castings to get done by tomorrow. Plus build the set by Friday. Can anyone say 10 foam latex trees?!?!?! Ahhhhhhhhh.............. Maybe I'll just make five and fake the rest in the shots.....
Thanks for the help.
Posted by Nick H, on 2009-11-18 16:50:08
Foam latex trees??? Not urethane foam?
Posted by Strider, on 2009-11-18 18:50:56
Huh... I got some fiberglass cloth that's a very open mesh, similar to burlap. I think this kind would work pretty well. More expensive than burlap though. I found it through a site that specializes in different types of fiberglass, and they had a vast selection, so I chose one that looks like plaster (or urethane resin, If I ever decide to try that) would go right through the mesh.
Posted by Rocketspaceboy, on 2009-11-19 11:47:20
Believe me when I say I would prefer Urethane Trees. Come to think of it I might have a little Urethane but not enough to make 10 trees. I might have to make another road trip to get more Urethane. It's just a stupid idea to make them out of Foam. I don't know what I was thinking.