Additional casting information needed

Hot glue gun.

Hacksaw blade works nicely.

Taylorra

    I have been busy so hope this gets to you in time. I found cheesecloth or gauze a little too flimsy. Best results have been with drywall mesh, it comes several inches wide or plastic window screen. You will need at least 6 thin coats before putting any mesh and at least the same after. Like paint, more thin coats of latex rather than a few thick ones. Let each dry overnight. Hairdryers produce uneven drying.

     Attaching the walls will depend on what it goes to. Foam boards require special glues and check if they stick to plaster. Hot glue will not work on foam and it is usually too thick. your walls will need a few days to cure if you do decide to glue. I learned that lesson the hard way.

A small coping saw will give excellent cuts. You will be able to cut individual blocks out. Just remember that the plaster is brittle so easy on any pressure.

    The mixing should be straight forward. I used a paper cup about 8 ounces for the blend, maybe 2 powder to one water. Add half the water to the powder and start mixing. As needed add a little more water till you have a melted ice cream mix. If you use a 2 inch blade the mix can be pushed into all parts of the mold. i tried mixing enough for two molds and it started to harden before completely poured. Maybe I am just slow.

You will have to post pics with your progress report. Don't throw the mistakes away. I have plenty and they seem to find homes around the layout. Good Luck

Ray Marion

Ray;  Is 8 ounces right for the wall sections.  I have been using 3 cups  of plaster of paris. Is that anything close to 8 ounces? 

   A friend insisted that I was working too hard to make these castings.  He directed me to get a can of expanding foam as used to seal around window frames, use a wood frame around the mold, use pam as the release agent, and cover the frame with

a wooden cover with a couple of hole to allow for expansion and a very heavy weight

to contain the expanded foam.

   Good thing I had a second mold in production because my friends process produced nothing usable and completely destroyed my mold.  The "foam" that came out through the holes dried into foam mushrooms.  I cut them off to allow me to remove the lid.  The parchment paper I put over the foam to keep it from sticking to the lid had half of the"foam" stuck to it in the form of a sticky mess which looked like partially set contact cement.  The other half of the foam was permanently glued to my mold.  Not a process I will ever try again.

How does Ultimate Scenery compare to Scenic Express? I checked out their website and it was interesting.

Taylorra

     Sorry about your foam experience. It is sticky for all the wrong reasons in our situation. The cup I used is about 8 ounces. The mixing tray will easily hold more but two or three seems to be enough. Slowly add the water. The mix will be loose enough (melted ice cream) to be flowed around the mold. Once you get one right, it will seem easy and you will wonder how you did not get this before.

Ray Marion

Thanks Ray.  My new mold is ready to try out.  Strangest thing!  If I hold the mold up to the light I see pinholes through all the layers.  I would think that a tiny hole in the first layer or any layer would be sealed off by the next layer.  I am going to try the mold tonight.  I'm sure the holes are too small to leak anything.  Going shopping now for 8oz cups, stir sticks and a 2"  putty knife.  Will let you know how it goes.

I found mixing instructions on line which said:  pour water into all the molds you want to cast, pour the water into a mixing bowl.  This will be the exact amount of water needed for your castings.  Add the plaster by sifting it into the water with a hand sifter. Keep adding plaster slowly until a mound of dry plaster about 1 inch high forms on top of the water.  Allow 2 minutes for the water to begin to soak into the mound.

Stir slowly until mixture is of  uniform viscosity.  Pour into mold or molds.  Works GREAT.

Got perfect castings every time.  Last 2 or 3 were problematic because leaks had developed in the mold which made the mold stick to the board it was on.  Would have switched over to my new mold, but it was destroyed by the drastic failure of an attempt recommended by a friend to make castings using aerosol cans of expanding foam to cast with.

That abortion is described earlier in the thread.