plaster of paris and sculptamold, whats the diffrance?

Discussion in 'Getting Started' started by ozzy, Dec 18, 2006.

  1. ozzy

    ozzy Active Member

    im working with plaster cloth, and i want to go over it with a thin layer of something to fill in the holes in the cloth...

    witch is the best and why?
  2. Biased turkey

    Biased turkey Active Member

    Go with Scuptamold , it's a mixture of paper and plaster ( papier-mâché ).
    It's good at covering "the ribs " on the plaster cloth, and it's easy to work with.
    The best stuff since the invention of sliced bread .
  3. nkp174

    nkp174 Active Member

    I would avoid plaster of paris like the plague. Every mountain my dad built with it we eventually had to replace with hydrocal. The plaster of paris was heavier, weaker, and had a nack for forming air bubbles.
  4. TrainNut

    TrainNut Ditat Deus

    I use wall joint compound from the home improvement store to cover my plaster cloth. It's affordable, pre-mixed to a perfect consistency, comes in it's own sealable container, stays mixed perfectly for months on end, takes paint well & drys into a nice hard shell.
  5. Biased turkey

    Biased turkey Active Member

    Doesn't it shrink ?
  6. TrainNut

    TrainNut Ditat Deus

    If you cake it on real thick, yes, you get shrinkage cracks. However,
    1. when applying it to plaster cloth, I apply it with my index finger and only apply the thinnest coat I can get away with while still removing the visible evidence that there is plaster cloth underneath. I've seen others use paintbrushes to apply it.
    2. If you do have to cake it on real thick and it does crack, come back after it has dried and apply a minimal second coat to fill in the cracks.
    3. Sometimes I intentionally cake it on where roads go becuase the shrinkage cracks look perfect after it dries and the roads have been painted.
    Check out any of the layouts in my signature. They have all been done using this method.
    The exact description and name of the stuff I have been using is -
    White container with green lettering, green lid and red horizontal stripes.

    USG Sheetrock Brand
    All Purpose
    Joint Compound

    This particular container is 12 lbs. and it should take me quite a while to use it all. If however, you leave the lid off while working for a while, it will tend to dry out leaving you with some yucko unworkable stuff.
  7. yellowlynn

    yellowlynn Member

    I have used that pre-mixed joint compound quite a bit. I have used a small container, put in a nominal amount of compound, added a tad of water to mix to the desired consistancy, then put in some Hobby Lobby acrylic paint to the desired color. Then it is easy to just smear on, or paint on if thin enough. I will say this, tho, it takes a mite longer to dry hard, but has worked good for me.

  8. dr.5euss

    dr.5euss Member

    I used undercoat plaster. It's cheap and you can buy it in small bags. Filler plaster's good to :D

  9. Great idea joint compound. My brief encounter with plaster and hydrocal is that plaster appeared not to be real white. That made it difficult when I color rocks to look like granit.
  10. Climax1880

    Climax1880 Member

    Just finished doing a stretch of scenery on my layout which has plenty of hills, a river channel and some steep bluffs. I started with carved foam and covered it with plaster cloth. After the plaster cloth dried I got out my "old" bucket of joint compound, added a litle water and got out a paint brush. The compound readily covers the holes in the plaster and dries to a nice smooth finish which takes paint very well. When finished, add about 1/8" of water and reseal the cover. Keeps for a long time.


    Short line steam still lives.
  11. stripes

    stripes Member

    Joint compound

    You can use that same recipe to make stucco coating for buildings! Just brush on several coats (waiting for it to dry between coats) Then you can sand and paint to desired texture!
  12. nachoman

    nachoman Guest

    I've used plaster of paris before, and have had decent success. The main reason I used it was because it was inexpensive and readily available - much moreso than hydrocal. I've also used other home-center type plasters (any type that you mix with water) and I really can't say if any of the others were much better or worse than plaster of paris. The main drawback I saw to POP was working time. From the time you mix it up to the time it is no longer workable may be just 5-10 minutes. I've used other platsters made for wallboard repair that have a longer working time - maybe up to 20 minutes - but still not great. POP is about all I see in the home-center anymore that isn't pre-mixed. The pre-mixed stuff dries rather than chemically cures, and the finished product is much softer - sometimes too soft for layout applications.


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