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Plaster rocks

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  • Member since
    November 2007
  • 1,089 posts
Posted by BlueHillsCPR on Wednesday, January 21, 2009 7:26 PM

The rock work all looks really good and I can't tell the plaster from the sculptamold, from the hydrocal, etc.

In regards to cost, I have heard that Hydrocal, if purchased in a large sack from a building supply company is much cheaper than when purchased in boxes through a hobby or craft shop.  I haven't tested that theory myself though.

  • Member since
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  • From: Weymouth, Ma.
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Posted by bogp40 on Wednesday, January 21, 2009 6:43 PM

I tend to have the best results using Hydrocal. Whether casting a production mold or custom, using Hydrocal has allowed me the most versitility for cutting, carving or curving the final result. I will always color the plaster with powdered masonry dyes to eliminate any white chipping to show from any future abuse.

This spot was done with simple molds for pouring the stepped sheets, cut, carved sanded for fit

Fitting of the pieces

Finished area

This spot was done w/ Woodland Scenics production molds

Mant times slabs of colored Hydrocal are used as starting stock to rip/ cut on a bandsaw and glue in place for retaining walls, pilasters and caps.

Wetting the dried plaster allows for ease of shaping or carving.

Modeling B&O- Chessie  Bob K.  www.ssmrc.org

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  • From: US
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Posted by jacon12 on Wednesday, January 21, 2009 7:24 AM
With all due respect to Art, Tom, Don and Mr. B.... they all look great! :)
 HO Scale DCC Modeler of 1950, give or take 30 years.
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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Wednesday, January 21, 2009 6:59 AM

With all due respect to my buddies Don, Tom and Art, I like Hydrocal.  The very fine grain brings out the details of the mold.  That's not such a big deal with the low-resolution Woodland Scenics molds, but this one is from Dave Frary.  Just to be difficult, I waited until the Hydrocal was almost set up, and then curved the mold around a form to get a curved wall:

After cutting down the casting, painting and weathering, I ended up with this"

More recently, though, I've started using Bragdon Foam.  This isn't a great picture, but I'm really impressed by the quality of the castings you get from this process:

Bragdon Foam is a 2-part resin mix.  It's very labor-intensive, unfortunately, but the results are very good.  The Bragdon molds themselves are very high quality, and the casting resin brings out all the small details.  www.bragdonent.com if you want to check their web site.

 

It takes an iron man to play with a toy iron horse. 

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  • From: Austin, TX
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Posted by Don Z on Tuesday, January 20, 2009 11:59 PM

With all due respect to my buddy Tom, I prefer to use White Art plaster. It dries to a pure white color and has a much finer finish texture compared to Plaster of Paris. It also takes washes of color very nicely, can be carved once applied and it sets in a moderate amount of time. Here is an example of my rockwork that was created with homemade latex molds:

Don Z.

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  • From: Carmichael, CA
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Posted by twhite on Tuesday, January 20, 2009 11:22 PM

Actually, and with all due respect to my buddy Art, Sculptamold can be used well in rock molds.  The trick is to mix it 50/50 with water, making it a 'soupy' mixture, then pouring it into the molds.  It has to set longer in the molds than plaster or Hydrocal, but during that time, the plaster grit that makes up part of the Sculptamold mix itself, settles into the mold crevices.  It's a slower method than plaster or hydrocal, but I use it out here in California, because the dry climate in my area makes Hydrocal set up way too fast, and Plaster of Paris turns out to be too heavy for what I need.  Sculptamold, being a maiche type material is lighter than plaster, just a little heavier than Hydrocal, and takes enough time to set up that after you've pressed the mold into the portion you're working on and peeled it off (total time from pouring to pressing to peeling is about 25 minutes) you have a nice gritty texture that will take additional carving very well. 

Here's part of the Sierra Buttes I'm working on.  95% of what you see is from Sculptamold castings blended with Cripplebush rocks. 

I like Sculptamold. 

Tom Smile

 

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  • From: New Brighton, MN
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Posted by ARTHILL on Tuesday, January 20, 2009 8:39 PM

I use Plaster of Paris. It is cheaper than Hydrocal and I like the texture. I have not tried Sculptamold because I couldn't imagine it working well.  Seeing I am now carving most of my rocks out of styrofoam, I will stick with P of P for what I do.

If you think you have it right, your standards are too low. my photos http://s12.photobucket.com/albums/a235/ARTHILL/ Art
  • Member since
    January 2009
  • 47 posts
Plaster rocks
Posted by SD Fan on Tuesday, January 20, 2009 8:04 PM

What would be better to make plaster rocks out of  those woodland scenics molds, hydrocal or scuptamold?

The only thing we have to fear is fear itself, or maybe ballasting some track.

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