# Hydrocal vs Plaster of Paris



## tkruger (Jan 18, 2009)

I am still building my layout. In preparation for doing scenery I am testing out some Woodland Scenic rock molds I won cheep on EBay. I purchased a 1/2 gallon of WS Hydrocal for $6.49 at Hobby Lobby with a coupon. If I need allot of this stuff I see that Plaster of Paris is far cheaper by the bucket than the other, especially if it is not on sale or does not have a coupon.

Other than price what is the real difference? I have been told Hydrocal is lighter and sets faster. How much lighter is it? Is it more durable? Will the two color the same?


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## DonR (Oct 18, 2012)

I've used both, they do a good job but messy to handle.

Lately, I've tried drywall patch compound. It's premixed and comes in
various size containers. Easier to work with and not
as much to clean up.

Don


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## dannyrandomstate (Jan 1, 2012)

I used pop in the molds with no problems. The only issue I had was one rock had some small bubbles in the rock face. I just whittled the bubbles a little and it couldn't be noticed. For the price pop is the way to go.

The next time I use it I'm going to try coloring the pop with craft paints. So that way if it does chip or break the coloring won't be an issue.


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## gunrunnerjohn (Nov 10, 2010)

We use drywall compound, cheap and easy to use. We mix it as needed, it's a lot cheaper in the dry form, and it keeps forever.


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## tkruger (Jan 18, 2009)

gunrunnerjohn said:


> We use drywall compound, cheap and easy to use. We mix it as needed, it's a lot cheaper in the dry form, and it keeps forever.


I had not thought of using that in the molds. Just the everyday powdered stuff? Any set ration of water to mix work best or 'Till it looks good'?


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## gunrunnerjohn (Nov 10, 2010)

Depends on what you're doing with it. Sometimes you want to mix it somewhat watery for sealing, other times you want it like mud for thicker applications. Most of the mountains and tunnels on our modular layout are done with 2" foam covered with drywall compound.

This bridge was made using 2" foam as the base (with some wood for strength) and and all drywall cement carved by hand.


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## The New Guy (Mar 11, 2012)

similar to drywall compound, structo-lite is a good choice for ground cover. It contains perlite, giving it a rougher finished surface than typical joint compounds. 50 pound bags run about 12 to 15 bucks.


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## gunrunnerjohn (Nov 10, 2010)

Looks like it would work very similar to the drywall compound. I like the idea of the rougher texture, we have to work to get that.


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