Hydrocal vs ultracal vs supplier?

John, it is my understanding that the main use of Hydrocal because it does not shrink was for dentist to make impressions of teeth. 

Sounds like you have an inside track on a supplier.

Happy railroading,

Don

John,

Plaster products are always cheaper by the original large bag, usually about 50 lb. The repackaged material in hobby shops is for the convenience of modelers who don't need such large amounts.

Check the video posted on your other thread. In it, Dave Frary explains that Hydrocal and similar products are fast setting and good for rock castings. Slower setting materials such as Gypsolite or Structolite are more convenient and will produce less waste when covering large areas of scenery.

Jim

Wondering if I should order fast set or regular?

John,

The regular sets plenty fast enough (within 5 - 10 minutes or so). It keeps you on your toes to work fast when filling rock molds.

The extra fast might be so fast as to be unworkable in modeling. Good for making dental impressions since most patients lack patience, as I'm sure you know well!  --but I'm guessing too fast to mix enough to fill a big mold.

I'd definitely go with the regular.

Jim

Hi John,

I have made a few things with plaster, like USG hydrostone. Most of my

 scenery and viaduct cast from it. Mold pre when casting inportant,

need to be clean and spray with soapy water just before casting. The hydro

stone gives me 10-15 min work time then hard in 1 hour and can demolded.

I make my own rock molds or buy from bragadon, latex molds. As you see in pictures

wood frame cover in wire, then burlap cover in wet plaster. Then add rock details

fill in gaps with a speciel easy to carve foam I found in insulation industry. I sell

this foam to. Then using dry wall compound found at HomeDepot to fill, shape, and

sand to affect. I like having time to work with the slower stuff then simply put a

fan on area to excelarate set time. Move to another area and press on. It takes

time but the results are very real and impressive.

I have many technicz, call me.

 Bob   AltoonaModelWorks

Quite the layout, dude.  How about I visit one day....

Any time John