Problem - cracking Gypsolite

[mrnimble]

I'm trying to use SE's Gypsolite and now find that it is cracking after 24 hrs.   I am mixing it according to instructions (for "Thicker Compound") and applying it in relatively thin layers like putty or a coat of plaster over SE's Plaster Wrap that has dried for a couple of days (had to do yard work).  Consistency is good, like a plaster, and working time is as advertised. Any suggestions before I continue?  I thought cracking only occured with thick coats of plaster-of-paris or drywall joint compound.

[jeffrey-wimberly]

I had the same problem with drywall compound that I put down for my scenery base. I filled in the cracks with a thin mix of plaster of paris.

[Grampys Trains]

Hi mrnimble: I've had pretty good luck mixing some Sculptamold with Gypsolite.  Another thing you could try, spray a mist of water on the dried plaster wrap, then apply Gypsolite.  It could be that the plaster wrap is drawing the moisture out of the Gypsolite and it's setting too fast.  Just a thought.  Good luck!

[MisterBeasley]

The cracks give it character.  Like wrinkles in old model railroaders.

Once you paint and apply turf and ground foam, you'll never see the cracks.  You might try mixing with a bit more water next time, to see if that makes a difference.  But it doesn't really matter.  Mine cracks all the time, and I'm always happy with the end result.

[fireman216]

I have never had Gypsolite crack...I always add a little white glue to the mix....

[mrnimble]

I see two shortcomings here:  1. I didn't pre-moisten the plater cloth first, and 2. I didn't add in as much white glue as called for, mainly because I was short on Elmers from constructing the benchwork.  I'll pre-moisten and add some more glue when applying the next batch and see what happens.  Thanks.

[Grampys Trains]

Hi mrnibblw:  In reading some of the replies to your post, it got me thinking.  I haven't used glue, but maybe some sort of glue is one of the ingredients in Sculptamold.  I do know that, by itself, it is very sticky.  Just my opinion.  Good luck with your scenery.

[larak]

This is almost certainly a case of the gypsolite drying too quickly. Most probably because the underlying plaster absorbed the water from it. I use structolite (a very similar product) in various thicknesses and have never had a crack. Always moisten any adjacent hydrophilic material before applying the plaster or plaster mix like these brown coats. That holds true for bricks and mortar too. you should NOT need glue but what the heck, if you have extra use it up. It shouldn't hurt either.

Karl