Sealant for Hirstarts flooring

I bought the hirstarts.com mold for making a large (huge) stone floor for my mordheim board. My wife and I have been casting out of lightweight hydrocal (gypsum plaster). Generally this stuff has proven very strong in the past for making figure bases and stuff.

My question is this, normally (for train layouts) i use pigments on hydrocal castings like rocks and stuff then i paint it with white glue to act as a lacqer/sealant and make it look more like rocks. I think the white glue might become tacky or sticky from all of the handling inherent in playing mordheim.

What is the best stuff to use as a sealant of the plaster after it is glued onto the mordheim board?

Thanks for your help.

If your not worried about the plaster chipping then any varnish/dullcoat spray should work once it's painted. I've made a few buildings and my biggest problem is chipping (cheap plaster). Otherwise the plaster soaks up a lot of paint and I've never has a problem with it rubbing off. Since the first couple coats soak in 1-2 millimeters.

actually i am worried about it chipping. hydrocal is strong but it will still need a fairly thick layer of some type of sealant. What brand of sealant works well? definitely will not paint the hydrocal - we were planning only to use model railroad pigments to stain the plaster before applying sealant. What brand does any one recommend?

I don't think that any sealant is going to help much with chipping. It would have to be a real thick coat, like the varnish on a table. How about using color in the plaster mix, since you aren't going to paint it. That way if it ever chips it's the same color all the way through and you'll never notice it. I don't know the exact name, like a concrete dye or something like that. I'm pretty sure there's mention of it on the Hirst website. Probably in the painting section.

I would try using a coat of watered down PVA first, followed by a coat of exterior gloss varnish and finally a coat of matt varnish, such asTestors Dullcote. Make sure you allow at least 24 hours in between coats to allow them to harden. That should leave you with a very tough, gloss free finish.

thanks for the recommendations

would mixing pva into the plaster make it stronger ? I'm not sure how this would effect the plaster to water ratio it probably depends on how gloopy your pva is.