Let me quote the article from the April, 2010 issue of MR in an article on page52 about Don Shook’s BEAUTIFULLY done layout:
“He then placed Hydrocal-coated cloth over the screen and added more Hydrocal to build up the scenery contours. After priming this basic scenery with clear sealer, he then painted it using latex paint.”
Why do you think he sealed it?
thanks - walt
I’ve never used/needed sealer for general scenery applications. It could be handy when using initially-liquid products to model water, however.
Mark
There are those who feel you need to seal Hydrocal before painting weather it be hard shell scenery, rock out cropping’s, buildings or one of my latest projects a Hydrocal stone viaduct bridge. It’s my o/p when you seal Hydrocal you have succeeded in eliminating the very thing that makes Hydrocal worth using. It ability to show very fine detail. This picture really doesn’t do the model justice in regards to showing all of the stone work details, but you at least get the idea.
The gentlemen who manufactured the bridge taught me a neat trick, before staining hydrocal aka making up a diluted paint wash you first spray the hydrocal with some wet water. By introducing the moisture to the Hydrocal first you eliminate the absorption effect that dry Hydrocal will have. If you don’t hit it with the wet water it will soak up paint or stain like a sponge requiring you to use far more paint/stain then you should have.
Hydrocal and plaster absorb paints, often not evenly. That can leave blotches of lighter and darker colors. Once sealed, absorbtion is no longer a problem.
On the other hand, once sealed, you have to paint in all the details that you want. You can’t use washes effectively, since there’s nothing for them to cling to. Paint also has a tendency to fill up the tiny details.
It all depends on the effect you’re going for.
2-6-6-6: I think you answered why he sealed it within your reply when you said “By introducing the moisture to the Hydrocal first you eliminate the absorption effect that dry Hydrocal will have. If you don’t hit it with the wet water it will soak up paint or stain like a sponge requiring you to use far more paint/stain then you should have.”
dgwinup: which is what you said!
I haven’t worked with Hydrocal, just plaster. And I agree that I like the varied look that varying absorption provides. But his layout was so beautifully and artistically done that I figured sealing was some sort of trick that advanced scenery guys used.
Thanks for taking the time to answer my question.
Personally, I like the fact that hydrocal soaks up water-based paints unevenly. The only place I might not want that effect is on a structure where I want the paint to look even and perfect. For landscape items – especially rock faces – blotchy is good.