Has anyone used a thin layer (1/4" or less) of latex caulk instead of plaster in rock or retaining wall molds to create detailed and durable castings for a portable layout?
I need to build an HO curved retaining wall and a stone arch bridge on a portable layout. Detail, durability, and weight are considerations.
Using armour all as a release agent in my latex mold and spreading the caulk thin with a piece of ice to prevent sticking produced a usable result. I don’t think I can get the detail casting in foam or I would use that. Does anyone have tips on using latex cault for castings?
I have a feeling that you may be the expert, as this is the first time that I’ve heard this suggested. [swg] However, if you’d rather have the casting in foam, why not get a can of that spray foam insulation? While it’s sometimes difficult to predict its amount of expansion, a little practice should overcome that obstacle.
I briefly experimented with latex caulk and used rocks as my molds. I didn’t work very well. The detail didn’t translate into the thick caulk and there were a lot of bubbles. Also, dried latex doesn’t accept paint washes nearly as well as plaster does.
Perhaps rigid (pink or blue) foam would work better? It might lack a bit of durability, but it’s lightweight and you can easily carve it.
Hydrocal plaster might also work. It’s lighter and stronger than conventional plaster of Paris, and will accept paint washes.
Thanks to all for the help so far. the attached link shows the practice efforts so far and hope somebody with more talent will give it a try. I was thinking of making a wall out of extruded foam pieces and casting it in the latex caulk. this practice piece with the caulk is just to show it can be done. I agree it won’t take a wash and these things are going to need a lot of painting to look right. But the caulk won’t chip or crack if I move the layout around and it is very easy to add to a curved situation.
Have you tried a thin layer of sculptamold or structolyte/gypsolyte and carving it? I have a cut through foam that I was going to do a thin plaster or hydrocal casting in a tinfoil mold, but I’ve seen some comments that make me think I could just butter on a layer and carve it a little. I suppose a little depends on the type of rock you want to model.
If I read your post correctly you using latex caulk as the actual molding agent, which by the looks of your blog seems to have given you good results but two things if I may. I would not use Amoral as a release agent as I am not sure if the presence of Amoral will have any after effects on the silicone, I use simple wet water as a release agent maybe a little more soap then normal but it works fine. Also I believe you can by casting resin of a silicone nature in bulk a lot cheaper then silicone caulk and it may have better pouring qualities then silicone caulk, but hey if your happy with the results thats all that matters.
you are correct I used the latex caulk as the casting agent not the mold. i spray the armor all in there and let it dry to put a thin film of silicone between the natural latex mold and the latex caulk. Can’t hurt to try doing it with wet water. Thanks.
As to the cost, the flexible stone walls from Scenic Express recommended above look great, but i would need enough walls and castings that the cost is high. The tubes of caulk are $2-3 at Walmart and I think I can make about 4’ of retaining wall per tube. So far I am not finding any casting materials that are going to let me wrap up my job for <$20
The fact that nobody has used this method doesn’t seem to bode well for me carrying it out to a successful completion. I’m going to cast a few more walls and rocks and see how they look painted.
Don’t sell yourself shot, just because someone else hasn’t done it yet doesn’t mean your idea is without merit. After all one person had to be the source of every good idea right. My only reservation would be with using caulking is will it ever dry completely or will it remain soft and pliable therefore breaking down over time. Only one way to find out I guess.After all guys have been using clear silicone for a while now to make waterfalls etc. and it seems to get rave reviews. I asked an artist friond of mine quickly for her opinion and she said latex has been used for a long time in the theatrical applications IE: masks and specil effects costumes etc. but couldn’t say weather or not how it would hold up over time.