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I started on the mountain area of the layout tonight and was wondering, I have some DAP patching plaster in a container that I wont be using for anything else. Has anyone ever used this as an overcoat on plaster cloth. Are there positives, negatives, or should I just stick to hydrocal (which is more expensive anyway)
I did just that. I cut a bunch of layers out of foam and put the plaster cloth over that. But noticed it looked like steps almost so to smooth it out, I used patching plaster over top. Looks great, solid etc. Just don't go too thick with it...it'll crack. Start with 1/4 inch layers or less.
Aaron: this may be too late, but most patching plaster and drywall joint compounds are not very strong and as said, will also crack easily. If I were going to use it, I would put a couple of layers of plaster gauze on for added strength. Also, I buy plaster gauze from a medical supply house. It cost half of the price of WS at around $4/roll (bought by case) and is a bit larger than a Woodland Scenics roll.
I just did a large area using plaster gauze with plaster cap. I started using Plaster of Paris, but while it is cheap the set time is very fast and you don't have much time to work it out, so I went back to Hydrocal. If you have a large area to do, you can order 40 lb. buckets ($25) online or sometimes find it locally. Online you have a huge shipping charge of $25, but it is still way cheaper than the hobby cartons, per pound.
Sorry I missed the beginning of this! What I've done is put the plaster cloth down, and with a wet finger smooth it until all the little holes are filled...which they never do fill completely!
What I do then is while it's still wet, sprinkle some lightweight hydro-cal on it and it fills the holes and dries to a fairly hard shell. If there's any hydro-cal still powdered (not mixed in) I just mist it lightly with water.
Ta-da!
OCN: That's a good idea to get the weak spots that we always have with one layer. I still believe that a plaster cap is needed, particularly if we talk about large hills. I have fractured several areas in weak spots just by adding trees and other scenery. I also like to "gob" areas for handcarving rock faces .
I've just basically used two layers of plaster cloth, with the hydro-cal sprinkling on each layer... It creates a pretty hard shell. Mind you, I've only done this on dioramas, and my new layout is not yet at this phase! Tensile strength over large areas is yet one more thing we have to be concerned with. I'll post results later when I'm at that phase, but just thought I'd share what's worked for me...
Heck, that's an excellent idea and I will use it in the future.
I have a lot of large areas that I have covered in hills/mountains and cost becomes a big issue; that is why I only use one layer of plaster gauze. An added benefit with the plaster cap is to round off/fill-in areas that still have the frame's shape. I use cardboard lattice framing and you can understand how many dimples and knots exist after the gauze. The plaster fills these in and also gives me the opportunity to add more shape and contour to specific areas by just using my fingers. Messy...but it works fine!