Hydrocal vs Drywall Mud...

[mbshaw]

I saw the other thread about hydrocal and it got me thinking... would drywall mud be a good alternative? I mean it's ready to go, easily formable, sands down well, accepts paint, and is readily available. Other than the dust, it seems it could be a good alternative.

There are a couple of things about drywall, it's heavy and can shrink if applied to heavy/thick.

[Anonymous]

Hello mbshaw,

If you're building hardshell scenery, use hydrocal. Drywall mud doesn't have any where near the strength hydrocal does. I've taped and mudded sheetrock, and the pre-mixed mud is too thick to dip a paper towel into. Thinning it with water would only weaken the mud further. The scenery base will be more susceptible to damage, and may even collapse.

If you're looking for something to layer over carved extruded foam board scenery to add texture, drywall mud would be an acceptable alternative. However, I prefer Sculptamold for this step or even plaster of Paris. Both are tougher than drywall mud and are lightweight, too.

Regards,

Paul Schmidt
Contributing Editor
Trains.com

[Anonymous]

There is an alternative product that I still use quite successfully, as hardshell paper-dip, as a hardshell cover coat, and over styrofoam as well..it's a commercial slow-drying Polyfilla. It comes in large sacks and you add it to water, as with all Polyfilla, to the consistency you want. The slow drying feature suits me really well, for shaping or carving without having to rush.Paul is right on about the drywall mud..not suitable .
regards /Mike

[Anonymous]

Hi Mike,

I've heard Polyfilla is lightweight, like Sculptamold, and just as strong. I'm wondering if it's less expensive, and if we can get it here in the states. Or maybe it is Sculptamold under a different brand name.

One of the layouts featured in Great Models Railroads 2003 is an OO British Rys. layout and has scenery made of Polyfilla. It's an exhibition layout, which piqued my interest about Polyfilla.

Regards,

Paul

[douginut]

In a Google search I found Polyfilla at
ENGINEERED WOOD PRODUCTS
160 Hanes Avenue,
North Vancouver
British Columbia,
Canada V7P 2L8
Tel: [phone]
Fax: [phone]

good luck it ain't supposed to be in North America. but it is.

Doug

[rogerhensley]

For mountains and hills, in a word, no. For coating surface scenery, yes it will work. Hydrocal and Ultracal 30 are forms of concrete. Using the hard shell technique properly, it has enough strength that you can almost get up and walk on it. The oldest part of my railroad has been moved twice, lifted off of the table/support and moved with NO DAMAGE. It was first put down in 1982. Can't do that with mud.

Now, there is another product that I use for scenery coating because it has strengh and that is Durham's Rock Hard Water Putty. Readily available and inexpensive. It also has the advantage of not being white, but an off yellowi***an color. When you chip the scenery, you don't have a white spot, It is more nearly an earth tone.

Roger
NMRA Beginner Pages
http://www.nmra.org/beginner/

[Anonymous]

Sometimes a liability can be an asset. The cracking with drywall compound is a reality, but some have used the cracks to model areas that have cracks, quite successfully.

[Anonymous]

Hi Paul....Polyfilla is not Sculptamold. It is essentially a patching and repair plaster, with a degree of elasticity. Lepage, a former Canadian entity, is now owned by a huge multinational consumer product corp.....Henkel.
The www.henkel.com website is typically large and unfriendly, as is the www.lepage.ca site. I have emailed them both, [actually no answer from last week's email to Lepaage yet, so I tried again].
best regards / Mike

[Anonymous]

About Durham's: You can mix it up pretty thin so that it doesn't cover or fill up any fine carving you've done to extruded foam, etc. This leaves you with a very thin (but "Rock Hard"!) shell over the foam. Also, you can add a little paint (water-based) to the mix so that it becomes your base color. Doesn't seem to affect it setting up at all.

[BNSFNUT]

I use a lot of rock castings on my layout and used dry wall mud to fasten them to my hard shell base (Woodlands Plaster and plaster cloth}. I use it to blend in castings, it will some times crack but with rocks it looks ok. You must wet the base plaster first to get a good joint. I have used dry wall mud to coat some areas that need the surface touched up, you have to keep the layer very thin.