My base keeps warping!!!

Good advice from heavyart and Ralph Marshall. I would agree with Ralph Marshall in using a medium density fiberboard or plywood for a base and trim it with your favority molding. Let the molding rise above the base to give you an edge to butt your material to. If you must use wood it will expand and contract regardless of how much finish you apply, the finish just slows down the absorption. Most important with wood is if you use one coat on side A use one coat on side B. In other words treat all surfaces the same. This keeps the mositure absorption even and will lessen the tendency to cup. Your best bet however is MDF or plywood or if you handle it properly, that is don't use glues that will melt it, styrofoam. Styrofoam is commonly used in model railroading as a base for layouts. HTH Joe

QUOTE: Originally posted by Abdiel QUOTE: Originally posted by ddayomaha Why do you drill holes in the base? My guess is that it gives the celluclay a better purchase on the base.

Precisely.

Thanks for the advice Ralph I think I'll try plywood next time.

I agree with Gino, although a full coat of most kinds of paint should do the job as well. I have a garden shed in my back yard that is sheathed with particle board and painted and it does a great job of repelling the water. That said, I also made some oak Adirondack chairs that I sealed with spar varnish and that works quite well also, especially for the horizontal surfaces.

A piece of solid wood is probably not your best choice for this, as it will expand and contract slightly with changes in humidity (I also dabble in furniture making). For the purpose of providing a solid base you could use either MDF or plywood, both of which will stay a stable size (and thus not risk cracking the clay once it all dries) and are more likely to start off flat in the first place. In any case, make sure you paint/varnish all sides of the material, not just the top.

Thats what we're here for

QUOTE: Originally posted by ddayomaha Why do you drill holes in the base?

My guess is that it gives the celluclay a better purchase on the base.

Glad I came across this thread before beginning the ground material application to my Battle for Berlin dio (my first dio, BTW). I really appreciate learning from the mistakes of others

Why do you drill holes in the base?

When using Cellucaly, drill a number of holes abou an eighth of an inch in you base. Mix in white glue, ballast and earth tones acrylic paint, with the Cellucly. The mixture should be the texture of thick oatmeal and be applied no more than 1/2 inch thick. It the mixture feels wet, there's too much water. If it feels damp, there's still too much water. It should feel sticky and clumpy for best results. it will dry faster be less llikely to warp the base.

Thanks guys

Bottom line, seal the wood first.

Guys, all these recommendations are great, but the reason the wood warps is due to too much moisture, then it drying out and warping. The best method is to seal the wood with a quality varnish or urethane to prevent the warping. All the above recommendations will not prevent warping. Less material, thinner celluclay, paint (may if it is a good, thick latex or enamel to seal the wood), and thicker wood will all still cause warping/warp when the moisture from your groundwork gets into it and then dries out.

Or try a thincker base - 1/2", 3/4".

you can also paint it first, that helps too.

My layer of celluclay was less than 1/8 inch thick but thanks for the advice Matt

My only addition to the good advice that's been posted already would be to use as little groundwork material as possible. Whenever I have a base with some contour to the groundwork, I use layers of foam-core board (held together with hot glue) to form the rough hill shapes. When the shape's close enough, I cover everything with a much-thinner layer of Sculptamold, etc. Since it's thinner, it dries a lot faster, and things are less likely to warp.

Hope this helps!

Matthew Usher @ FineScale

Thanks heavyarty, That explains it

The Minwax didn't fully seal it. Minwax is mainly a stain with a very light sealer to give it some shine. You need a really good sealer, I recommend an outdoor varnish or spar urathane to fully seal the wood.