What is PINK board made of and what can I use to seal it so I can pour in some water effects.

Thanks BOB

If you are talking about extruded styrofoam, it's simply polystyrene. I believe the difference between the pink and blue board is the density of the foam, which is graded based on it's insulating qualities. The type of "water effects" you can use depends on their chemical make up. If you are using a chemical resin which generates heat, you may have some problems unless you seal the foam board with a barrier between the polystyrene and the resin. I generally use plaster cast material to seal the foam board, but I've also used clear caulking compound for small areas. Since some resins use acetone or other chemical solvents which are not compatible with polystyrene, rather than take chances of it leaking through cracks in the plaster, I avoid these resins when working with extruded foam board. I prefer to use Envirotex two part epoxy resin, as it doesn't generate much heat, and the extruded foam is dense enough the epoxy won't seep through the surface. I simply sculpt the foam board, paint or use terrain effects, then pour in the Envirotex. Envirotex is available at Michaels, Hobby-lobby and most craft stores
VR, Russ

The difference is in the chemistry...styrofoam is polystyrene...blue is polyurethane...

I think!?

They react differently to glues, paints and products. 99 percent of the time you can cover both with a white glue, water mix and should be able to do anything to it after that....

Maybe!?

I have always just covered with paint.All sides including the bottom to prevent warping.
Never had a problem for sealing.

Tom

Nope-- it's all extruded polystyrene. Owens Corning makes the pink stuff. The blue version sometimes has an outer vinyl film depending on manufacturer, this gives it additional rigidity for construction/insulation purposes, but it needs to be removed before gluing. The only differences between the pink and blue is how it's manufactured using different polystyrene formulations. Liquid Nails is probably the best glue for permanent joins. White glues or yellow wood glues with high tack can also work, but joining is an issue as these glues tend to dry thinner and therefore have a tendency to separate without "grabbing" the foam. I used to be a pretty serious model railroader, and built several layouts from extruded foam board, both blue and pink varieties, including water features. It's best cut with a hot wire cutter, and a foam rasp can be used to shape it. It differs from "expanded" polystyrene (styrofoam) in that it's much denser.
VR, Russ

The fumes are toxic if you use a foam cutter . I like using this foam material instead of the white ..that gets all over the place.lol Seal it with diluted white glue. Use 2 part epoxy to join pieces.
Nice base material.

Bob here is the product information:

http://www.owenscorning.com/NetworkShare/EIS/43522-FOAMULAR-250-XPS-Insulation-Product-Data-Sheet.pdf

I've been using a Micro-mark wire foam cutter for about twenty years now without any problems, it just doesn't give off enough fumes to cause problems, and I'm not cutting it every hour of every day. Not saying you shouldn't take precautions though-- not anymore than a reasonable person would with enamel or lacquer paints or household chemicals of any kind. The white board is not the same thing-- it's "expanded" not "extruded" polystyrene, and is much less dense, which causes it to be lighter and more porous with more air in the foam-- that's why it's more messy. As I said before, I use a foam rasp which is especially made for carving extruded foam board-- you can shape wave troughs, ditches river banks and rock faces with ease, but it to will generate lots of foam "crumbs". I keep a shop vac handy when carving. Joining is easy with Liquid Nails-- I really recommend it-- it comes in a tube or a caulking cylinder (I recommend the tube for smaller joins), is the consistency of caulk, and will join the foam permanently without any mess. It can be spread with a spatula, and has enough drying time that parts can be positioned, without the mess of other glues. Most model railroad scenery applications recommend Liquid Nails.
VR, Russ

Thanks for all the info. I built a scene with a oasis. Everything looked good for a couple of months and then I notices the pond getting smaller and 2 bubbles came up. I sealed the pink board with white glue and water and all seemed ok. I think I will just do another and seal it real good. Thanks again BOB