Sealing a river bed for Envirotex

[MisterBeasley]

I have a small pond and stream which I'm going to fill with Envirotex.  Right now, I've gouged out some pink foam to form the bed, and I've put down plaster cloth on it.  I'm not too worried about most of the small holes in the plaster cloth, because it generally lies right on top of the foam anyway.  However, there's one spot by a stone wall where there might be a gap.

Does anyone have any suggestions for sealing up plaster cloth so that I can pour Envirotex on it without worrying too much about leak-through?  I do plan to put some plastic down on the floor beneath the layout anyway, just in case, but still I'd like to contain the Envirotex to the the stream bed.  Thanks.

[Phoebe Vet]

What I do, is I shape my water feature then cover it with plastic wrap if it's a river or a plastic grocery bag if it's a small pond, then I put my plaster cloth over the top of that.

[selector]

Mix up a tiny batch of plaster, or hydrocal, or squeeze in some latex caulking....you can use anything that won't shrink excessively and that will suffice as a plug until the epoxy hardens.  In my own case, I used a powdered wood putty that required the addition of water to mix it into a putty-like consistency, and then I spread it all around to create a vessel.  That was my first layout.  For the second, current layout, I just used Plaster of Paris and created a wide, shallow well, damming the open edges of that module with painter's tape.  I spread newspaper in several layers below the module and then did two or three pours to get the depth I wanted over the dirt and sand and gravel glued to the "river bed" so that it looked reasonably natural.

[CascadeBob]

Isn't Envirotex a solvent-based product?  If it is, shouldn't there be some concern about it coming in contact with underlying extruded foam which it might dissolve?  I would think that the safer approach would be to put a good coat of plaster in the bottom of the water feature and paint it to give the bottom colors.  This should seal the bottom so the Envirotex will not contact the foam underneath.  It probably would still be a good idea to put a sheet of plastic under the layout in case there is any leakage.

Bob

[MisterBeasley]

I've already tested Envirotex in carved-out depression in a scrap piece of foam.  There was no problem at all, so I'm not worried about that.

[saronaterry]

Envirotex Lite won't eat foam. It's all I use. First I gouge out the river or whatever and then coat it with a soupy mix of drywall mud. Latex paint works well to seal it. Then paint the lake/stream bed and pour the water.Like Selector, I use tape to make a dam at the edge ofthe layout.

Terry

[Ibeamlicker]

I used a thin layer of plaster of paris,painted it black in the middle and greenish/blue near the edges(cheap latex paint)just pour the envirotex in thin layers it tends to creep up the sides.also W/S brown ballast looks good for sand.Good luck. 

[modelmaker51]

Isn't Envirotex a solvent-based product?  If it is, shouldn't there be some concern about it coming in contact with underlying extruded foam which it might dissolve?  I would think that the safer approach would be to put a good coat of plaster in the bottom of the water feature and paint it to give the bottom colors.  This should seal the bottom so the Envirotex will not contact the foam underneath.  It probably would still be a good idea to put a sheet of plastic under the layout in case there is any leakage.

Bob

Envirotex is an epoxy resin and will not attack any plastics, including styrofoam.

[HarryHotspur]

Latex paint worked fine for me.

[HHPATH56]

    As IBEAMLICKER stated,"It seems to creep up the sides".  When using Magic Water, I had the same problem. Is there anything one can do to prevent this capillary action "creep" ?

[gandydancer19]

    As IBEAMLICKER stated,"It seems to creep up the sides".  When using Magic Water, I had the same problem. Is there anything one can do to prevent this capillary action "creep" ?

Not that I know of. 

However, you can correct it by painting the "creep area" with clear flat paint.  Model Flex has some in a small bottle you can brush on.  You can then add some more of the same type ground cover if you wish.  After all, scenery is a model too, and sometimes you have to work on it in several steps to get it to look right.