advice needed BEFORE the water is poured

[new2nscale]

HELP !! Here is my dilemma.... I have pink 2 inch foamboard down over a hardcoated plastic table. I cut out a "U" shape pattern of the foam where I want a lake/inlet to be. Over the plastic I placed a plywood 1/4 inch piece of wood for the lake floor, so the water would be poured over the painted wood. But, and here is the problem.......I had to trim some of the foam away from the edges of where the plywood floor sits, and there is a 1/4 to 1/2 inch gap between the foam and the edge of the plywood. What can I put or squeeze into these gaps so the water doesnt drain down into the gap ? Also, I dont want a visible gap either. Can I plug or press plaster of paris into the space(s), paint it after drying like I do the plywood, then simply pour the Woodland Scenics Realistic Water over it ?? Or what else could I use instead of plaster of paris ?? Some gap-filling spray foam ??? What material would "take" to acyrilic paint the best, beore being covered by the W/S H20 ???
thanks to anyone in advanx thats "been there/done it"

 

[BMK]

I had a major problem with my pond which turned out to be an ingredient in the spackling compound I used to fill in gaps. I contacted Woodland Scenics and they suggested covering the pond area with plaster cloth and then covering it with “Woodland Scenics Flex Paste” before pouring the “Woodland Scenics Realistic Water”.

 

[NH Mike]

For a gap that big I'd carve some pieces of foam to sit on the plywood and butt up against the sides of the foam you had to cut away. Cut them at an angle to simulate a sloped embankment. They don't have to fit perfect. Just close enough for a much smaller gap. Common latex caulking from the paint or hardware store can be smeared into and over the gaps to seal them and can also be used as the glue to put them in place. The caulk will take latex paint that you use for the depth color before you pour the WS water liquid. Most solvent base paints will eat away at the foam board so use latex.

 

[Jon NFL]

new2 - I've found that ANY hole in the base will allow your poured "water" to drain. After getting a nice smooth coating on my floor I started sealing the pond bed before pouring the "filling" mix. I also discovered that MAGIC WATER (and the cheaper versions from the big box stores) will wick far above where I want the water line to be at the shore.

I started practicing with road side ditches and wet spots in the road and smaller ponds. After getting the pond bottom set with rocks, debris, tree snags, tires etc and natural colors I layer in the MW. Bottom layers have some color - blue, green, aqua - what is best for the particular body of water. My main pond is about 2.5" deep with 10-12 layers poured. (this pond has a turtle swimming away from a sunken tree , a snake coming ashore, and a small fishing dock - I had a lot of extra time that week )

I bought a package of 8oz plastic cups and mixed small batches to pour. In the attached pix you can see some of the wicking problems. Install scenery down to water's edge.

 

[GrampysTrains]

Hi new2: I would use plaster cloth to cover the bottom and extend it up on to the shore. Then, use pink spackling over that. Glue stones, sticks, etc., let it dry, then paint. Then pour water, I used Magic Water. DJ.