I’m in the process of building a layout. It has a stream, running into a bay area. Being that it’s my first layout of this magnitude, I alreading cut out the foam for the stream and bay, and neglected to leave an edge. IE: I took it right to the end of the layout. I understand that plastic water will find a way out. My stream and bay are carved into 1" foam, over 1/4" ply. I lined them with Plaster cloth and then sealed them with 2 layers of Gloss Medium, then 2 layers of paint, and now I’m topcoating them with gloss medium. But I would still like the depth of artificial water. Can I run a bead of silicon or latex caulking around the bay edge and at the end of the stream. Will that be enought of a seal to keep the water from running on the floor ? Or should I play it safe and just go with multiple layers of gloss medium.
Do the Woodland Scenics plastic pellets make a thicker pour that may not leak ?
Any two part epoxy that purports to dry “clear” is sure to work well, but you must use light multiple pours to get any depth and good finish. Tinting the lower layers with food colouring or clear inks works well in most cases, but check with the manufacturer.
Your first congratulatable step was in recognizing your mistake, but it is by no means a show stopper. The good news is that 1"-2" wide painters tape, the green stuff is what I use, pressed firmly against the edge of the table and the trough to be filled will do a great job. The secret is to have as flat and smooth a table edge as possible so that the tape does not have to be forced into nooks and crannies, possibly tearing.
Remember, mulitple pours to get the depth, tint each one until the last couple maybe, and the first should be dark! Also, while it is curing, cover it with something stable and unbending…i.e., that won’t sag onto the curing surface. This is to keep dust and pets off the surface.
Allow one full day for a cured first pour, and probably two for every pour thereafter.
I used the green painter’s tape backed up on the outside by a foam block screwed to the inner fascia.
Also, If you want to add fish and other underwater/inthewater stuff don’t forget to insert it between layers (before the final pour). I nearly forgot that part.
As for your question, I believe that any kind of quality caulk will work but might show.
I forgot to mention that you can use a wood putty thinly spread wherever you have joints, such as between layers of foam. So, depending on your stream depth, you would be well advised to seal the entire length of the stream bed up to just higher than your intended/expected “water” depth to ensure none of the epoxy seeps through and onto the floor. The dried putty is paintable, and doing so would obviate having to tint the first layer if you were to paint the central portion essentially black, and the outer thirds a lighter tan colour.
If the Woodland Scenics plastic pellets you are asking about are their EZ Water, they have to be melted on a stove. If you get them too hot they turn yellow; too cold and it will set before you can get it smoothed out. It’s very difficult to get it at just the right temperature to satisfy Goldilocks.