Before I built my main creekbed with a seamless continuous piece of Woodland Scenics’ Shaper Sheet, I did a short tributary with the usual Masonite base and strips of plaster gauze for bottom and banks. When it came time to pour, though I thought I’d been careful enough, it soon dripped out the bottom and onto the pessimistically placed old towel on the floor beneath; it’s impossible for me to pinpoint where the leak is.
Now that it’s all dry, I’ll try to patch it from underneath with straight Hydrocal. But friends are suggesting that as it dried, the hole may have been plugged by itself. I’m tempted to pour in some real water as a test, but I’ll just ask: what are the odds, do you think? Should I just go ahead with a second pour of Magic Water? Rip it all out and start again? Try shining a bright light through to check?
Any advice, or tales of woe, or other comments, will be most welcome.
Did it seem to come from one spot? If more than one spot, a major rebuild may be needed.
Was there anything left once it quit draining? If not, then the hole was in the lowest spot. If there was a puddle left, then the leak is not in the low spot.
Patching from below with hydrocal seems tricky.
If the riverbed is done with water soluble techniques, adding water could make a mess of it. If not, then try a little water, but I’m leery of it myself.
I suspect at least one, and probably several little breaks or holes where the banks meet the hardboard. I would smear a light film of clear silicone caulk around the banks where they meet the base, let it cure, and then try again.
Can you post a photo? Not really necessary, but I like seeing things. Is the scenery and everything all done and you’re just adding “water” as the final step? I can’t really help since I haven’t done this yet, but I’ve been researching in preparation for when I’m ready for my river. Depending on your situation, a couple of layers of paint might be enough to keep the “water” in.
I’ve used Magic Water a lot and had a similar problem. I added small amounts of Magic Water as a test and in both cases the hole had sealed itself as it cured. Both times the leaks were very small.
I’m going to run down these very helpful suggestions, including the photo idea–I’ve been putting off learning how to do that. I’ll try to remember to check back in with results. Thanks.
I mentioned to my neighbor that I was about to seal things from underneath with silicone caulk before pouring a second time, and he told me about a spray-on sealant advertised on TV for fixing small roof issues; Flex Seal is the one I wound up with, but there are others. He picked up a can at the local building supply place and even crawled under the layout and sprayed it on for me. In 24 hours I made a pour, and in another 24 I had a nice creek. The pour revealed how much more careful I should have been with slope and other engineering factors, but when it comes to adding water next time, I’ll do better.