I've completed a concrete river and lake and have applied two coats of DryLock waterproofing paint per the manufacturer's instructions. On the river I mixed up a mixture of 50:50 yellow carpenter's glue and water with some colored Drylock mixed in for pigment. This was "painted" on with a brush and clean sand was "drizzled" on to stick in the mixture. The excess sand was vacuumed out and ruddy brown primer, leather brown, black, and grey spray paint were then applied. More sand and some of the paint were then brushed out with a stiff brush and a light dusting of additional spray paint added leaving the various colors as well as sand color and texture for a most convincing effect. As the river runs fairly low and the bottom will be fairly well covered with pebbles, I'm not really too concerned about the bottom sand washing out. I would like to do the same treatment to the lake. However, the glue/sand/paint mixture would be under water a good deal of the time. The lake will remain dry except when running trains or displaying the pike. However, I'm concerned that the glue will not hold up over time as some of the time it will be submerged perhaps for days on end. This would then release the sand which I really don't need passing through the pump and maybe even take some of the Drylock paint off with it leaving a "porus" concrete surface. (I'm not too concerned about the small bit of sand that would be carried into the lake from the river, nor am I worried about the porosity of the river as it is only used for relatively short periods and I would not expect to loose that much water.) The Carpenter's glue instructions say, "Not recommended for use below the waterline." Has anyone tried using the yellow glue below the waterline for extended periods and what were the results? I've tried to get the sand to stick directly to the drylock but the paint lacks the tackiness and dries too fast to hold the amount of sand which gives the desired effect.
Thanks
Todd

Well, I noticed yesterday that the water in small areas in the river where the sprinkler water puddles had a yellow/green cast to it. I can only assume that this is dissolved glue as algae would not form in one day. (This was after only one day sitting in the water.) Today I did do the lake but used mostly a Drylock/water mixture (water was added to prolong the drying time and give me a chance to sprinkle the sand) with only a small portion of the glue. I figured that the glue would supply some additional adhesion for the sand above the water line. Once the glue dissolves below the water line, so be it. When the Drylock paint is totally dry, I will apply spray paint to get the desired shading.
Todd

Todd,
If the Drylok material you used is also labeled UGL on the can, it's about the best material you could have chosen to waterproof your streambed and lake. It comes either in a latex base or some sort of oil base and is a totally waterproofing agent, including water under some pressure. I used it to waterproof my fish pond with great success. Five years with over 2000 gallons and not a leak! Another good product which is sometimes hard to find is a Quikrete product called Quik-Wall. It's a cementous based material that is troweled on and is also totally waterproof. There are specs for using this to waterproof concrete block structures in order to store potable water in them. It has a fibrous material to it also and is used for coating dry stacked blocks to tie them together. ¼" on each side of a block wall will hold up a house according to the US building code. Check them out.

Yes, I used the UGL. But what of th eyellow glue? WIll it dissolve over time?

Yellow Carpenters glue will in time completely dissolve under water. Faster if the water is moving. Is your all your water going to be completely drained from your system? Every time you are not running trains? Or will the dissolved glue reappear to gum up and burn out your pumps when the last of the water evaporates? It all depends how much glue you used, how fast the water is moving over the glue to dissolve it and wash it down stream to your pumps. And how much water is drained or overflows somewhere taking the dissolved glue with it. If there is not too much dissolved glue and your pumps always remain wet, It may not damage them at all. There are many types of yellow glues out there. Why don't you do a test in a pan of water? The best thing that you have got going for you is mixing the paint with the glue you may not have any problems at all, or such a minor amount of glue will dissolve it doesn't matter. You said 50% water and 50% glue, how much paint did you mix into that?
Good luck, and let us know how it turns out.
Richie

Perhaps the mixture is about 2-5% paint. (Like I said, it was only to add dome pigment and avoid the yellow look of the glue.) At this time I have not yet done the lake, only the river which makes up less than about 20% of the total wet surface area.

I don't think you will have any problems. Your lucky you added that paint. It's the best I know of. I don't use anything else to waterproof. I'd love to see your railroad someday.
Richie

Stop by anytime you are in town. In the mean time pre-river/lake pictures are available at:

http://members.tripod.com/~gwschreyer/nov_98/todds_pics.html

and:

http://members.tripod.com/~gwschreyer/opening_day/todds_pics.html

Todd