Coating for metal stilling basin lining.

[FishScreener]

I'm working with a Design Consultant, to solve a problem with a low head dam in a wilderness area.

He is proposing to reline a stilling basin, at the diversion to a micro-hydro power plant with welded mild steel. (Long ugly story of multiple, un-engineered band-aid fixes over the last hundred years compounding into failure of a concrete lining with piping through the dam. And, it being easier to fly enough steel into the wilderness, to make the basin, than fly in enough concrete.)

He is proposing to coat all the steel, with some type of epoxy or an asphaltic coating.

The stream is the natal habitat for two species of anadromous fish, which are on the endangered species list.

I think a better solution would be to leave all the steel bare, and install several magnesium anode bags with test stations so they can be monitored.

Any advice would be greatly appreciated.

 

[unclesyd]

Here are two approaches to your problem, Sauereisen and Perma-Liner.
The Epoxy Products site has a lot of information about Epoxies and Coal Tar Epoxies, but is rather disjointed. I have used products from all sources mentioned and have had very good results.

http://www.sauereisen.com/corrosion/linings.aspx

http://www.perma-liner.com/index.html

http://www.epoxyproducts.com/a_epoxypaint.html

 

[MartinSr00]

I work for a very large wWater agency. For stilling basins where the velocities are very high, we line with 316SS. Tie the plates into the concrete with drop-in epoxy anchors suitable for wet locations.

If you want to coat steel, we use various coatings. Coal tar epoxy is one. The other is high solids epoxy. It chalks in the sun over time, but it doesn't seem to fundamentally damage the coating -- it just looks faded.

We use Amerlok 2 and Skotchkote 306. Make sure you have a 3-5 mil blast profile on the steel prior to coating. Use multiple coats to a total thickness of 26 mils +/- 4. Don't coat too thick, or you'll trap solvents under the paint surface and it won't cure. We have years and years experience with such coatings and our coatings lab tests coatings for a year and a half or so prior to their approval for use. These coatings are pretty good.