On 2006-12-14, Thomas Prufer wrote:

Oh no, the tin lasts a long time. And I think any old solvent would do to thin
the stuff if it had dried up a bit. Let it get good and warm give it a good
stir, and off you go.

I meant that the bitumen paints I've used all have weathered off fairly quickly.
There's a few that supposedly last a lot longer: some sort of water-soluble
acrylic roof paint, or two-pack epoxy stuff. One look at the label: coverage
rates and the price tag mean that I can either put up a new roof for the money,
or keep the money and slap paint on every two years or so.

Thanks for the info. I'll look into the butyl pond liner, or else
"reinforce" the bitumen paint with sand.