humiditypaint
I have a wall that often gets wet. It's a very thin wall and I think it's water that somehow just infiltrates. This happens mostly in the rainy season.
I am not looking for the ultimate permanent solution. For now I am just looking for a cheap solution, that may keep things looking a bit better.
Would painting with plastic paint help to keep water out
In the end, I ended up using DRYLOK® LATEX CONCRETE FLOOR PAINT
It's holding up well so far, we'll see how it does over the next few years.
Perhaps you should consider using a chemical help to supplement your heat gun approach. Obviously the very old paint has lost most of the oils and resins that can help it bubble for heat removal. You are probably dealing with mostly pigments (many metal based, including lead) and very dry resins.
There are newer less caustic strippers, such as citrus based products, that take several hours to cut through the old paint and may need a subsequent application. But they may allow more complete removal without gouging the old wood.
Once you stop making satisfactory progress with the heat gun, let the wood cool than then test the stripper in a small area. NOTE - Do not, under any circumstances, use the heat gun when there is a chemical stripper on the wood. Serious chemical reaction or fire could result!
You also could try cabinet scrapers. these are much less likely to gouge than the heavy duty paint scrapers. Some have sharp corners or curves that allow you to scrape out moldings and insets. Again, these could be used once you have removed a good bit of the old paint with the heat gun.
NOTE 2 - Given the age of the paint, there is almost certainly lead (and maybe other unpleasant metals) present in the finish. Use a mask to avoid breathing the dust and chips with all these techniques.
Best Answer
Trapping the water in the wall is no solution, it will only wreck the wall more quickly.
Any paint you put on there will fall off the wall, as it will be pushed off by the water. I use a lot of different paints from LPU to powdercoat. Nothing I know of will do what you want.