Quote:
Originally Posted by CostelloCrew
what is the advantage of the self etching primer?
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You'll need to etch galvanized or otherwise zinc coated steel products. Otherwise the paint won't stick. You can either use an acid to etch (such as Ospho), then prime and paint as usual, or you can use a self-etching primer then paint. Self-etching primer removes a step in the process, though I don't think it's as effective as the full 3-part process. I've been having good luck with it on the satin-coated steel, but for properly galvanized steel I use the 3-part process.
Etching is still a good idea on normal, new sheet metal as well. Helps the paint to bite in.
Quote:
Originally Posted by CostelloCrew
also, originally i was dead set on using 2" foam board in my walls for insulation. then i found a pourable expanding foam option that i am leaning towards now. my question is why does nobody use the old school fiberglass batts or rolls? is water the issue or is it the better closed envelope that expanding foam gives you?
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Have you pulled your interior walls yet? Most people will find fibreglass insulation back there.. usually covered in black mold. It seems that fibreglass is simply a poor choice for being sandwiched between metal since humidity condenses on metal and fibreglass acts as a sponge. Rigid foam insulation (when gaps are taped or filled with spray foam) and spray foam are nearly vapour barriers, have higher R-values and aren't as absorbent as fibreglass.