Air Conditioning - Raising Stack for AC coils, base can rusted

Hi,

Here is my old setup and old base can:

http://www.skylab.org/~chugga/forums/IMG_6448_1.JPG

http://www.skylab.org/%7Echugga/forums/IMG_6514_1.JPG

http://www.skylab.org/%7Echugga/forums/IMG_6517_1.JPG

My bottom base can is gone, but there is a pile of dirt and a bunch of rust spots where it was touching the concrete

http://www.skylab.org/%7Echugga/forums/IMG_6660_1.JPG


Should I backfill it with concrete to create a more sealed off and supported area?

What makes a good vapor barrier for the ductwork?

definitely a layer of concrete on the bottom, spray the outside of the metal with cold galvanizing compound, then before installing the new metal, line the cavity with a plastic moisture barrier type material. That sure is a tight place to work in.

definitely a layer of concrete on the bottom, spray the outside of the metal with cold galvanizing compound, then before installing the new metal, line the cavity with a plastic moisture barrier type material. That sure is a tight place to work in.


Would you just use a 6-mil plastic? I also have a roll of peal-n-seal (the same kind of stuff they use to seal roofs) I'm not sure about it getting hot though if it would out-gas.. I've also heard that some kind of 1/8 rubber would be good for it to sit on.. Plastic might spring some leaks if it is metal on concrete. Where might I get some 1/8 thick rubber pad?

you know I've been thinking about this and maybe painting the concrete all the way around with some masonary waterproofing would be better than plastic. I'm not sure but maybe the home center stores might have some thin foam cell insulation. You might also spray in some expanding foam then trim it. There used to be a product available called no drip, we would paint it inside metal drain pans, I don't know if it's still made.

Nu-Calgon: Products: Aerosol Products (http://www.nucalgon.com/products/products_aerosol.htm)

scroll down and look at pan spray