my first coat-another surface prep q?

[nuttyman]

I was going to first de-grease, then glass bead the surface. My question is what should I clean the part with after the glass bead? I'll be doing aluminum & steel parts. If I do not use an iron phosphate wash for steel or a zinc chromate for aluminum could I use something like denatured alcohol to wipe the parts down & dry with compressed air?

nutty

[non-stick]

You just answered your own question,bud. Denatured or MEK is the way to go. Anything left after blasting will just be light surface oils from handling and blasting smut. I suggest getting a container and a paint brush, setting one end in the container and "brushing" the solvent on starting at the top and working all the way down until you have sufficiently "rinsed" the part and hit all surfaces. After that.... blow off with compressed air and that is more than enough clean to powder coat over. Keep it simple and quick, ya know? Hope that helps.... Russ

[nuttyman]

it does, thank you. One other question about outgassing AL. When outgassing prior to coating @ a set temp, should I then coat while the piece is still hot or should I cool the piece then coat?

[non-stick]

depends on surface area and how bad the cast is, basically. A good rule of thumb to follow is while the part is still warm, but not too hot to where the powder will begin to melt. Say..... 200-300 degree range or in that area. If you pre-bake at 375 range, by the time you remove it from the oven and set it up to coat, it *should* reach that temp. If in doubt.... let it rest for 30 seconds and then coat. Otherwise I don't see any real trauma in your future with it.... Russ

[tomg552001]

I'd recommend definatlly using a prep wash like iron phosphate or zinc chromate, to me it seems like pretreatments make a world of difference. I also find that blowing the part off right before you coat can be effective, especially if you work in a dusty area. Surface contaminents can really screw up your finish. Good luck

[nuttyman]

great-thanks for the help.


nutty