OK so I gotta ask the dumb question. I read early on ' bead blast everything ' really ? Pictures are of the hood hinges that I have cleaned, used paint remover on, wire brushed and went over with steel wool. The original greyish phosphate finish covers most of the parts with some discolored staining on some areas. For the most part rust and grease are gone. Is bare metal the desired surface prior to the new P & O application ? Thanks, Brian
Plating doesn't happen very well if at all even over light grease or rust. More likely then not you will get inconsistent results if you don't bead blast prior to zinc phosphating. With fresh bead blasting prior to cooking you are lessening the chance of splotchy plating . FYI in case you didn't figure it out wear rubber gloves (i use the med exam gloves ) while handling the parts so oil from your skin doesn't contaminate the part.
Wire brushing does not get into the moving areas on hinges and latches. Bead blasting does, at least it does a better job. Grease still needs to be removed and it's better to do that before blasting. Soaking is a solvent of your choice (no smoking and fasten your seat belts if you do) is the best way.
Bob stated the grease and consistency problems. That's the real goal - consistency. As to grease, if you don't remove all of it prior to blasting you might spread it around with the beads and air making the items surface worse. For handling, I use a dry shop towel from the blast cabinet to the "to be phosphated area" - it's a quick move and then it's back to blasting. Rubber gloves are best when actually putting item into and taking them out of the phosphate bath. Careful - if you're doing this correctly, the phosphate bath is 180 to 210F.
Each time I get ready I walk thru the process - blast; stage (is it dry); blackening (for bolts); phosphating SST pan; Stove; propane for stove; tools, hooks, strainers all SST; rinse water (I use a 15 gallon galvanized wash tub); drying hooks (bent coathangers); towels for bolts and things that don't "hook"; oiling area (I use the top from a 30 gallon plastic trash can with several sheets of newspaper and a couple of shop towels); WD-40; watch (some parts need to be light, some need to be dark); beer (I know I left out something, so I'll do it again).
A tip on bead blasting - start on the inside edges like on a hood latch, and work your way out. Concentrate on hard to see spots, holes and edges first, the flat areas will take care of themselves.
Jim
