Parkerizing prep

[DLBlack]

I am going to Parkerize before I spray with Gun Kote. I am hearing some say sand blast first and some say bead blasting is fine. What is the opinion of those here who have done this? Thanks.

[Colt45guy]

I've never had good luck with bead blasting. It peens the surface of the metal and doesn't give any sharp protrusions for the park to adhere to.

Sand blast is the only way I've ever gotten factory-like results.

[sevenL4]

Sand consists of rounded pebbles. Less uniform than glass beads but still round. Look up blasting abrasives online. There are several that will do a better job with finer grit (gets into tighter spots) that won't change the shape of the gun.

[Dave Berryhill]

Sand is not a good media to use in any blasting cabinet because it contains free silica and breathing the dust is not healthy (commercial sand blasters wear a positive airflow breathing mask).

Parkerizing doesn't "adhere" to the steel. It's a conversion coating, which means that it reacts with the surface of the steel. However, blasting with a sharp media such as aluminum oxide does seem to work better as surface prep for parkerizing than glass beads or polishing because it's cutting action gives a rougher surface, which results in more surface area for the phosphate solution to react with.

[David Rose]

If you happen to live near a distributor, Dupont Starblast XL (sand) contains "less than 1% silica". Since I don't know how much silica is in "normal" sand, that is relative. But it is legal in CA, which says something I suppose. That is one of the recommended abrasives for Gun-Kote if not using the Parking first. If you aren't close, shipping eats up the savings.

David

Sand is not a good media to use in any blasting cabinet because it contains free silica and breathing the dust is not healthy (commercial sand blasters wear a positive airflow breathing mask).

Parkerizing doesn't "adhere" to the steel. It's a conversion coating, which means that it reacts with the surface of the steel. However, blasting with a sharp media such as aluminum oxide does seem to work better as surface prep for parkerizing than glass beads or polishing because it's cutting action gives a rougher surface, which results in more surface area for the phosphate solution to react with.