If you blasted with fresh sand and handled the part with clean gloves, you can apply RustSeal directly and skip RustBlast. The blasting already gave you the anchor profile. Plastic media, bead and soda blasting are the exception: those methods do not leave enough profile for RustSeal to bite into, so those surfaces still need RustBlast even though they look clean.
When You Can Go Straight to RustSeal
Skip KBS Klean and RustBlast only when all of these are true:
- The metal was blasted with fresh sand, not recycled media.
- It has been handled only with clean, gloved hands.
- Loose blasting dust has been blown off.
- It has not sat around since blasting.
A clean, freshly sandblasted surface is the ideal substrate for RustSeal, and adding RustBlast to it introduces water, which makes the surface more prone to flash rust. That is the one real argument against doing RustBlast on a sandblasted part.
When RustBlast Is Still Required
Plastic media, bead blasting and soda blasting do not provide adequate abrasion for a direct RustSeal application. Those surfaces need RustBlast for further etching. This is the point the old FAQ page did not make, and it is the one that costs people adhesion.
Also run the full three step system if the part has been touched with bare hands or has sat for more than a few hours in a humid or dirty shop. The blasting profile is still there; the contamination that landed on it since is what costs you the bond.
If You Do Use RustBlast on a Blasted Surface
You can apply RustBlast to a sandblasted surface before RustSeal. Be aware that the surface will be more prone to flash rust if it is not dried immediately after rinsing. Apply RustBlast full strength to a dry surface, keep it wet for the documented dwell time, rinse thoroughly, then dry right away. See how to minimize flash rust for the specifics.
Always Wear Gloves Handling Blasted Metal
One bare handed touch transfers skin oils, and slight residues of grease, oil or fingerprints can ruin an otherwise good paint job. Gloves are not optional on a part you intend to coat directly.
Frequently Asked Questions: RustBlast After Sandblasting
Still have questions about blasted surfaces and RustBlast? Contact us for help.
