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Hi Folks, about to have my shell blasted and the guy normally uses a red primer (looks like red oxide but isn't) Would I be better asking him to paint the bare metal in etch primer? If so how much will he need? Cheers. Mark

etch primer is porous
if you have it etch primed ensure the car is primed in 2k primer within 24 hours,,or you may get corrosion/microblister issues later on in the cars life,,

if he is using red primer make sure its acrylic or cellulose based
many blasters use synthetic or polyeurathane primers-do not go there!!!!!

if any is left on the shell ,even in nooks and crannies it will wreak havoc with automotive paint finishes once applied!

ask questions and do some homework with the person doing the blasting

hope this helps

the ammount of primer used depends on how much they put on and what fluid tip/needle/aircap or even gun set up the painter is using

Well that's interesting. I always thought that etch primers were porous too. The guy who alarmed me runs a very successful bodyshop and has done for 40 years. I was a bit puzzled, alarmed and now confused.
I will investigate what type of 'red' primer the blaster uses but in fairness it hasn't caused any problems in the past.
Thansk for yoru input. Mark

most good 2k primers are based on powdered glass beads in acrylic resin and pretty corrosion resistant for a good time,,,
etch primers offer corrosion resistance when overcoated only

- black-catophoretic primers are corrosion proof till the coating is broken