Questions on primer

I have some metal parts that have been sandblasted to the bare metal. I don't want to paint them yet. I might not want to paint some of them for a few years. Does primer stand up to weather? Can I wait a few years and then just lightly sand the primer and then paint it? Suggestions?

 

use epoxy primerHouse of Kolor KP2CF is green and sandable.A lot of epoxies arent sandable.i blasted my 62 galaxie parts and didnt paint them until 5 yrs later paint still looks good,!

 

I used PPG dp90 epoxy primer to store some of my parts,

 

Regular primers are not sealers,,so the metal can rust under the primer.

DP90 would be a good bet! HRP

 

If I use one of the recommended primers can I then use body filler, putty, a high build primer, etc. over it years later?

 

Hey,

I'd step up to a full urethane resin based primer. DP 90 LF no longer contains heavy metals like lead ,cad & zinc It's not the product of days gone by


" Do not reach greedily for the Kool-Aid "

 

What is the advantage of having urethane in a primer?

 

I put two coats of the PPG dp90 stored parts. When I went back to the parts I just scuffed them applied my high build primer or fillers and finished as normal. It's been done three years now and have no signs of any problem.

 

Urethane resins are a little newer technology, and interlock alittle tighter than epoxy resins. Too, since you'll probably be top coating with a urethane, all of the chemmies are of a LKQ nature

I wouldn't suggest you top coat over the old primer without a reprime & sealer prior to goin to a final finish!


" Humpty Dumpty was pushed "

 

So is a product like Dupont Vari-Prime (self etching primer) now completely obsolete?

 

No. just different application.
I like the HOK stuff, like Mike does. BUT, depending on environment, even a good water resistant primer might not hold up. Dampness, sunlight, etc. all work to break down primer, and eventually rust will form under it. If it's in a heated garage, it will last for years. Unheated, depending on the severity of the weather, it should still last a year or more. Lots of hot/cold cycles, or dampness/condensation will shorten it's water shedding qualities.
Outside, in the blazing sun, or lots of rain, I'd want to strip off some areas to check to see if there is rust underneath before continuing to paint, it is longer than 6 months. Just to be safe.

 

"No. just different application."

I spoke with several paint people who feel self etching primers are obsolete technology.

"I'd step up to a full urethane resin based primer."

Seems like epoxy primer is what most are using over bare metal.

 

alot of 2k urethane primers have a etching agent in them and also are corrosion resistant i am fond of ppg ncp 271. but if you just want to protect it from corrosion for a period of time and are going to do any filler work on the part than go with an epoxy primer. bodywork over properly prepared epoxy primer is good, body work over etching or urethane primer no good.

 

I have had good luck on fresh sand blasted metal with epoxy. You will have a good foundation for future work. Would not recomend outside storage, but if not advoidable put an extra coat or two. Look up your products tech sheet, especialy on epoxies because some have an induction period (time after mixing before spraying for chemicals to react). I had to strip some parts once bedause of this.