After pulling the old motor out of my '71, I decided to clean up the engine compartment and spray some black epoxy primer for rust protection. I have a small (conventional) detail gun.

The local NAPA sold me a quart of primer, a pint of activator, a gallon (smallest size they had) of solvent for cleaning before spraying, and a cartridge mask.

I've NEVER sprayed before. After cleaning and degreasing the areas to be sprayed, I assume they should be scuffed. Scotch Brite pad ok for this, or should I use 120 grit paper?

For cleaning the gun after spraying, is the pre-spray cleaning solvent OK, or is there something else I should use?

Any other tips for a first timer?
(Please be gentle.)

Thanks,
mark.
'71 Fodor

Mark, the 120 is too coarse and will show up through the primer. If you want a really nice finish I would do scuff it with a gray scuff pad.

Clean the gun with lacquer thinner. NAPA has an "Econobody" line and a gallon is only about eight bucks, part number 15240.

Remember to clean it GOOD, there is lots of grease and oil stuck in the nooks and crannies of an engine compartment.

------------------
1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

Thanx for the reply. I got the lacquer thinner yesterday.

Decided to do the hood, too, since I had to pull it off to get the motor out. The underside has some surface rust, and the paint is just about GONE on the top side.

What's the best way to protect the metal between sanding and priming? This work is being done in my driveway, as I get time... Between work, kids, and weather, if I wait for a block of time big enough to do it all at once, it will never get done. If I sand one weekend, and paint the next, is there any good protection in between, or should I just plan on a quick re-sand just before priming to get rid of any new rust flashing?

Many thanks,
mark.
'71 Fodor

Well, I did it.
Shot for the first time tonite. The weather and the wife were good to me, and gave me the time I needed.

Don't think I even pissed off the neighbors, at least not yet.

How long will the unused primer and activator keep (Separately)? Any special tips to keep them fresh? Shelf in the garage OK, or should I stick 'em in the frig?

I'm sure I didn't have the gun adjusted quite right; I'll have to review the Basics of Basics. But for just dinking on the frame, cross member, and underside of the hood, I think I did OK... for a first timer.

The lacquer thinner did a great job of cleanup... Can I use it for a pre-spray metal prep, instead of the EZ Kleen? At $7.50 a gallon instead of $25, I could use the savings. Also noticed when spraying thinner through the gun, that it was real easy to see the spray pattern. Should make my adjustment easier next time.

Wow, what a rush. You pros must get a great deal of satisfaction from seeing your finished products... I'll be thrilled if my black primer turns out, well, black!

Thanks for all the help and info, here and at autobodystore!

Cheers,
mark.
'71 Fodor

Mark, seal the can well and that is about all you can do. The hardener is the only thing that can go bad realisticaly, it has about eight months as a sure thing. After that, who knows. The lacquer thinner is too fast for precleaning, the proper cleaner is worth the money believe me.

------------------
1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

The frame rails, firewall, and underside of the hood came out looking so nice, I decided to do the top of the hood last nite before reinstalling. That part did NOT go as well as the earlier work...

First, I was rushed; it was getting close to dark. Also, it was breezy. I noticed that the top of the hood has a lot more "junk" in it than the bottom did, probably because of the wind. But the more concerning part was ...

I had a run near the back of the hood, so decided to fix that tonite. The DA sander zipped right through the primer, MUCH faster than when I was removing the oxidized layer from the old paint. Then I noticed two big scratches in the middle of the hood from moving it -- the button on my jeans? Sanded those out, too; wiped with the EZ Kleen, then sprayed those areas. It's early yet, but it doesn't look like the color is going to be uniform. Maybe it's just "hazy" as it's drying? Also, a little water (long story -- suffice it to say I have a three year old son and a garden hose) got on the wet primer, leaving white spots.

I'm pretty much resigned to scuffing and reshooting the whole hood after it's installed, but I'm wondering
a) why the primer scratched so easily
b) why it came off so easily with the DA

Isn't epoxy primer supposed to get hard? Is it too soon, and just not fully cured yet? How long should it take? Or is there another problem? (MS5121 mixed 2:1 with 5123).

Thanks,
mark.
'71 Fodor
"Soon to be... 383"

Looked at in the morning light, the resprayed areas are definitely lighter (greyer) than the previous coat.

Thoughts on color and hardness?

Thanks,
mark.
'71 Fodor
"Soon to be... 383"

Just a few things to think about. What reducer are you using if any, cant remember if MS expoy has a reducer but make sure its for the right temp rating. alSO expoy has a bad habit of very slow drying, especially PPG. How long did you wait before you sanded? How many coats are you applying? Expoy in my experience always needs to be allowed more cure time then whats listed on the tech sheets. Ive had to wait two days before once with some PPG dplf expoy.

Also make sure you are reading the mixing cup right, Ive read it wrong several times and mixed it wrong...eric

------------------
1970 chevelle
1970 chevelle SS455 not a typo its a buick baby
1949 and 1972 chevy trucks
http://briefcase.yahoo.com/bc/sevt_chevelles

Out of ignorance, I used the word "reducer" at NAPA when I orderd the primer, and they shook their heads. "Nope, you want activator. 5123". And they showed me the mixing instructions, 2:1. Even sold me one quart primer, one pint activator so I wouldn't get it backwards...

Sanding was about 24 hours after the first spray. Maybe too soon? Should I have done it by hand rather than using the DA?

And the mixing ratio is a possibility. I used the wife's measuring cup, and could have misread it (I don't cook much anymore.)

Other thoughts?

Thanks again for all the help. You guys make this site great.
mark.
'71 Fodor
"Soon to be... 383"

hd, some expoys can be reduced down for use as a sealer like DPLF, didnt remember if MS required a reducer also along with the activator. Go down to your paint store any paint store and buy some paint mixing cups. I get mine from PPG and they run about 15 cents each, for 15 you cant afford to mix this stuff wrong.

As for too soon maybe what has the temp been down in your area while you spray? Like I said before expoy tends to need more dry time. Like martin said go with a gray or even a red scuff pad, not as harsh as your da is going to be but be enough for the right adhesion of the next topcoat...eric

------------------
1970 chevelle
1970 chevelle SS455 not a typo its a buick baby
1949 and 1972 chevy trucks
http://briefcase.yahoo.com/bc/sevt_chevelles

Thanx for all the help. I'll look for some paint mixing cups, and pick up some scuff pads.

Cheers,
mark.
'71 Fodor
"Soon to be... 383"