Is this paint and primer OK for painting stompboxes?

[Ponchus]

Hey all
I want to paint some of my boxes, so I picked up some Krylon paint. I got the black Interior-Exterior paint, and black Interior-Exterior primer. I also got a Krylon clear laquer spray, but I can't remember the exact one. I think it was just called Laquer. Anyone know if these are ok? I'll be painting standard aluminum boxes, as well as 1 or 2 RACO boxes.
Thanks

[markm]

I strongly reccommend a primer that is self-etching as that's about all that will really stick well to aluminum.
Hard to find but worth it.
Try smallbear, Steve has it from Eastwood.
Good stuff! 

[Ponchus]

Sorry, but what does "self-etching" mean? And if a primer were self-etching, I assume that it would specifically say so on the can, right? I don't think mine did...

Is there anything I can do to maximize my success rate with my regular ol' primer? I'd really hate to have wasted the money on it, plus having to shell out more money for shipping and whatnot. Plus I'd love to start painting tonight or tomorrow...

[John Lyons]

Self etching means that the paint will eat slightly into the aluminum enough for the primer to stick. It's usually a light green color and will say self etching in the name. It's not mandatory at all but it will help. Most auto parts stores will have it. Kragen/Napa/Autozone etc etc.

If you don't want to spend $5 more on the self etching primer then just sand the box with 120 or so grit sand paper and then clean with alcohol, naphtha, laquer thinner, acetone or mineral spirits and let it dry. Then paint away. Should be fine.

John

[Ponchus]

When you say "then paint away", do you mean that if I sand with 120 grit, I won't need primer? Or by "paint", did you mean that I can use regular non-etching primer after sanding?

[96ecss]

I agree with Mark about the self etching primer. I've never used regular primer on a stompbox but I have a friend who is a metal fabricator and works with aluminum alot. He said even when regular primer does stick to aluminum, it doesn't last very long. See if you can return the primer you bought and get the self etching.

As for "then paint away" I'm sure he meant you still have to prime.

I hope this helps.

Dave

[jimbob]

I just bought the Eastwood black self etching primer. Kinda $$$ but works great- Plus shipping is also $$$. I think anyways, but I also ordered direct from Eastwood. I think this is a must have as I notice chips of pain ect.. on those without it.

[John Lyons]

It's not the end of the world if you don't prime with self etching primer but you will be better off doing so. I've painted a lot of boxes with just regular primer and they are ok. Enamel is going to chip either way. Maybe less with self etching primer...

I meant "paint away" with the regular primer...

john

[markm]

It's not the end of the world if you don't prime with self etching primer but you will be better off doing so. I've painted a lot of boxes with just regular primer and they are ok. Enamel is going to chip either way. Maybe less with self etching primer...

I meant "paint away" with the regular primer...

john

I've painted loads of enclosures with regular primer with success too.
I agree with John that the self etching primer is not a neccessity however, lots of guys that complain about paint chipping and such will notice a major difference with the "correct" surface preperation and the use of the self etching primer.
Even "cheap" paint will stick better when the enclosure is primed with the self-etching stuff.
Cold Galvinizing, Zinc Chromate etc are great for steel, Aluminum is an entirely different ball of wax.

[mojokicks37]

Hey,
I've been using the same brand and the interior-exterior version, and I have no complaints thus far.

I sanded my aluminum enclosures with 220, then 600 wet/dry dry. Then I brushed all the loose dust/particles off with a dry paper towel.
From there, I sprayed a solid coat of the primer on, let it dry, and then applied a couple of coats of the other paint on top, sanding lightly in between as neccesary.

Then I clear coated and all is well so far.

Hope everyone's doing well!

[Gilles C]

What I do for aluminum is I clean with acetone and prime with gesso. This is what I use.

http://www.krylon.com/main/product_template.cfm?levelid=5&sub_levelid=8&productid=1823&content=product_details

I started to do that when I learned how to use an airbrush with acrylic paint. It worked very well for me.

Gilles

[Ponchus]

Thanks for all the great info thus far everyone!

I do have one new question. My first painting project will actually be a RACO electrical junction box. I believe that those are not aluminum. I think they're steel, but I'm not sure.

Will I need to do anything different to paint this box than I would for aluminum? I'm hoping to use the same primer,  paint and clear coat for all.

[enigmur]

Sorry to revive an oldish thread.

I am just up to painting. I got regular non etch primer, and it seemed to stick okay.
But I made the mistake on buying really cheap paint for the top coat. I did a thin coat and the paint goes all powdery and grainy looking  Painting isnt my thing.

Anyway, so I'll go and get some etch primer and another type of paint today if time allows - what should I look at getting? Does it matter what the ingredients are as long as they are compatible with eachother?

Thanks

[Brian Marshall]

if you are going to finish the box with krylon, dont bother with self etching primer... krylon is going to chip a bit over time anyways.

[m-theory]

If it's galvanized (spackled looking steel, like a garbage can), you need to use an acid wash.  Well, if you were leaving it outside, anyway.  Truth be told, for what we use these things for, just about anything will work.  It's all going to chip some down the line anyway.  The time to get all anal about substrates is when you're painting something that's going to be subjected to extremes, like rain, sun, snow, cold, etc. 

The reason that your thin coat of paint got "powdery" looking is because you were probably a bit too far away from the target, and the solvent evaporated on the way there.  The solvent used in aerosols is generally very fast.  You want the first coat to be light, but all coats should be sprayed about 6"-10" from the surface.  After the first coat sits for just a few minutes, you can lay a medium coat on top of it.  Let that dry for about 10 minutes, and lay another medium coat, and you should be good.  Don't "pound" the coats, or you'll cause either runs or solvent pops.  Just be patient.  This isn't a process you can rush.  If you wait more than an hour, you'll have to wait 7-10 days before hitting it again, because you'll cause lifting otherwise. 

For primer, you are better off using a self etch primer (I get mine at NAPA), but in reality, a TRUE self etch primer is a two part product, with one part being acid.  That stuff is amazing.  Sandblasting won't remove it.  The aerosol is really good, but it's not the same.  I use an acid etch on my boxes, then follow that with a good cleaning, a good coat of self etch primer, then some build primer, and after sanding, a sealer.  Probably overkill.  Like I said, they'll chip somewhere, at some point anyway. 

[enigmur]

Thanks a heap for that, it was very informative.

I got some different paint + primer, so hopefully all should go well.

Just another Q for you M-theory. How long do you let primer sit, and how many coats?

[m-theory]

How long do you let primer sit, and how many coats?

Dry time depends upon a lot of variables...base resin in the primer, ventilation, temperature, and of course, mil thickness. 

Duplicolor "fill primer" dries rather quickly.  Rustoleum takes forever. 

How many coats, and how much material to apply depends on what you're filling, assuming you're talking about a build primer of some sort.  If you finish sand with 320g, and there aren't any weird pits or other defects, a couple of medium coats should be fine. 

Apply coats after the previous coat has "flashed off," meaning that it doesn't appear wet anymore.  Probably about 10 minutes or so, with medium coats.  Don't wait an hour between coats, or if you do, you'll have to wait probably several days to re-coat (check label), in order to avoid lifting.

Btw, self etch primer doesn't need much mil thickness (2 mils).  It's purpose is adhesion, not fill. 

Just take your time, enjoy yourself, do the best you can, and it'll be fine.  It might help if you were to find a metal substrate that you could practice on, until you get a feel for spraying.  It's not hard, but it does require a bit of practice. 

[enigmur]

Thanks for the info!

It is looking really nice, I had to sand it down in a few spots to get rid of specks of dust, but it has another coat on thismorning.

This should be my last coat, and I will wait for it to totally dry (12-24 hrs) before applying the clear gloss coat. Should I sand the surface lightly (I have 400 grit paper) before applying the last coat? It seems to have stuck fine on my bottom plate of the box - I used the bottom of the box as testing grounds 

Cheers! By the way, there are a couple of pics in my Axis Face Debug thread.