Spraypainting valve cover..bubbles getting all over??

[a_scobel]

So I'm in the middle of spray painting my valve cover..the paint's been going on fine & smooth so far, but suddenly no matter what I do, or how close I hold the can from the cover, it keeps putting bubbles out (Normally after putting a coat on it would be smooth & shiny, but there's little bubbles getting all over the cover now). Any ideas?? I'm shaking the can enough, following the directions on it.

 

[1gcrazy]

I say sand all the old paint off and retry it cus maybe the old paint and the new paint isn't compatable....it's happen to me on a r/c car body. Either that or get new paint. Thats my .02

 

[a_scobel]

I say sand all the old paint off and retry it cus maybe the old paint and the new paint isn't compatable....it's happen to me on a r/c car body. Either that or get new paint. Thats my .02

There was no paint on my valve cover to begin with..I'm thinking it might be the can though. I just started using a new can, and I didn't have the problem with any of the other cans...Here's a pic:

 

[wolf20043]

There was no paint on my valve cover to begin with..I'm thinking it might be the can though. I just started using a new can, and I didn't have the problem with any of the other cans...Here's a pic:

Those spots are made from oil and chit yhou might have missed when cleaning the valve cover. You can let it dry, sand it to smooth and respray that spot.
Mike

 

[clipse0001]

I always sandblast any engine part I am about to paint. There is nothing else you can do to that crap. It is better to get it blasted then to waste time and paint man. You can also get it powdercoated. The guy that does my sandblasting also does powdercoating and he said that he would do my valve cover for like 40 bucks.

If you cant get it blasted i would soak it in some hardcore degreaser and then powerwash it. make sure you let it sit in degreaser for awhile. You can also try spryaing it down with some adhesion promoter (make sure its the high temp kind) before you paint it.

What kind of paint are you using. A good idea is to use Duplicolor engine enamel or their ceramic coats (these are only matte though).
Hope this helps. Good luck
Anton

 

[a_scobel]

I always sandblast any engine part I am about to paint. There is nothing else you can do to that crap. It is better to get it blasted then to waste time and paint man. You can also get it powdercoated. The guy that does my sandblasting also does powdercoating and he said that he would do my valve cover for like 40 bucks.

If you cant get it blasted i would soak it in some hardcore degreaser and then powerwash it. make sure you let it sit in degreaser for awhile. You can also try spryaing it down with some adhesion promoter (make sure its the high temp kind) before you paint it.

What kind of paint are you using. A good idea is to use Duplicolor engine enamel or their ceramic coats (these are only matte though).
Hope this helps. Good luck
Anton

I sandblasted it before I started painting it. I'm using the Duplicolor engine enamel..but seriously it didn't start doing this until I started using this new can. Is it possible the can is just messed up?
Here's the stuff I'm using..I'm using the Gloss Black.

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[1993eclipseGS]

That happen to my last valve cover. I let it sit for alittle bit and dry up, Then I hit it with lite lite coats and luckly they filled in and were un-noticable. I had times where that has happen and I hadto scuff them and start all over though.

 

[GloriousDSM]

your not supposed to paint too close, keep the nozzle about 6-7 inches and wait for each coat to dry

 

[selmerguy]

I used the same paint and did a halfassed job of prep and it turned out ok. Sounds like the can was getting empty and shooting airbubles with the paint.

 

[TRBOBLU]

I highly doubt the spots are from the new can. It looks like there is contamination on the valve cover(ie oil or something else) which is causing the paint to "fish eye" or spot like that. It happens to the stuff I paint when its not cleaned properly.

 

[gthompson97]

looks like your trying to undercoat it.

there's 2 ways that could have happened. either you didn't prep the valve cover good enough, or you got a bad paint can. try painting something else (piece of scrap metal, etc) and see if it does that. if it doesn't, then you'll have to sandblast all that paint off of there and start over. just be sure it's PERFECTLY clean and that it has COMPLETELY dried before painting it. when your done it should look something like this, nice and smooth.

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[a_scobel]

your not supposed to paint too close, keep the nozzle about 6-7 inches and wait for each coat to dry

No matter how far away or close I got it still does it..Actually when I'm closer it doesn't do it as much.

I sandblasted it, took a dremel with a wirebrush to it, & sandpapered it..I'm pretty sure I prepped it enough. I think I'm gonna sand those parts down a little, wait a couple days for the paint to cure, then clean it, dry it & put a new coat on. See how it goes then.

 

[clipse0001]

No matter how far away or close I got it still does it..Actually when I'm closer it doesn't do it as much.

I sandblasted it, took a dremel with a wirebrush to it, & sandpapered it..I'm pretty sure I prepped it enough. I think I'm gonna sand those parts down a little, wait a couple days for the paint to cure, then clean it, dry it & put a new coat on. See how it goes then.

Try using a different can or clean the nozzle with some paint thinner or gasoline. It is possible it may be clogged and the paint is catchig air as it comes out of the hole.

Anton

 

[AgntorangeDSM]

well in body shop terms those bubbles you show in the pic look like "fish eye's" from oil and dirt, you could just sand the top layer with a 1000 grit then to a 1500 grit wet sand paper and then dry it an use a degreaser agnt, like Acry-solve and wipe it down good and try it again. that should really help

 

[a_scobel]

Try using a different can or clean the nozzle with some paint thinner or gasoline. It is possible it may be clogged and the paint is catchig air as it comes out of the hole.

Anton

I just put a coat down on this cardboard orange juice box I had laying around..put down a smooth coat, no bubbles.

I'm just gonna sand the bubbles down & try to clean the valve cover really good..if that doesnt work, guess I'll have to start from the very beginning with taking the paint off...I've already spent like $20 on paint though

I'd really hate to start completely over.

 

[Amazin' Wasian]

I just put a coat down on this cardboard orange juice box I had laying around..put down a smooth coat, no bubbles.

I'm just gonna sand the bubbles down & try to clean the valve cover really good..if that doesnt work, guess I'll have to start from the very beginning with taking the paint off...I've already spent like $20 on paint though

Wipe it down really good with wax and grease remover right before you repaint it.

-nick-

 

[redeclipse7782]

I would just sand down those spots then wipe it with rubbing alcohol.

 

[gstowner]

I aggree with everyone else. Just sand it down with some 400 and re-spray. What kind of paint and primer did you use?

 

[Scrymerr]

I just put a coat down on this cardboard orange juice box I had laying around..put down a smooth coat, no bubbles.

I'm just gonna sand the bubbles down & try to clean the valve cover really good..if that doesnt work, guess I'll have to start from the very beginning with taking the paint off...I've already spent like $20 on paint though

I'd really hate to start completely over.

How long between coats did you wait when it bubbled?

 

[a_scobel]

How long between coats did you wait when it bubbled?

Eh about 10 minutes or so, like it said on the can. I've since finished with the black, & laid down the clear coat on it. It doesn't have that smooth-as-black-glass look to it, but it looks fine to me.

 

[1g4g63pwr]

Same here i agree with everybody else in this thread , you should usually wait 20 mins for each layer to dry and yet you do need to spray it 5-7 inchs away from cover. If i was you redo the whole project again.

 

[Jrivas617]

I just did my valve cover as well...and boy was that a biach i wish i woulda powdercoated it...but ne ways i say change that enamel crappy paint and go to home depot and pick up the rust-o-leum enamel paints...those really are great. But dont listen to that guy who posted about the doing the candy apple red because that was ABSOLUTELY CRAP...Thats not how to do a candy apple red paint job.

 

[Scrymerr]

Eh about 10 minutes or so, like it said on the can. I've since finished with the black, & laid down the clear coat on it. It doesn't have that smooth-as-black-glass look to it, but it looks fine to me.

I would do lighter coats, and probably wait longer. You want to give the paint sufficient time for the solvents to evaporate out before burying them again. The bubbles are possibly from solvent popping. This is the result of not allowing the first layer to flash off, and then putting more paint on top. The solvents will try to escape the first layer often causing the top layer to bubble.

 

[sk8shorty01]

i paint cars almost every day and i will tell you a painters worse nightmare is oil and silicone... both will make the paint do crazy things... oil, even as small amount as whats on your fingers, can make the paint fisheye (little pits or dimples) and silicone will make the paint bubble and fisheye everywhere and really bad... silicone is something that is really hard to get off but it will always make a paintjob look like crap... also if you are using a laquer based paint and you already had paint on the engine before that was acrylic (normal spray aresol can) based the laquer will react with the acrylic paint, no matter how long it has been there, and will cause really wierd looking cracking pits fisheyes, pretty much everything you dont want in your paintjob... definately sand it really really well... and what i did the first time was take it out and bought an electric toothbrush and just went crazy with it on the valve cover... after all this i later brought it down and got it bead blasted, and powdercoated... i think it cost me 50$ or so which is not bad...

 

[sk8shorty01]

oh and by the way, dont use any grease or oil based solvents... the best one you can find is called KAR-SOL and they sell that at your local paint and autobody stores get that if you want to do it right... i think its about 8$ for a gallon and there is no grease or oil basing in it... think about it this way.. if oil is bad, why would you smear grease or oil back on it when you already took all that time to sand all the oil off??? that just doesnt make sense so anyone that tells you to use oil based solvents will cause you to have massive fisheyes ... take my word for it get the KAR-SOL it will make your job easy and it will be done right...