why did i get bumps in my paint
 

this is my 4th car iv painted so admittedly I'm no pro but i think i do ok and more importantly I'm having fun:nod:. anyway the other three cars i did came out very smooth before wet sanding and looked primo. this one looks good but..... between my 2nd and 3rd coat i wet sanded and when i put on my 3rd coat it came out bumpy. not orange peel bumpy but like dirt in it bumpy. iv looked and its not dirt, only thing i can possibly think of is i put the 3rd coat on during a rainy day. i used an hvlp gun with an air dryer. not a big deal i just have a little more work ahead of me for wet sanding but i thought it would be interesting to know why it happened.

thanks

Re: why did i get bumps in my paint
 

anyone? bueller.... bueller.... bueller :)

Re: why did i get bumps in my paint
 

I think it would help a lot if you could post some close up shots of your paint, showing the bumps clearly.

Re: why did i get bumps in my paint
 

ya i can get some pics tonight when i get home.

Re: why did i get bumps in my paint
 

"Bumpy" could mean anything. Why are you wet sanding between coats? Are you using BC/CC?

Re: why did i get bumps in my paint
 

well i just wanted it to be as smooth as possible. so i wet sanded between coats. the paint is bc i think. like stated above i'm self taught and just having fun so no one call me stupid i never claimed to be a pro... well you can call me stupid i guess but I'd still like to know why so i can avoid it in the future :)

Re: why did i get bumps in my paint
 

Nobody's going to call you stupid. Painting can be difficult, kudos for having fun with it. In order for us to help we need some specifics. What brand of paint is it? What type is it(bc/cc, single stage, etc)? Is it metallic? How many coats so far? I'm guessing it's bc if you're sanding between coats. Give us the details and we'll try to help.

Re: why did i get bumps in my paint
 

the paint was "kostumz" i used kirker on the other cars i'v painted and i liked it much better. this paint was more expensive but it was soooo watery, i had a hard time keeping it from running. i'll look when i get home if it was b/c or c/c and take some pics of the bumps.

Re: why did i get bumps in my paint
 

Never heard of either. Google doesn't return anything on "kostumz".

Re: why did i get bumps in my paint
 

bought it off ebay. and kirker you can get through tools usa if i remember right. also the paint summit puts there label on is kirker.

Re: why did i get bumps in my paint
 

Always buy good paint. Cheap paint will not be as good and take more to cover.

bc/cc is base coat(color) then you put the cc(clear coat) on over it.
single stage is just color and no clear coat over it.

I think sanding between coats is way more work then needed, but that paint job looks pretty fancy.

Re: why did i get bumps in my paint
 

well the kirker i used on the other three cars came out really really nice. even had some pros tell me they didn't beleive i painted it cuz it looked professional. and kirker is pretty cheap. this kustomz paint was more expensive and it was just like water and they still sent a bottle of reducer with it. i wwaatteerr i had such a hard time not getting runs. i had to spray very light or it would start to drip. the orange car by my name was kirker paint and that one looked primo. i don't just kinda bummed me out seeing all these little bumps in it.

Re: why did i get bumps in my paint
 

Pics? Are the bumps a different color, like dirt? Are they completely clear? Info.

Re: why did i get bumps in my paint
 

i was hoping to have some pics for the thread but i had a busy night. i know kinda pointless to start a thread without the pics. they are the same color as the paint(green) they sure feel like dirt and about the same size but i cant see it being that as they are evenly throughout the paint job. and i was very carefull about airflow through the garage when i painted. and i washed the car down before i painted with some cleaner from the paint store as well.

Re: why did i get bumps in my paint
 

Sounds like solvent pop. Check this out and tell me if this is what you see.

Re: why did i get bumps in my paint
 

hmm ya pretty close. maybe not as much as are in that pic but looks like the same little bumps that i got. intersting, and like stated in those pics, this paint was extremely then paint. i did'nt even need to use reducer.

Re: why did i get bumps in my paint
 

Roll it outside and let the sun bake it for a week or so, block it with 400,(320 if using a single stage) go buy some good paint, and shoot it again. Use your local shop. There are lots of paint lines that are inexpensive for you to play with. Oh, and if your doing graffics, use base/clear. It costs more, but it's worth it in the end.

Re: why did i get bumps in my paint
 

I had the same problem when I was painting a set of wheels. The inside and outside were painted differently, so were masked. The area around the edge of the "spokes" would have bumps, exactly like you described. But only in those areas. I was using rattle cans. Thru trial and error, I found that the paint was drying before it actually hit the surface. It's called dry spraying. I believe two things caused this. First, I was spraying outside in the bright sun. Second, I would hit the middle of the rim first, and move up. This caused the overspray to dry and fall to that area of the wheel.

I'm guessing that you were shooting a little farther back than your other cars, so that the paint wouldn't run. Try getting closer to the surface, and ease up on the kicker, if that's the type of system you're using.

Re: why did i get bumps in my paint
 

OP BE CAREFUL if you do what haps suggested since you use cheap paint if you put good paint on top of it the chemicals will react and your paint will begin to wrinkle so if your gonna shoot again spray your first 2 coats dry and then go to medium wet DO NOT spray it wet you WILL have problems

/even if its completely baked if you spray wet coats or medium wet on ur first pass chemicals will react

Re: why did i get bumps in my paint
 

Unless he used a latex for his base coat, which I doubt he did, he'll be fine. Cheap paint or not, it's probably a catalyzed urethane. He only needs to worry about lifting if he puts a lacquer over the urethane.

Re: why did i get bumps in my paint
 

trust me i've seen it dozens of times with solvent base paints, ask me how i know lol if you haven't seen it happen is probably because either u haven't sprayed over cheap paint and clear or you always spray your first coats dry... i've been painting for a living for years so I KNOW what the paint does by personal experiences,anyways i don't wanna start an argument im just warning OP of what could happen

Re: why did i get bumps in my paint
 

Yes, I've seen it. Yes, I've done it. The list of things that COULD happen goes way beyond this. A couple thin coats of primer over it would solve that problem. If anything will lift it, the primer will. If it doesn't, then he's good. Probably wouldn't hurt if the previous paint solvent-popped.

Re: why did i get bumps in my paint
 

I had the same problem and I thought I had some chemical reaction but I figured out that when I sanded out each layer I got it too smooth and the paint wanted to bubble up instead of sticking. Someone said above about using 400 grit paper, this will take care of the problem because it leaves enough texture so the new layer will attach. If you use anything finer then 400 grit you will run into the problems you have. Nice job by the way. Mark

Re: why did i get bumps in my paint
 

yup he should use a sealer to be on the safe side if its gonna be re sprayed