Paint gun spray problem...

Rich

Rich

Asshole at large
Joined
Mar 17, 2005
Location
Central PA
When I spray mineral spirits, it sprays a nice pattern, and very evenly, consistantly, and smoothly.

But when I spray the rustoleum primer, cut approx 15-20% with acetone, it sprays the pattern fine, but it's not consistant.. it's like a water pik.. comes out in pulses...

The instructions for the primer call for up to 15% dilution with acetone, but damn that stuff is THICK coming out of the can, I can't imagine it spraying well with less dilution...

Should I dilute it a little MORE, maybe to 25%? The stuff goes quickly, too.. I've used 3/4 of a quart just doing the cowl for the cruiser... should it take 2 quarts of primer just for the hood, cowl, bib (holds the headlights), and fender skirts? at that rate, you'd certainly use a gallon of the stuff for a Jeep-sized vehicle...

The gun is a siphon-feed, running at 55psi... originally was up to 80, but it was just vaporizing the paint, and not as much was in the spray... it seems to feed slightly better at the lower pressure, as well.

P.S. If anyone's been keeping tabs, I've "solved" the oil in the output of the compressor air by running 2 disposable driers inline just before the paint gun.. :rolleyes:
 
experiment with diluting it more and try a little bit higher pressure. also make sure that there is no impurities whatsoever in that primer. take the time to run thinner through the gun between coats to clean the nozzle. also after a few coats you might want to take the nozzle apart and clean all of the seperate parts to be 100% sure its clean...running acetone through it dosent always do a good job.
 
A few things to check also would be moisture in the air line. They sell little inline filters that do wonders. Also I had a similar problem when spraying some primer. It ended up being bad primer. It had sat on the shelf too long....like 3 years.
 
Metto said:
experiment with diluting it more and try a little bit higher pressure.
Click to expand...

higher pressure? hmm, seemed to work better at 55-60 vs. the 80 I started at...

I might be wrong, but it doesn't seem like a clog problem... the spray pattern is perfect, it's just not drawing the primer consistantly.. But it draws the mineral spirits perfectly..

I was planning on screwing around with more dilution tonight, on the other panels, but I have to get paint on the cowl tonight so it'll be dry by morning, and it can be mounted back in place so I can finish fabrication.
 
I had the same problem last weekend. mine was due to i tried to use primer i had left over from last summer. like you said it was thick right out of the can. is it fresh primer is my first question. and what was the mixture? is the second. my primer called for a 4:1 ratio mix. if it is old primer as i used i would recomend getting new primer. and second if it is fresh primer and it is that thick i would make sure it is shaken real well and i would try more reducer. just my .02


Dudley
 
crash said:
I had the same problem last weekend. mine was due to i tried to use primer i had left over from last summer. like you said it was thick right out of the can. is it fresh primer is my first question. and what was the mixture? is the second. my primer called for a 4:1 ratio mix. if it is old primer as i used i would recomend getting new primer. and second if it is fresh primer and it is that thick i would make sure it is shaken real well and i would try more reducer. just my .02


Dudley
Click to expand...

DING DING
 
I know you said it isn't clogged but you could try soaking the gun in paint thinner if thinning the primer doesn't work. I'm assuming you have a regular sprayer. I normally run one filter and havent had a problem with my gun. Could try a lower pressure like Bruiser said. I would normally spray thinner through it after each use and the soak it if necessary. If it's not the paint and not clogged adjust possibly?
 
I bought the paint the other day, and it's from the new Lowe's, and had no dust on it, I'd bet it's pretty fresh.

What will happen if i dilute it more? Does it just go on thinner, that's the only side effect?

To answer the mixture question, this is rustoleum primer.. the ONLY mixture is "up to 15% with acetone" per the directions.

Also, remember - the gun pulls a thin fluid perfectly...zero problems
 
Wait. Is this automotive primer? Or metal primer from Lowes? I know nada about how to spray anything other than automotive.
 
plain metal primer from lowe's. :D
 
Hmmm, reviewing what you've said, thinner mineral spirits sprayed ok, but primer doesn't. Me thinks I would try thinning the primer more and spraying extra coats.
 
Rich said:
plain metal primer from lowe's. :D
Click to expand...

Damn, I though I was a cheapskate :flipoff2: . Honestly, I can offer anything on that. Is it sprayable in a gravity gun or does it require a siphon/tube to work? Well if all else fails, thin to spray, spray to thickness in coats. That always works.
 
Franklin said:
Damn, I though I was a cheapskate :flipoff2: . Honestly, I can offer anything on that. Is it sprayable in a gravity gun or does it require a siphon/tube to work? Well if all else fails, thin to spray, spray to thickness in coats. That always works.
Click to expand...

Not sure, it just mentions "being sprayed", but I'm using a siphon gun. With no adverse effects from thinning more, "hi ho, hi ho, it's off to Lowe's I go.." for acetone... :D
 
I'd try to thin it a little. You may use more additive but I think the paint is probably a little to thick. You will just have to spray more coats on. I don't have any experience with that type of primer though? Is it sandable? I always use regular primer the what ever paint then but Truefinish a urethane clear coat. None of those are as thick.
 
Sorry Rich, wasn't on the computer much this weekend...thin it out more! It will be more RUNNY (ie watch for runs) so put it on with thinner coats...and more coats. Remember my mistake was wanting to cover it too quickly.

And..paint wise, I had some red left over from the 1 quart...so I shot 70% of BUG with 1 quart or so. (I will double check that with dad when he swings by here in a minute)

Sam
 
I thinned it out about 35%, worked pretty good... I did use damn near a quart on just the cowl, but what the heck...

Thanks for all your help guys!

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