paint problem....dust coming out of the paint gun?

When I pull the trigger on the paint gun, along with the paint, it shoots out some crap that looks like little strands of dust. (or at least, it looks like dust to me)…

It’s not just “every now and then” either…It’s a steady stream of dust strands, or fibers, or whatever they are. You can hold the paint gun up in the air and spray it, and clearly see all the strands of dust coming out.

Anyone know what could be causing this?

If there’s already a thread about this somewhere, please post the link.
I searched and couldn’t find anything…

all I’ve found on the hamb regarding dust and paint, is talking about cleaning the surface before you paint….

 

What material are you spraying? Make sure you are mixing the materials correctly, clean the gun check your air pressure and make sure there isnt crap in your air lines maybe this will help?

 

What are you spraying? Tip size? Air pressure? Reduced correctly? Is paint coming out as well?

 

I'd say the material's not reduced enough, and too much air pressure.

 

Hey,

'sounds like improper reduction of material shot at high pressure. In the good old days this was known as "spider webbing", or "Cobwebbing", done with old lacquer type finishes.
Clean gun and reduce the material to proper ratio to finish, shot at correct pressure for gun and material in use.

 

Use a paint strainer, if there is something in the paint it should show up in the strainer. If the strainer is clean, pull the fluid needle out and feel the paint with your fingers, dose it seel grity? The gun might need to be broken down and cleaned. Check your air by spraying just air in to a clean paper towel.

Most likely the paint is too thick and is not adomizing. Just like cobwebing affect.

 

man, thanks for all the replys so quick...

yeh, spider webs is EXACTLY what it looks like when it hits the surface.

The paint I'm using is lacquer. It's Dupli color "paint shop" (cheap $20/quart ready to spray stuff, no mixing)

I did try thinning it though and it didn't seem to do much.
Should I try thinning it more?

It has a 1.4 mm tip. I've got it set at about 40 PSI. The paint IS coming out also, but it just looks like a spider web laying down in it.

I'll try checking the air like you said "death trap man" by spraying just air (with no paint)...

 

forgot...

yep, I used a strainer. When you look down in the paint cup after pouring it in...it looks clean.

 

I think Lacquer requires a thinner for reduction with Lacquer paint thinner .. not Gun Wash thinner.... it is possible the Lacquer is to thick.. so you are getting the webbing.. at first It sounded like you were having paint gun issues.. if your cleaning it out with paper towel.. you will get fibres.. as mentioned make sure you use a Paper strainer, or one that fits inside the gun.. that will help some what.. or just maybe your air preasure is to low.. are you using a suction feed or hvlp gravity feed gun?

 

If it's lacquer, it's definitely needs more thinner.

Back at the resto shop I used to work at, once in a while we'd need speaker grilles and bezels painted with a pebble grain on them to look like vinyl. We would spray lacquer out of the gun with very little reducer, it would spray out like cobwebs, exactly as you describe, and would make a lumpy surface on whatever was being painted. Worked great for that purpose.

So I'm confident that's what you have happening, and that if you thin your lacquer enough you will be able to spray it fine. Nothing wrong with the gun.

 

here's a pic I took...holding my hand back far enough so as not to get much paint, but just enough to catch some of the strands...



it's gotta be the "spider webbing" like your talking about.

I'll try thinning it more... Thanks!

 

What exactly are you using for paint? Acrylic lacquer , Or?? got a picture of the Can of color?

 

I don't think it's acrylic lacquer...doesn't say it anywhere at least...just lacquer...

the color is "jet black"
here's a link to it...
http://store.summitracing.com/partdetail.asp?part=SHW-BSP200&view=1&N=700+401129

 

What % are you reducing it?

 

Sounds like you have too much pressure or its not thinned enough. You may also check to see if the reducer is the right speed ie:slow, medium, fast. If the temp is too warm for the reducer it can also do this.

 

I think the thinner is "medium". When I was thinning it trying to see if it would help...I don't even know how much I ended up trying. I just kept adding more and trying it on test pieces to see if it even made a difference. I figured if it looked like it was helping...then I'd try to figure out how much to add....

Is there any certain % you would recommend for it?

 

also forgot... it's a gravity feed HVLP gun

 

I would start off with 20% mix of lacquer thinner .just try a small amount in a tin can.. . it may have some reduction already.. the preasure , try 30 lbs at the gun. at about 7 inches from the panel.. you will get a 5 to 6 inch pattern.. try it on a test panel first.. lacquer flashes real quick.. try a slow drying thinner..

 

looks like old paint to me

 

cool...

hate to go into another problem, but you say to hold the gun about 7 inches away. that's pretty much what I've always heard and thought was right...

but, when I held it that far, it was getting a ton of orange peel. I had to end up holding the gun probably 3-4" from the piece to get it to spray and kinda "flow" together right. any closer and it would get runs, any farther and it would look real dry and had a ton of orange peel...

do you think that is part of the same problem (the paint being to thick)?

 

might be, I bought it at a local store...every time I go in there, it looks like none is missing, maybe they just keep it stocked pretty good...but more likely, they don't sell much and it's been there a while

I don't know...

I'm gonna try thinning it more like everyone said... I think that's got to be a big part (if not all) of the problem.

 

wrong temp reducer. what temp are you shooting in?

 

Could be Old Paint.. all have a shelf life.. if it was frozen. even quicker. most go seedy first.. and when sprayed it looks like little specks of dirt every where..

 

If you'd like to find out for sure what the consistency of the paint should be for spraying... look at the manufacturer's (gun's) viscosity rating for the type of paint you are trying to spray.

Pick yourself up a viscosity cup from your local paint store ($5). Basically you just time how long the cup takes to drain through a sized hole in the cup and thin as required to get as close to the correct timing for drainage as stated. Add thinner to speed up the timing.

It's a little more work in the beginning... but it's the only way I've ever found to accurately get the paint to spray properly... otherwise... it's just a S.W.A.G. (scientific wild ass guess) as to how much thinner to add.

Just from what I've been taught and my two cents,

Good Luck,
Ted.

 

I don't know...temp was about 90 outside... no air in the shop, but still a little cooler than 90

 

90 degrees, along with the lack of thinner and high pressure, will cause this. When you say you have to get within 4 inches of the panel to avoid orange peel, that's another sign of the same problem. A thinner mix will help the paint flow better. When it's that hot and the paint is that thick, the paint is partially drying before it hits the panel, which is what's giving you the orange peel effect.

Slow-dry thinner would help too.

 

i seem to remember running my hvlp gun at 20 psi for enamel.

 

I just shot a few quarts of that same paint, and it shot great. I just shook the shit out of it, dumped it in the cup and sprayed!
I would say your pressure is too high

 

cool, I was hoping that was part of the same problem... I new that couldn't be right to have to hold the gun that close.

 

do you have a machine that shakes the paint, or do you just do it by hand?

...I shook it up pretty good by hand, but was wondering if a "paint shaker" machine was necessary?