Trouble spraying clear..?
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Ok, heres the deal, we are novice at best, but we have a Devilbiss entry level gun, and we have painted some small things with no trouble, and now we put white stripes on a hood. Everything laid fine, got the stripes on, and when we cleared the whole hood, we couldnt help but get tiger stripes of rough clear as we went, it didnt seem to matter how much overlap we had, it would just move the stripes. What went wrong? Too much pressure? Not enough? We ended up unloading clear on it heavy so it leveled out on its own, but it wasnt the right way to do it. Any idea?
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Dry spray in clear is usually a result of too much pressure at the gun or the gun being held too far away from the surface and the clear literally starts drying before it hits the panel. Also, what was the temp of both the air and the surface when you were shooting the clear?
Bryan
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There's a few variables that can attribute to that.
1. Type of clear being sprayed. By this I mean the clear itself, the speed of the hardener and reducer used with it. They have to match the temperature of the booth.
2. The size of the nozzle in the gun, and the setup of the gun. By this I mean the "fan" of the gun and the ""fluid" of the gun. The fluid is the screw on the back that stops your trigger and limits the amount of fluid coming from the needle. Having this too far in can cause a dry spray.
3. The compressor volume. Can the compressor keep up with the airflow of the gun?
4. Painter. Picture the needle of the gun as a pancil or pen, and keep it perpendicular to the surface you're painting. Keep a moderate overplap... like 40-50 % of your last pass and you should get no dry spray.... if all the other conditions are right.
1. Type of clear being sprayed. By this I mean the clear itself, the speed of the hardener and reducer used with it. They have to match the temperature of the booth.
2. The size of the nozzle in the gun, and the setup of the gun. By this I mean the "fan" of the gun and the ""fluid" of the gun. The fluid is the screw on the back that stops your trigger and limits the amount of fluid coming from the needle. Having this too far in can cause a dry spray.
3. The compressor volume. Can the compressor keep up with the airflow of the gun?
4. Painter. Picture the needle of the gun as a pancil or pen, and keep it perpendicular to the surface you're painting. Keep a moderate overplap... like 40-50 % of your last pass and you should get no dry spray.... if all the other conditions are right.
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You might also have some trash in the nozzle causing it to spray uneven. Practice on paper and see if the spray pattern is even from top to bottom, some guns if the fan is not adjusted right it will spray heavier on the top or bottom. Almost like spraying with half the fan pattern.
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Judging by all the variables...I think I'll blame it on our measuring out the clear not quite right, and probably the pressure set to high. I think we had the gun maxed out as far as flow as well. Each time we couldnt get the pattern we thought we needed we either raised the psi or opened up the flow...probably screwing ourselves at each juncture. The air comp. was a 60gal Craftsman..so Im sure thats sufficient. I'll try to get back to the basics with the next spray.