HVLP Gun problem - barely any paint when opening fan control

[branimal]

I have a Husky HVLP gun that I've used for 4 small projects.

I've noticed on the last 2 jobs barely any paint comes out when I open the fan control beyond a small circle.

I'm spraying Ben Moore Satin Impervo (oil alkyd paint). It sprays fine when I have the dial set all the way in - small circles. Once I open it up barely any paint comes out. And I've opened the paint control to wide open. I've tried thinning the paint down - still having the same problem.

I'm running 30-32 PSI at the gun. I have a Hulk 2HP 20 gallon compressor running a 100' 3/8 hose.

Tip size is 1.8.

I've taken apart the fan control knob and cleaned it as well as the paint control knob and the gun air pressure knob. The paint cup's air hole is clean.

Not sure what's jamming the gun. What else can I disassemble and clean? The manual makes mention of a needle packing nut. I'm not sure how to get access to that.

The first time I used this gun (oil paint 2018), I think it sprayed ok. Then a couple months later I sprayed clear coat and it sprayed ok. I cleaned the gun off with lacquer thinner. And then put it away for 2 years.

Any ideas?

 

[sberry]

I am hvlp guy but thin the paint some more and see if it goes thru.

 

[demarpaint]

If gun is clean, the first thing to check is if the tip is the proper tip for the material being sprayed. Next up is if the paint is thin enough to be sprayed.

 

[branimal]

I am hvlp guy but thin the paint some more and see if it goes thru.

I tried that. I thinned it with quite a bit of mineral spirits. It was so much solvent that i was working in a blizzard.

I can spray the paint without thinning it as long as the fan control is a 1-2 circle.

When I sprayed clear coat with this gun 2 years ago, I was spraying large sheet metal sections for a fireplace facade. 10' x7' of material. I knew very little about HVLP back then and I'm sure if it was spraying only a dot, I would have given up. I get the feeling something is wrong with the gun.

I can kind of get away with the "small circle" spraying because I'm currently spraying window jambs and trim, but its a pain in the rear.

Especially when I see guys on youtube getting their guns to spray 4" wide patterns with excellent paint coverage.

 

[branimal]

If gun is clean, the first thing to check is if the tip is the proper tip for the material being sprayed. Next up is if the paint is thin enough to be sprayed.

The gun can be setup with a 1.4 needle/nozzle/aircap or a 1.8 needle/nozzle/aircap. I'm using the 1.8.

The nozzles and aircaps are clearly labeled. But the needles are not. And I do admit to possibly mixing them up. But I measured both with digital calipers and im getting exactly the same size on both needles. Across the full length of the needle.

 

[dnschmidt]

Jack up your air pressure. Try 40-50 psig and see what happens. Clearly the air cap horns aren't able to break up the paint sufficiently to open up the fan. Two statements you've made make me give you this suggestion: One is that your running 30-32PSI and the second is that your using a 100ft long hose. You measure your air pressure at the base of the gun with the trigger pulled. Not 100 ft. away at the compressor. You're likely losing at least 10 PSIG in that length of hose. Also, 2 HP 20 gallon is a puny air compressor for an HVLP gun which are typically air hogs. My HVLP SATA's and Iwata's take 15 CFM which is about 3X what your compressor can put out. I have no idea what a Home Depot spray gun requires but I'll bet it's a lot more than the 4-5 CFM your compressor can handle.

 

[Jswain]

If you're thinning it that much and still can't spray more than a circle I would guess that the gun is plugged up internally.

I have a hvlp gun that I've used for years and always have been **** about spraying(lots) of solvent through to clean it at the end, wipe it down so it looks like new etc.

Well I decided to take it completely apart a few months ago and was quite surprised at the amount of paint buildup inside. Watch a YouTube video on how to completely dismantle

After that I would probably try thinning it normally and around ~20psi. Make sure that cheater valve on the bottom of the gun is all the way open, then adjust your fluid valve with the trigger pulled in until it stops then back out 1/2-1 turn and you should be able to run a wide fan

On mine once the needle was removed if you look inside the gun from the front it took a hex to remove the brass part not sure if yours is the same, in behind there and the seats for the needle had the most buildup

 

[dogdog]

disassemble and clean ?

 

[branimal]

Jack up your air pressure. Try 40-50 psig and see what happens. Clearly the air cap horns aren't able to break up the paint sufficiently to open up the fan. Two statements you've made make me give you this suggestion: One is that your running 30-32PSI and the second is that your using a 100ft long hose. You measure your air pressure at the base of the gun with the trigger pulled. Not 100 ft. away at the compressor. You're likely losing at least 10 PSIG in that length of hose. Also, 2 HP 20 gallon is a puny air compressor for an HVLP gun which are typically air hogs. My HVLP SATA's and Iwata's take 15 CFM which is about 3X what your compressor can put out. I have no idea what a Home Depot spray gun requires but I'll bet it's a lot more than the 4-5 CFM your compressor can handle.

I'm measuring 30-32 PSI at the gun with a regulator and the trigger fully depressed. Once I get it set, I remove the regulator to make the gun more agile. And I don't want paint on the face of the regulator. I might install a swivel connector on it so the hose moves more fluidly.

Here are the specs on the husky gun: 4CFM @ 40PSI
The hulk compressor : 8.39 CFM at 40 PSI and 5.77 CFM at 90 PSI

But yeah the compressor is always on when I'm spraying.

 

[branimal]

If you're thinning it that much and still can't spray more than a circle I would guess that the gun is plugged up internally.

I have a hvlp gun that I've used for years and always have been **** about spraying(lots) of solvent through to clean it at the end, wipe it down so it looks like new etc.

Well I decided to take it completely apart a few months ago and was quite surprised at the amount of paint buildup inside. Watch a YouTube video on how to completely dismantle

After that I would probably try thinning it normally and around ~20psi. Make sure that cheater valve on the bottom of the gun is all the way open, then adjust your fluid valve with the trigger pulled in until it stops then back out 1/2-1 turn and you should be able to run a wide fan

On mine once the needle was removed if you look inside the gun from the front it took a hex to remove the brass part not sure if yours is the same, in behind there and the seats for the needle had the most buildup

Spot on - 10mm hex and 8mm hex. I could barely see that until you mentioned it. Pulled the gun completely apart.

I'm thinking about giving the metal only parts an overnight soak in mineral spirits. Or is there a more preferred thinner for the job?

I'm going to pick up the HF HVLP spray gun cleaning kit to clean off the combination metal/plastic/rubber parts with mineral spirits.

Something seems odd on the trigger of the gun. There is only 1/4" travel in the trigger from when the gun is just delivering air to when it's fully engaged in spray mode.

It feels like the air valve needle is too short.

 

[seagravedriver]

I have a HVLP system, and I am a hack at it. My first project were my kitchen cabinets in our old home. Oil based Sherwin Williams. It came out perfect. I used Rooda paint this time, and had a fight from start to finish.

I was told to SOAK it in acetone. It worked well for cleaning, but it does evaporate fairly quick, but it does a great job. I also ordered a cleaning kit for the gun I own.

 

[Jswain]

Looks like quite a bit of dried up paint in there so she should be back to normal after a good clean. Mineral spirits should be fine acetone may work better but I've used both, soak it for a bit then I gently used a little pick to remove the big pieces. Once it's all back together put a little more solvent in the cup and spray it through the gun again and it's ready to go

 

[charger]

That filter that goes in the gun were the cup screws on can cause problems, strain your paint and try it without the filter.

 

[dnschmidt]

Here's the easiest way to tell where the problem is. Take off the aircap. Put some paint in the cup. Pull the trigger. If you get a nice piss stream of paint coming out of the nozzle then the passages of the gun are fine from the fluid point of view. If you put on the aircap and attach the air line and you get no paint then the the problem must be the air passages as that's all that's left.

 

[david3921]

Here's the easiest way to tell where the problem is. Take off the aircap. Put some paint in the cup. Pull the trigger. If you get a nice piss stream of paint coming out of the nozzle then the passages of the gun are fine from the fluid point of view. If you put on the aircap and attach the air line and you get no paint then the the problem must be the air passages as that's all that's left.

This. You should get a steam from just gravity. Make sure the fluid needle is turned almost all the way out. As for the cap, look through it up to a bright light. All of the passages should be clear.

You said that you sprayed clear through it. I'm guessing that the cap passages didn't get cleaned out well enough. I always run acetone through my gun. It cleans up most every type of paint.

 

[EZ_Garage]

In my shop of various HVLP gravity feed guns, limited material being sprayed is often caused by a clogged vent in the cup lid. Fortunately that is an easy fix and it is easy to see if that is what is causing it... just remove the cap all together and see if performance improves...if it does clean the cap vent. For some reason, I'll tear my gun down 3-4 times before remembering to check the stupid cap vent. LOL and I HTH

 

[branimal]

I cleaned out the gun thoroughly and it is spraying great. Thanks for all the help.

 

[Jswain]

Good to hear!

 

[The Cobbler]

sort of unrelated to OP's issue as different guns, I had same problem with a touch up gun, but it was a suction feed. after many times screwing with it, i found the dip tube had a hairline crack in it. it was quite frustrating to say the least.
Glad OP got his issue resolved.

 

[Slednut]

I use the same gun for primer, I didn't look at every post so sorry if this has been covered.

Check the vent on top of the cup cap, it usually takes a pair of pliers to remove it the first time. If it's not removed and cleaned every time the gun is used it will plug up.

BTW when your done using the gun put a little lacquer thinner in the gun and shack and spray the gun, it will clean out the cup and gun of almost all the paint.

Oops, just saw that this was covered.

 

[branimal]

I use the same gun for primer, I didn't look at every post so sorry if this has been covered.



Check the vent on top of the cup cap, it usually takes a pair of pliers to remove it the first time. If it's not removed and cleaned every time the gun is used it will plug up.



BTW when your done using the gun put a little lacquer thinner in the gun and shack and spray the gun, it will clean out the cup and gun of almost all the paint.



Oops, just saw that this was covered.

Do you spray lacquer thinner at the end of your cleaning process regardless of what you sprayed? Is lacquer thinner the best cleaning solvent?



I see you have the Husky two gun kit. You get a case, two guns, extra cups, cleaning kit, plus two pressure gauges. Killer deal IMO. I don’t think HD had this kit back in 2018 when I bought mine gun.

 

[dogdog]

They have spray gun cleaners... even at HD... or better ones at your local automotive paint supply place... very acidic at least the one I got. Even HF have one in spray can... but too costly. I have those thin stainless steel food serving things with a lit for $10 from the restaurant supply stores to use as a basin.

https://www.homedepot.com/p/Klean-Strip-1-Gal-Paint-Sprayer-Cleaner-GKSP750/304679871

 

[Slednut]

Do you spray lacquer thinner at the end of your cleaning process regardless of what you sprayed? Is lacquer thinner the best cleaning solvent?



I see you have the Husky two gun kit. You get a case, two guns, extra cups, cleaning kit, plus two pressure gauges. Killer deal IMO. I don’t think HD had this kit back in 2018 when I bought mine gun.

I only paint cars so yes I always use lacquer thinner, I do the shake spray first before I take the gun apart. Make sure you spray before shaking or you can get thinner in you eye coming out of the vent hole if your not wearing eye protection.

Also make sure you don't get any lacquer thinner on the gauge, it will ruin the clear plastic cover.

My friend gave me the kit after I built him some cabinets for his shop, I ordered a 1.8 tip for epoxy and urethane primers. I use a Black Widow gun from HF for base and clear coats.