harbor Freight HVLP Question

[BenWillis]

Ok so I have one of the HF knock off hvlp guns and wonder if my compressor is big enough to run the gun. My compressor is a CH 20gal 5hp 125psi with reed valve pump.

When spraying primer the material delivery was far less than adequate. What would have taken me 15 minutes with a siphon gun took nearly an hour because I had to go so slow over the surface. The compressor only kicked on occasionally so I think I have enough pressure but what about the CFM? The gun asks for 9.5 cfm and I think my compressor puts out 6.5.

Any help would be greatly appreciated.

Ben in SC

[Len]

You will probably have enough air pressure and CFM to do a small amount of spraying but with a 20 gal. tank you'll probably see a drop in pressure after spraying a panel or two. Spraying an entire car is probably out of the question.

Keep an eye on the pressure as you spray, if you see it start to drop you'll need to stop and wait for the compressor to catch up. When you need to stop spraying during the application of your top coats you can generate dull areas because the paint on the surface tends to dry at the point where you stopped the application. A larger tank would allow you to go further before your pressure drops. If you try to keep spraying at a reduced pressure you will generate even more texture problems especially using an HVLP gun.

[Steve g]

CFM has to do with the out flow of the compressor. If it's not running and you're having a problem with your painting, the problem is not with the compressor volume. Inadequate hose size could restrict the cfm flow to the gun, but obviously since the comp is not running it's not a matter of the compressor not keeping up with the gun, and I doubt very much it's air volume at all that is your problem.
I suspect that your problem is the tip size on the gun when spraying heavier materials. I bought a cheap Porter Cable gun that came with a 1.5 tip. I used it for everything, base, clear, epoxy and high build 2 k primers. Works okay, maybe even well, with the base, clear and even the epoxy when thinned, but woefully inadequate when shooting heavier primer. Recently purchased a 2.0 tip because I wanted to shoot polyexter fillers and dedicate this as my primer gun, and what a difference. I am now moving my gun at the same speed I would with the lighter materials in the 1.5 tip.
Steve g.

[BenWillis]

Thanks for the reply Len.

The compressor actually only ran periodically during the spraying of the bottom of the car. The problem I was having is with the primer application.

Maybe I dont have the gun setup right? With the primer atomized there just isnt enough coming out of the gun to paint at any speed. With more flow the paint droplets are to big and it almost spatters.

Any suggestions?

Thanks Again!

Ben

[Len]

I think Steve has the answer. If the tip is too small for the viscosity of the material being sprayed you won't get enough flow from the gun to do the job properly.

Another factor is that inexpensive guns are usually not engineered or machined as well as better guns and the same tip size on a better gun could produce an entirely different result. This would probably be due to the fact that (on a better gun) you would PULL more of the material out of the gun with the flow of air from the air cap.

[BenWillis]

The tip is a 1.4 on this gun. One other thing I notised was that the flow would look good for a few second then it would die off. I have 25' of 1/2" line on the compressor.

I am tempted to go out and get a bigger compressor today but would hate for that to not solve the problem. I am spraying MP182 right now. Maybe it started setting up int he cub and got to thick?

Ben

[Len]

If the air intake to the cup is clogged you may be stopping the flow of material to the tip. Check the hole in the cup's cap to make sure it is open. This is usually the problem if the gun starts out ok then the material flow becomes less and less.

[keb1]

I had the same problem.
I knew my 80 gallon 2 stage compressor was not it.
I tried reducing (thinning out) the filler and that didn't really help.
(it still spit not sprayed)
Len is right...........
First - Make sure paint that the hole in the paint cap cup is open.
Second - Break down and buy a gun with at least a 1.7 tip for shooting 2K style primers.
What a difference.....
The stuff just flows on,fills small imperfections and dries as flat a pancake

[BenWillis]

Great! Now I need to see if I can order a larger tip for this gun... Are the nozzles made specifically for individual guns? What would be a good source for an inexpensive nozzle for this cheap gun?

Thanks for the ideas!

Ben

[Phil V]

I'm pretty sure you can get several different tip/air cap sizes for your gun right from Harbor Freight. Go for a tip between 1.9 - 2.1 size for shooting 2-K primers. Better yet just go buy a cheap siphon feed conventional asian knockoff gun (non hvlp) for around $20 - $25 and use it for 2-K primer only.
If you were near me here in Michigan I'd give you an old gun for nothing that would do a good job with 2-K primer. A 1.4 tip is just too small for shooting primer that thick. Keep in mind that everytime you shoot 2-K or epoxy primer with that HF gun you are going to have to totally disassemble that gun (or any gravity feed HVLP gun) clean all the parts individually with lacquer thinner then reassemble the gun. Sloshing thinner around in the cup and shooting thinner for a couple seconds don't get it with those type of guns. They will plug up quickly if you don't totally clean all the part that come in contact with primer.

[Phil V]

What brand and type of paint do you plan on using to spray your car ?(assuming you are working on a car/truck). That HF gravity feed HVLP gun is not a good choice of guns for spraying BC/CC, you will be disappointed with the results if you use that gun to spray BC/CC.

[BenWillis]

Phil,

This is actually my second paint job on a car. I painted a Porsche 911 four years ago and used a siphon gun from Lowes. It was a bc/cc job using PPC Concept.

On this car (1960 Austin Healey Sprite) I'm going with PPG again but a single stage. I just dont think that bc/cc looks good on the old cars that orginally had laquer.

I'll give HF a call tomorrow to ask about the nozzles.

Thanks!

Ben in SC

[trent]

Let me know if HF makes a larger tip. I think I have the same gun as you, that I use for a primer gun.

[Ron H]

I have the same gun. Epoxy primer seems to flow slowly for me also. I did work better when I turned the air up 35 to 40 psi. I have a 60 gal 7.5 HP, so I don't think it's the compressor. I called HF, no other tips available. I called then the paint manufacturer, the tech told me to thin up to 4:1:3 tech sheet said 4:1:1/2. He said a mix of 4:1:1 would probably do it. Will thinning the 2K primer be counter productive? Sounds like I need to buy another gun to do my paint anyway.

[reflections7]

Im sure you did this but let me remind you. Those guns come with the tip and aircap not tight. This will cause the intermittant spraying. Make sure they both are tight and try again.

[John in Mich]

Are you guys talking about the HF "purple gun" (#43430)?

[Ron H]

Yes, The purple gun w/20 oz cup. HVLP

[BenWillis]

I have the same gun. Epoxy primer seems to flow slowly for me also. I did work better when I turned the air up 35 to 40 psi. I have a 60 gal 7.5 HP, so I don't think it's the compressor. I called HF, no other tips available. I called then the paint manufacturer, the tech told me to thin up to 4:1:3 tech sheet said 4:1:1/2. He said a mix of 4:1:1 would probably do it. Will thinning the 2K primer be counter productive? Sounds like I need to buy another gun to do my paint anyway.


I called and spoke to customer service. They make an "accessory kit" for this gun and you can get new nozzles 1.5 - 2.0 for $12.95 each.

I ordered a 1.7 and 2.0

Ben in SC

[Ron H]

Great news, I just called the local store here in Texarkana. Should have tried the national number myself. Thanks

[cbrman]

Well I will try to chime in on this one. I sprayed a 72 pontiac catalina this weekend using 2 hf hvlp guns and a binks m1g.

I will tell you first hand as well as many people on here... you get what you pay for when it comes to tools.

I picked up two of the cheapo harbor freight guns to use for primer/base coat. I also am limited on compressor size so that is why I went with the binks m1g hvlp gun. I was able to spray at the local air force hobby shop this time so compressor output was not a problem.

I used the harbor freight guns mainly for primer this time, but in the past I have used a brand new one for a complete basecoat/clear coat using dupont chroma supplies. I used the brand new one when I sprayed a friends zx12 motorcycle and It produced adequate results. There was alot of orange peel in the clear cause the gun doesn't atomize the material very well. The second use I broke the gun down and completely cleaned it out. I sprayed primer with one of the guns (1.4 tip) and it sprayed ok. I know the tip is small, they sent me the wrong one and wouldn't take it back. The other 1.4 I used for base and was going to use my binks for clear only. I must tell you the 1.4 hf gun was spraying splotchy. I could not get an even coat with it unless I went really slow but it still sprayed kinda crappy. I mixed up a coat of clear with blue pearl in it and sprayed it. It would either spray really dry or I would have to go really slow and lay it on thick. The clear was coming out as forrest gump would say 'in fat rain drops'.

I got a couple of runs with it and got very discouraged cause it was not laying evenly. I switched to the binks for the clear and it layed on like glass. I was sooooo surprised.

I tried the m1g at anything from 8 psi to 45 psi and it atomized and layed on smooth as a baby's bottom. Obviously you would get a cloud of overspray at 45 that was pretty good. I tried the hf guns at 10-40 and they wouldnt spray much if anything at lower pressures. I had to run em at 35-40 all day and it literally took all day to spray with em.

In all honesty, save your money and get a better gun. I have sprayed with 5-10 knock off guns over the past few yrs of painting (as a weekend hobby only). My experience is they are ok for primer if you plan on sanding. Otherwise get a better gun.

This was the first time using my m1g. I didn't want to spray base and clear in it as I intended it only to be a clear gun. My plans for future paint work is to spray everything but primer with my m1g gun.

I know everyone is going to say it is all about gun setup. I have purchased len's spray painting 101, a hobby air fresh air system and various other supplies as well as learn from many on here... I had the resident painter stop by and he even looked at the gun and said it was tuned properly but it just wasnt spraying very well.

Take it for what it's worth.

Note in the pics, image 1 shows me spraying clear with the m1g. Image 3 shows me holding the hf gun with the metallic grey basecoat.

Steven

[BenWillis]

Well I just came inside from spraying three coats of PPG Concept Urethane on the bottom of my project and I'll tell you that gun setup does make a difference.

So far it looks like I have minimal OP and a VERY good shine. The paint flowed out beautifully and sprayed very fast. The 1.4mm tip is perfect for the top coats so I have decided to pick up another gun and 2.0 tip for shooting primer. Until then I'll just use my older siphon guns for the primer.

Thanks to all who helped with my issue! I just love this site, the new forum makes it MUCH easie to navigate!

Ben in SC

[BenWillis]

For those interested here's a picture from this morning. I'm very happy with the results.

Ben in SC

http://www.tri-countyrc.com/galleries/bug_gallery/first/index.html
http://www.tri-countyrc.com/galleries/bug_gallery/enginepull/index.html
http://www.tri-countyrc.com/galleries/bug_gallery/blasted/index.html
http://www.tri-countyrc.com/galleries/bug_gallery/paint/index.html


http://www.tri-countyrc.com/galleries/bug_gallery/paint/bigimages/IMG_3190.jpg

[Josh]

Hey, Ben!

I just joined the bbs; looking to go the inexpensive route for repainting my cars!

Do you have the part number or numbers for these tips which you've ordered? I've been trying to comprehend the whole HLVP cfm @__psi thing, myself; it's quite daunting.

I've got the same compressor, I think; a Sears 20 gal 4.5hp horizontal tank, with 8.4 cfm@ 40psi; 6.2 cfm@ 90psi. Part number/model number is 919 164200.

[BenWillis]

Hey, Ben!

I just joined the bbs; looking to go the inexpensive route for repainting my cars!

Do you have the part number or numbers for these tips which you've ordered? I've been trying to comprehend the whole HLVP cfm @__psi thing, myself; it's quite daunting.

I've got the same compressor, I think; a Sears 20 gal 4.5hp horizontal tank, with 8.4 cfm@ 40psi; 6.2 cfm@ 90psi. Part number/model number is 919 164200.
I ordered a 1.9mm tip, the part number was #25943 and the cost for the "kit" was 29.57.

They also had a 2.2mm tip #25942.

Good luck Josh!

Ben

[Josh]

My 43430 model Harbor Freight purple paint gun's 1.4mm tip is stuck in the housing; the included "tool" doesn't fit the nozzle very well. It just spins off, and can't grab the nozzle tight enough to unscrew it.

I'd advise folks who're in the market for this gun to open the package at the store, and make certain that not only everything is there, but that the nozzle can be unscrewed from the housing with the included tool. The guns are boxed but not sealed in plastic, so you can check through the boxes until you find a gun that's not got a stuck nozzle.

Now i've got to drive another 40 miles round trip to take this thing back!

-Josh

[shall36]

Hey there...I was getting ready to shoot some DP40 with this gun. The Psheet says a 1.4 - 1.6 mm tip can be used and to set 8 - 10 psi at the cap.

As noted earlier, the HF 43430 gun has a 1.4 tip. Anyone have experience laying on DP40 with this gun?

Also, there are no markings on the gun nor is there a table in the instruction book (which is a joke) regarding the proper inlet setting to achieve 10 psi at the cap. Anyone have a reference for this? I guess the standard is 29 psi at the inlet translates into 10 psi at the cap.

I'm considering buying a new gun to lay down DP40 and K36. I'll have someone shoot the color for me. Any suggestions on a good gun and tip sizes...reasonably priced?

[Phil V]

30 - 35 psi is in the ball park for that gun.

[Phil V]

I should have clarified that its 30 - 35 psi with the trigger pulled all the way back and air flowing through the gun when you set the inlet pressure on the gun.

[shall36]

Thanks Phil!

[chrisri]

FYI and future searches:

Larger nozzles for the HF 43430 and 38308 guns have to be ordered by phone or from their printed catalog. The sku for the 1.9mm is: 25943-0vga and is up to $35.89 now. I never did buy the bigger nozzle to spray my two part heavy build primer... just used the 1.4 slowly and sanded the heavy orange peel as needed.

I had the same problem as Josh trying to get the nozzle off... until I realized that it has a left handed thread.

[spiffitz]

I had the same problem as Josh trying to get the nozzle off... until I realized that it has a left handed thread.Doh! I already broke the tool trying to get the nozzle off. Now I need to find my extra one somewhere.