HVLP paint gun requirements

[Kyle Chandler]

Hey guys,
So I'm going to be painting my SN and RN, and I'm looking at buying this Devilbiss HVLP kit...

https://www.amazon.com/DeVilbiss-80...21555&sr=8-2&keywords=devilbiss+spray+gun+kit

Now my air compressor doesn't meet the requirements. Its a 20 gallon, 6.3 cfm @ 40 psi. Can I get by? Will I just not be able to paint for long durations? I guess I'm just wondering how my paint will turn out if I use this gun with my compressor.

Thanks!

 

[Mike W]

Looks like the same kit I have. That Gun works pretty good but if your air compressor won't keep up you will just need to pause until the pressure builds back up. I would recommend you upgrading your compressor but you might be able to get by with the one you have.

 

[Kyle Chandler]

Thank you. What compressor do you have? Will there be any real drawback to pausing, then starting again?

 

[Mike W]

Not sure how big my compressor is but it has no problem keeping up. If you have to pause briefly to let tours catch up it shouldn't be a big deal.

 

[Kyle Chandler]

great thank you. Thats mainly what I was wondering.

 

[Zero Client]

You won't know until you run some tests through the gun. I suggest blowing WATER through it to check your spray patterns and test your compressor. It's easy to dry out after (no issue). Spray water on the side of your house.

Paint mix should be about 4:2:0.5 paint:reducer:hardener but ymmv.

Also make sure you run straight from your tank to your gun - i.e. No regulator nor filter at the tank side, and put one of these filters inline just before your gun's regulator. This should keep flows higher.

Buy these inline filters and attach to your guns. They worth their weight in gold.
ATD Tools 7812 Spray Gun Filter, (Pack of 3) https://www.amazon.com/dp/B00KMKS1L8/ref=cm_sw_r_sms_c_api_2xJ-xbMXH1SAX

Last, make sure you drain your tank of all water/ moisture. Most tanks have a petcock drain at the bottom. You'll be surprised at the water/oil/dirt mix that accumulates.

Pm me if you need sanding techniques. Make sure you buy about 4 tack cloths.

 

[Zero Client]

Also watch the gauge on your gun while you are test spraying. The pressure drops when spraying and the issue with low cfm tanks are tgat it can't keep up with the guns pressure requirements. It helps to run shorter & wider air hose from the tank to the gun to fight pressure drop. Get sone 1/2" air line.

If the pressure drops too much you'll know your tank cannot recover the pressure in the lines; even well before it kicks back on the first time. Flow is flow almost regardless of tank's current pressure. Again keeping the line pressure above 40 is your best bet at combating pressure drop. keep the gun pressure at 40 to start. If you want you can put a second gauge inline on the guns supply line to see how efficient your tank is at keeping unregulated air flow in the air line. For instance keep your air line at 120psi static, and the gun at 40psi static.... then when you spray the high pressure line should stay above your gun's pressure setting. It the high pressure side drops below 40, well; your tank is too small.

I got by with my 10cfm tank which was about my minimum imo.

 

[Kyle Chandler]

Ok thank you this helps a ton! I'll get a different air hose because the one I have is long and small. So just having one inline filter is enough? Also if I have to stop and let compressor catch up, would that be an issue in your opinion?

 

[SmittySX]

Subd

 

[Zero Client]

Yes those little red filters should be enough. They trap water and oil to eliminate fisheye.

Also don't think you'll want to try higher air pressure at the gun at any point. You may think this will help with flow rate but what it will do is over-atomize and dry the paint too much before it reaches the finish. Pressures got to be low. If it's too high the paint will dry and fuzz up the finish in mid air - like Powder. In my experience primer tends to do this more than paint which is why primer nozzles are usually larger than paint nozzles - but pressure can atomize as well.

You'll know a lot more after you prime as you'll need to sand the primed finish anyhow.

 

[Zero Client]

You'll only have to stop when the line pressure can't keep up with the guns demand.... aka if the tank drops to 80psi and all of a sudden the gun drops to 25psi - you'll know to stop and wait for recovery.

Set your gun static pressure to 40psi, and if it pressure drops below 30 when in-use then your tank is too small. Again all these tests can be done with water sprayed on the side of your house while checking spray patterns, making adjustments, and not making a mess. In my experience once you have a feel for water spray patterns the paint will only take very minor adjustments.

 

[Zero Client]

Here's my backyard spray job.

If you choose to spray outside instead of in a booth it helps a bunch to wet the ground 20feet around the ski to help trap anything airborne.

I ran my sprinkler system for 15 minutes.

 

[Kyle Chandler]

Ok makes sense.

Paint looks awesome. Is that single stage or base/clear?

 

[Zero Client]

Single stage. Omni Chrysler 9700 4:2:0.5 mix

 

[Kyle Chandler]

Alright thanks. I was thinking I was gonna do base/clear, but that looks really good. How's it holding up?

 

[b-rad]

9700 is black !but I would by ppg instead theres more solids in it and a better paint !