# matching a compressor to hvlp sprayer



## romes_32 (Feb 21, 2009)

Hi all, 

I have a Husky 790 HVLP sprayer. I'm trying to figure out what size compressor I need in order to properly spray my projects. Normally I do small projects like chairs, 5-dressers, etc. On the sprayer it was 40psi/2. 2.7bar MAX. Any help would be appreciated.


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## mdntrdr (Dec 22, 2009)

Your compressor needs to meet, preferably exceed, the CFM requirements of your gun. :smile:

What is the CFM requirement?


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## del schisler (Nov 5, 2009)

romes_32 said:


> Hi all,
> 
> I have a Husky 790 HVLP sprayer. I'm trying to figure out what size compressor I need in order to properly spray my projects. Normally I do small projects like chairs, 5-dressers, etc. On the sprayer it was 40psi/2. 2.7bar MAX. Any help would be appreciated.


QUOTE=romes_32;178124]Hi all, 

I have a Husky 790 HVLP sprayer. I'm trying to figure out what size compressor I need in order to properly spray my projects. Normally I do small projects like chairs, 5-dressers, etc. On the sprayer it was 40psi/2. 2.7bar MAX. Any help would be appreciated.[/QUOTE]

I spray lacquer and use a 2mm nozzle with 30lbs of air . Here is one that will work. Price $379 http://www.homedepot.com/buy/tools-hardware/air-compressors-tools-accessories/husky/2-0-running-hp-30-gallon-vertical-compressor-62579.html


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## cabinetman (Jul 5, 2007)

mdntrdr said:


> Your compressor needs to meet, preferably exceed, the CFM requirements of your gun. :smile:


+1.












 









.


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## mdntrdr (Dec 22, 2009)

Earlex is a turbine system, totally different from conventional air. :smile:


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## Tony B (Jul 30, 2008)

"(/QUOTE)Jorge.......I am having a heck of a problem spraying lacquer with HVLP, how viscous is your solution? Am I diluting too much? I get a lot of lacker in the middle and the banding on the sides, even if I overlap half way through the previous pass. I am using an Earlex spray station with a 1.5 nozzle. Any help would be appreciated.[/QUOTE]"

I have the Earlex 5000 Spray Station Pro.
Different paint manufacturers use slightly different percentages of solids. I use a Pre-Cat lacquer of about 20% solids by volume/27% solids by weight. The 1.5 tip is way too small. I use the 2.0 and even at that, I thin by at least 20%.


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## jack warner (Oct 15, 2010)

any 20 gal 2 horse will work fine. i would not use anything smaller than 20 gal. air copasity is as important as cfm's


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## Tony B (Jul 30, 2008)

JorgeG said:


> "
> Thanks Tony.......Don't know if I can find out the solids content, they are not big on MSDS here...:sad:


An MSDS wont be of much help. It only contains safety data. Look up your product on the internet and when you find it, look for a PDS (Product Data Sheet) or Technical Data Sheet. Sometimes you will get some info from a spec sheet. 
The best method is to spray on some scrap plywood. Try at 10% Thinner, 20 % etc, and work up to about 30% and see how the lacquer lays out. Dont laugh, I use a good size screwdriver. I dip it into the lacquer/thinner mix, pull it out and look at how fast it runs off of the screwdriver shaft. After a while you will find your own method of 'testing' the viscosity. The screw driver method works for me. 
Sorry I cant be of more help.
.


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## romes_32 (Feb 21, 2009)

I'm looking at the manual and it says 6.2 Ave or 8.9 countinuous [email protected] psi. However, it says NOTHING about what the minimum air compressor size you can paint with.


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## cabinetman (Jul 5, 2007)

JorgeG said:


> Del, I don't want to high jack the thread, but I am having a heck of a problem spraying lacquer with HVLP, how viscous is your solution? Am I diluting too much? I get a lot of lacker in the middle and the banding on the sides, even if I overlap half way through the previous pass. I am using an Earlex spray station with a 1.5 nozzle. Any help would be appreciated.


Check with the specific brand of lacquer you're using. Some say "ready to spray", and then some require 50% thinning with lacquer thinner. You might just fiddle with the pattern, which could affect where in the spray pattern is too much concentration. Do the same with fluid, and air control. 

Practicing on some cardboard may give a good indication of exactly what the pattern and consistency is.
Use a lot of light so you can see what you're doing. The distance from the object, and the speed of making passes all work together. It may just take a bit of practice.












 









.


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## Tony B (Jul 30, 2008)

JorgeG said:


> So, what happened Tony? did you loose the cup they send with the unit or is it just worthless? :smile:
> .


I generally don't believe in jury rigging. I believe we should use products as they were meant to be used. The viscosity cup is an exception for me. I tried using it when I first get the gun because I am big on following instructions. In this case, I just couldn't get the material to flow like I wanted it to. From over 30 years of spraying, I just know what works for me. By all means, use the viscosity first and see how it goes. I assume that if you are here inquiring, it ain't working for you either.


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## Tony B (Jul 30, 2008)

*A note on HVLP*

If you never sprayed before, HVLP is easy to learn. 

If, on the other hand, you have spraying experience, HVLP spraying can take some getting used to. When using conventional guns, we get feedback as to what is happening. You can hear the hiss of the air and fluid leaving the gun and see the 'wall' of paint progressing forward. With HVLP, you dont hear much hissing and since you are using low pressure the 'wall' of paint moving along dont seem as thick because you are not seeing all of that bounce back of fluid. Thus - the lacquer goes on thicker than you want. 
I always use a scrap of plywood to test my pattern. With conventional spraying, I set my pattern and 'rock and roll'. With HVLP you have to pay a little more attention and litterally memorize the spray pattern and thickness and go on faith. Dont look back, just spray.
One more note on the Earlex. You really cant adjust your spray pattern, only the flow rate. The instructions say to adjust the spray pattern, tighten or loosen the air cap ring. This is a joke. 

*Jorge*, is it possible that you have the incorrect tip and needle set-up? You might want to check this. Make sure that you have the 1.5 needle with the 1.5 tip. I have made this mistake once when changing the set-up. Thought I would never figure out what was wrong. I had accidentally had the 1.5 needle and the 2.0 tip set up in the gun. The needle and tip size are stamped on those parts. I dont think they are stamped on the 1.5. Wont take but a minute to find out.


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## romes_32 (Feb 21, 2009)

Also, what do you use as far as thinning paint. I have been doing 4oz water, 4 oz floetrol, 16 oz paint. Is that too much, too little?


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## JCCLARK (Jan 30, 2007)

Things to rememember.
Most HVLP guns use more air than most 110 volt compressors 
can deliver. But conventional guns use a lot less and do fine.

The CFM rating to watch for on a compressor is the 90 psi one.
Compressors are always compressing against the tank which is
90 psi or higher. They seldom see 40 psi to pump against.

Tank size won't help much. once it starts running, it
will keep running till full. Only CFM output
can allow it to catch up and stop. 
It must be more than you're useing to stop.
It'll take loger to come on with a larger tank
but it'll also take longer to refill.

You want it to run as little as possible, the longer it runs,
the hotter it gets, which gives you moisture problems.
So the bigger the better.

Never compare compressors by HP. CFM is the true indicator.
Mfg's stretch the HP numbers, if you want to know the true
power, compare the amp rating of the motor.
That's the true power of the compressor and it
can vary greatly by brand. But the CFM to Amp ratio
holds pretty consistant from brand to brand.
You usually get what you pay for.

If you use HVLP you really need bigger fittings more than
you need a bigger hose. The std 1/4" air fittings really
restrict the air CFM's.
The female quick disconnect fittings narrow down to a
hole smaller than 1/8" dia. That's the bottleneck.
Home Depot sells 3/8" fittings that connect to std 
1/4" air hose, the quick disconnect hole is twice as big.
Otherwise you need to run over 60 psi to the gun and
regulate down there to get enough CFM through the 
disconnects to the gun.:smile:


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## romes_32 (Feb 21, 2009)

*need new compressor*

so I bought a husky 20 gallon compressor and was spraying poly on a project with an HVLP sprayer when something busted in it. I took it back to the store to get repaired. They called me a week ago to say it needs a belt and the part is on back order... well, total time from tool turn in to now has been a month and I don't have a firm time as to when I'll get it back. What's a good price for a decent one? $200? $300? $400?


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