Suitable Compressors and Spray Guns

I covered all that compressor and gun stuff here.

http://clstunt.com/htdocs/dcforum/DCForumID9/59.html

>I covered all that compressor and gun stuff here.
>
>http://clstunt.com/htdocs/dcforum/DCForumID9/59.html

Thanks! I searched first, but not the Product Reviews. I always look first before asking, but I have a real knack for missing stuff with search engines!

I found that 5 gal compressors can maintain 30psi for no more than 1 minute. I bought an 11 gal storage tank and hooked it up in parallel to the compressor. Now I can put a coat of paint on the entire plane in one sitting. No more paint one wing panel, wait, paint secont panel, wait, etc...
I would highley recommend getting one. It's cheap and makes painting more convinient. Just don't over do it by getting a 30 gal one.

Hi Steven,

That's why it's important to have a regulator on the gun. I set my compressors cut-in pressure at 40-50 psi and cut-off at at 110 psi. The compressor feeds a moisture trap/regulator unit and I set it a few psi lower than my cut-in pressure so there are no surges to the gun when the compressor kicks in. Depending on the viscosity of the paint, I set my gun's regulator from 15 to 25 psi. So the compressor kicks in now and then, who cares .

Jim Womack

Jim,
I have a pressure regulators on the tank and the compressor feeding into moisture trap bollowed by a another pressure regulator. I use Harbor Freight's gravity fed touch up gun as per original article. Instructions for the guy call for 40psi to spray. Perhaps that's too much. I've sprayed at 25psi before but wasn't 100% sure that that's the pressure to use. It did take longer before the compressor kicked in at 25psi than 40psi.

I originally bought Pasaache(is that the right spelling?) gun and it took me forever to put a single coat of paint on. Thanks to the information I found on this forum, I switched to HVLP gun and never looked back!

Did I ever mention that this forum is a Gold Mine!

>Did I ever mention that this forum is a Gold Mine! <

I'll second that! Great advice. The obvious lessons I take away are:

1) You can't have too much tank volume, and 20 gallons and up is where you want to live. Clearly this is a big factor for HVLP guns.

2) If the maximum pressure is in the 115 psi range, which is typical, you can use whatever gun you want, HVLP or LVHP. The compressor can handle either.

3) A regulator and trap for oil/moisture are an absolute must (I knew that already--I work a lot with compressed gases at work).

Many thanks for the detailed recommendations. This is just the type of information I need to make good equipment choices. The only down side I see with the large tank volumes is the increase in required space to store the unit.

concerning the Harbor Freight stuff, some of what they sell is junk (as it is some stuff in many other stores) but much of it is quite good (or at least good enough for our purposes).

Although most prices are quite reasonable, you will find a lot of things on sale, were on sale, or will be on sale. If you have a store near you they often have things on sale that the web site does not list as such. You might also ask if something that isn't on sale will be (or was. They might honor it if you live out of town, etc.) Also, what is on sale on the web site may not be on sale at the store, but if you pring out a copy of the web ad, they will honor it.

Hmm, this sounds like a commercial, doesn't it?

On the original question, compressors have come down in price recently. Even Wal-Mart has good prices (especially sale prices). Just make sure you have a tank and air flow capacity large enough to do the job you plan to do with the size gun you plan to use. If the tires take longer to air up, who cares? Just get the size you need for spraying. You probably won't wear it out in a lifetime (unless your tires go flat a lot).

We moved into a house once that had become bug infested due to dog food being stored in the basement. I "discovered" that it was cheaper for me to buy a compressor and spray gun and eradicate the bugs myself than to hire the Orkin man. And it was just as effective. Bugs gone, spray gun here. That was a number of years ago, but, well, the tires do need airing, too. And these days they charge you a quarter at the gas station.

Hi Andrew,

If you're on a budget, or just cheap (like me) I can recommend the 3HP pancake compressor sold by Homier.

http://www.homier.com/itemdetail.asp?i=03941&browse=no

I have a 220v 6hp 25 gal compressor but it's overkill for a lot of things that I do. Besides, it's semi-permanently installed in my barn/workshop. The pancake compressor is ideal for most anything you might do with the exception of tools that operate at higher psi settings (impact wrenches, air ratchets, etc)and it's mobile to boot. I also use it to air up my crown stapler and coil fed framing nailer. It's a good, servicable compressor.

As for a HVLP sprayer, take a look at this one. It's nearly as good as the Harbour Freight gun (it doesn't have a gun mounted regulator) but it's only 20 bucks. I have 3, they all work well.

http://www.homier.com/itemdetail.asp?i=02541&browse=no

Get a regulator for the gun (2 bucks):

http://www.homier.com/itemdetail.asp?i=04574&c=10

I just bought a nice HVLP touch up gun from Homier too:

http://www.homier.com/itemdetail.asp?i=02729&browse=no

I used to buy a lot of my light-use tools and stuff from Harbour Freight but Homier also has traveling tool sales and they get out to my area 4 or 5 times a year. I can save a bundle on shipping charges if I buy my stuff when they are in town.

Cheers,

>Hi Andrew,
>
>If you're on a budget, or just cheap (like me) I can
>recommend the 3HP pancake compressor sold by Homier.
>
>http://www.homier.com/itemdetail.asp?i=03941&browse=no
>
>I have a 220v 6hp 25 gal compressor but it's overkill for a
>lot of things that I do. Besides, it's semi-permanently
>installed in my barn/workshop. The pancake compressor is
>ideal for most anything you might do with the exception of
>tools that operate at higher psi settings (impact wrenches,
>air ratchets, etc)and it's mobile to boot. I also use it to
>air up my crown stapler and coil fed framing nailer. It's a
>good, servicable compressor.
>
>As for a HVLP sprayer, take a look at this one. It's nearly
>as good as the Harbour Freight gun (it doesn't have a gun
>mounted regulator) but it's only 20 bucks. I have 3, they
>all work well.
>
>http://www.homier.com/itemdetail.asp?i=02541&browse=no
>
>Get a regulator for the gun (2 bucks):
>
>http://www.homier.com/itemdetail.asp?i=04574&c=10
>
>I just bought a nice HVLP touch up gun from Homier too:
>
>http://www.homier.com/itemdetail.asp?i=02729&browse=no

Bill has some of these guns. Normally I do not like to pooh-pooh other peoples recommendations but I see no comparison between it and the Harbor Freight guns. Hey, what do you expect they are all made in Tawian.

LAST EDITED ON Aug-13-03 AT 09:34 AM (CDT)
 
As far as compressors, a 3 HP 20 gallon should be the standard. I did used to have a 5 gallon, but for another $100 the world completely opened up going to the 20 gallon.

I definitely agree with 'zilla. My wife gave me a 4.5HP/20 gallon Craftsman compressor for Christmas ten years ago and it works great. The larger tank means the compressor doesn't cycle on and off as much during a session. Parts and service are available anywhere.

I have over thirty years experience with my Badger guns and I also think they do a great job. Use the 400 single action for the big stuff and the 150 IL double action for the small stuff. If I take care of them and they should outlive me.

If you buy good stuff, you only have to do it once.

Ron King

I agree with TOW. A 20 gal makes things much more versatile(sp) I use mine for spray painting my models, vapor spray cleaning my car engines, lawn mower engines, Blowing lawn clippings from the mower deck and a whole host of other things like powering a nail gun (staples) when I replaced the roof shingles on my house. OH yes!!! I also air the tires occasionally for the wife .

Bigiron

Zilla,

I have the Harbour Freight gun too and I agree that it is a better quality gun. I'd consider it to be more of a professional or heavy duty gun. However, the Homier guns that I have do a respectable job and are cheap enough that someone on a budget could own several without breaking the bank. Heck, I even painted my truck with one several years ago, came out fine. I still think it's a good deal for someone on a budget or for light or infrequent use.
As for compressors, I generally prefer working with the larger (20+ gallons) ones. I like the portability of the smaller pancake unit, but I wouldn't have it as my primary compressor. And I will second Curt's advice on motors and current useage. My 5 horsecompressor is dual voltage, 115/230. It's pretty much unusable on a 30 amp circuit at 115v. The current draw at startup is just too much for the breaker unless the cut-in pressure is ridiculously low.

Everything these guys already said--basically bigger is better. A couple of thoughts in addition:

The oil-less compressors direct drive types are typically VERY loud.

The HVLP guns consume ALOT of air. I believe the mid size HVLP harbor freight gun that Godzilla has reviewed specs at about 13 CFM at 43 PSI. This is alot of air for anything less than a 5HP compressor. My 1.5 HP unit with 5 gal tank coupled to a SIXTY gallon reservoir tank holding at 75 PSI could not keep up with this gun. It was fine for the base coats and primers, but for the clear, it needed to get entry air up around that 40 + PSI number and I had to go to work and use the big air system to get it to really work well when coating the whole plane. Small parts are ok while the tank holds out.

I would get the biggest unit you could afford and run from 220 single phase. About 5 HP---if you want to use a standard or mid sized HVLP gun. THe HF HVLP has been reviewed on the autobody forums as a particular air hog. But my Binks conversion HVLP Mach 1 gun requires 14-15 CFM at 50 PSI also.

For using a conventional touch-up gun or a mini HVLP, the 2-3 HP units will be fine.

Also, dont get confused by Peak HP, etc. Look at the motor current and voltage specs. Remember 746 watts is one HP. Watts (power) is current times voltage. You cant run a 5 HP compressor on 115 volts in a normal residence.

example: 5 HP is 3750 Watts. If voltage is 115V, current would have to be 32Amps. Not gonna happen.

If you use a 20amp circuit dedicated, at 115V the max power available will be 20 x 115 or 2300Watts. this is only 3HP. And thats theoretical with no losses.

Anyway, Probably more than you wanted to know.

PS: I really DO like that HF gun and plan to review it in a little more detail for SN.

>The HVLP guns consume ALOT of air. I believe the mid size
>HVLP harbor freight gun that Godzilla has reviewed specs at
>about 13 CFM at 43 PSI. This is alot of air for anything
>less than a 5HP compressor.

Ah yes, but we only use the gun at around 5-10 PSI.

My 3 HP Cambell Hausfield single phase 110 volt never starves shooting paint. Maybe running a DA or a buffer is right on the edge.

"TOW" that's a good one, Marvin....

>
>
>Ah yes, but we only use the gun at around 5-10 PSI.
>
>

Well its true that the NOZZLE pressure on these guns is in that range but...the inlet pressure to create that after the conversion process is in the mid 40 PSI range.

I spent some time looking into this after our conversation at the Nats. And also looked again at the spec sheet for the gun. Effectively, these guns convert the higher inlet pressure air to lower nozzle pressure of 5-12 PSI but with the high volume change in the process--its gas physics I guess. On the inlet guage there is actually a green range around 40-50 PSI.

I confirmed this with some of the autobody guys as well.. Perhaps your matrix clears are easier to atomize and get to lay down. The Omni AU didnt behave really well at all---even thinned up to 200% ---until I got the inlet pressure up in the 'zone"

Note I didn't have any trouble shooting the grey primer--really thinned, nor the Omni base coat --thinned to PPG spec.--at the lower inlet pressure of 10-15 PSI trigger-down. The trouble didnt really show up till I began working with the clear.

Remember too, that the HVLP nozzle pressure of 10-15 Max is an environmental protection driven limit--it is definitely not the way to get the best atomization and finish--most of the old school body guys will tell you that the best finishes come from conventional, gravity fed guns--but the EPA is clamping down on them all because of the overspray and VOC problems associated with high thinner contents required.

Anyway, just my observations and data points. I do like the system, the gun, and your top-notch description. Cant wait to do the next plane now!

This inlet v. nozzle pressure question would be an interesting one to put to your spray and finish expert. Perhaps Nils will chime in here as well.

FWIW

>Well its true that the NOZZLE pressure on these guns is in
>that range but...the inlet pressure to create that after the
>conversion process is in the mid 40 PSI range.

True, I do set the compressor regulator to run 40 PSI into the gun. The regulator is set to an inlet pressure of 10 PSI for shooting clear (Now, you understand that is with the trigger pulled. Pull the trigger and look a the gauge. Shooting clear I am right at 10PSI (basecoat is typically less with a smaller fan). Static, without the trigger pulled appears higher on the gauge (obviously it will show the inlet pressure or close to it).

The gun gauge is always set with the trigger pulled.

I guess I'm at a loss to explain how that gun can be giving you a good finish with only 10PSI set on the handle gauge. The internal workings of the gun provide a (typical) 10:1 pressure reduction to the nozzle.

Anyway, I hit a combination that works for the materials I have been using.

Reference this site for a little background on HVLP from the EPA.

http://www.epa.gov/dfe/pubs/auto/spraygun_success/index.htm

FWIW

>
>My 3 HP Cambell Hausfield single phase 110 volt never
>starves shooting paint. Maybe running a DA or a buffer is
>right on the edge.
>

Guys,

Clearly maintaining a HVLP option drives the purchase of the largest and most powerful compressor practical. This may not be where I want to go.

Can anyone recommend high pressure spray guns, particularly touch up guns, which will work well with compressors in the 5-10 gallon capacity range? I'm not going into the full time professional airplane painting business and would like a "small is beautiful" option if it exists.

Again my thanks for the wealth of good information!

>Clearly maintaining a HVLP option drives the purchase of the
>largest and most powerful compressor practical. This may
>not be where I want to go.

Bill maintains that the HF gun is really a "conventional" gun with a top feed. The "HVLP compliant" standard means that the tranfer rate is above 75% or something like that. That makes almost all top feed guns HVLP compliant.

When you are as typing impaired as I am, you reduce everything to as minimum a volume as possible.
See you at labor day shin-dig.
Bigiron

I'm probably the one guy that had bad luck with the HF HVLP gun. I do use the larger HF gun for primer and it works fine. The smaller touch up gun was OK, I guess, but I'm not likely to abandon my Binks HVLP touch gun for it.

I got a deal on a compressor. It's a big, stand up unit for air tools. 80 gallon tank, 7.5 hp job. A neighbor that does diesel mechanics got it through a distributor he knows...well, you get the idea. 220 volt, so I had to do a bit of wiring in the shop for it, but it sure works. This is one area that it's nice to have some overkill.

HI Andy. I got an Ingersol Rand compressor from myself. I sold tools for MATCO for five years. It is 3 HP and has a 30 gal. tank. Two in line water traps and the regulator is at the outlet side. It is more than enough, but doing mech work with air guns, etc, it was needed. A 20 gal tank is just right for models and airing tires. I have a HVLP gun, but have used it only once and it is for clear only. I use a Badger 175 or 150 dual action brushes for other work. The HVLP gun is not unlike the 400 Badger.
Always buy bigger than you actually need, it's cheaper in the long run and you will always have the air you need. I have one of those small air compressors by Paaschae (what ever) and it is fine for my HO locomotives and box cars, but not for a large PA plane.

Here's a couple compressor items not mentioned, as far as I could tell.

1. True HVLP systems get good atomization at low pressures because the air coming out of HVLP compressors is quite hot, that helps a lot with atomization. Using a conversion gun, you lose this advantage.

2. If your compressor runs alot when you're spraying, you end up with a bigger problem of water in your finish. As the duty cycle runs up, more water stays in the air because it's hot. If it doesn't cycle much, the air cools in the tank, and that is where the water winds up.

Someone mentioned (Zilla?) it's best to put the filter as close to the gun as possible. EXACTLY correct. Even better, buy cheap air hose, put it in a cooler or bucket with ice water, then run it through a water separator, you can see it fill with water! The normal water separators only remove water particles, not vapor. If you have a water problem, try the bucket of ice thing, lots of metal pipes, or a dessicant filter. Expensive, but EFFECTIVE. There are cheap non-reusable inline dessicant filters for people who only have occassional problems. Actually, they can be re-used, that's another post.

3. Oiless compressors generally aren't the way to go. NOISY, as mentioned, and notice all the plastic housing around the pump? It's there because they have a tendency to blow up. BUT, no oil problems...

4. Two stage compressors are great if you have a need for higher pressures, but they put out hot air all the time, up to several hundred degrees during normal operation. Water separation is a must in humid places with these things. I run a 80gal 3HP (true 3HP) two stage pump. It puts out TONS of water here in the humid south. However, it's pressure lubed and has a 100% duty cycle, worth the pain for me, probably not for everyone. Also, it only runs at about 700rpm, is older than me, and will live longer.

5. I think the BEST bang for the buck is one of three compressors.

a. the pancake

b. the Black Max sold at Sam's, will run on 110, but better on 220.

c. Grainger's Speedaire on a 60gal tank. Only about 800 bucks, iron pump. Much better than the IR aluminum pump models sold at home improvement stores.

These are in order of capacity, smallest to largest. Probably 4cfm @ 90lbs, 9cfm @ 90lbs, 9cfm @ 150lbs. Duty cycle for all of them is around 60%. The middle one will run a conversion gun REASONABLY well, the biggest if you're serious. Don't bother with only 4cfm @ 90lbs and a couple gallon tank.

6. The more air storage you have, the more apparent capacity you have. Just make sure you don't over duty cycle the pump filling it all up. Have a pancake, want to run a HVLP conversion gun, fine, get a dozen old propane bottles, manifold them all together, fill them one at a time, giving the pump a rest. When they are all full, go to work, repeat.

I love air compressors, and have 3, and want a HVLP next. Probably have 5 or 6 regulators around my shop and 80 or so feet of 3/4 black iron getting it EVERYWHERE.

Oh, last, don't be afraid of used compressors, fairly easy to tell if its in good shape or not. Rusty tanks are your biggest enemy.

Later,

Good post Tools.

>5. I think the BEST bang for the buck is one of three
>compressors.
>
> a. the pancake
>
> b. the Black Max sold at Sam's, will run on 110, but
>better on 220.
>
> c. Grainger's Speedaire on a 60gal tank. Only about 800
>bucks, iron pump. Much better than the IR aluminum pump
>models sold at home improvement stores.
>
>

Thanks for the excellent insights. Quick questions: 1) How many gallons and what HP rating for a good "pancake", and 2) What are the specifications and price for the "Black Max" (tank size, HP, price)?

Finally, is a touch up gun with a 7 ounce capacity sufficient for most painting, or do you really *need* a quart cup?

Thanks,

Dont know about the pancake question.

7 oz cup is plenty. 6-7 oz will cover a full 540 sq in plane with a mist plus full coat.

Besides, your wrist will thank you for not lugging around a quart plus the gun.

If you go with a regualr gun, you might try one of the conventional mini gravity fed harbor freight guns. I have one of the top-trigger, campbell-hausfield knock-offs from the taiwan tool store--Kitts. I dont really like it much. you're welcome to try it as well as my HVLP system sometime tho. Talk to me this weekend.

Hi,

I'll do some checking on pancake compressors for you.

The Black Max dad has is about a 20 to 30 gallon horizontal tank, has a handle and wheels, runs 15 to 20 amps on 110. We wired it for 220. I think he paid around $300 to $350. It's an aluminum pump, but still a pretty nice unit. Runs fairly fast around 1500 rpm. I think it's a 3450rpm motor all geared down. Most compressors have 3450rmp motors. He does a substantial amount of sandblasting and running air tools (sanders and impact wrenches) and has had no troubles.

Smaller gun is fine, like mentioned, your wrist WILL thank you. A touch up gun works great for me.

Got to get back to work, will let you know what I find out.

>
>I'll do some checking on pancake compressors for you.
>

Here's a simple "for instance" setup. Both Harbor Freight items, just because they are easy to point to:

1) 2 HP 4 gallon pancake compressor, delivers 5.2 SCFM @40 psi, 4.2 SCFM @ 90 psi, oil lubricated, for $139.00 Has an output gauge, not clear if an output regualtor is included, but they are cheap and easy to add.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38898

2)Touch up gun, 7 ounce capacity, 30 psi nominal. Consumes 2.8 CFM @ 30 psi, 4 CFM 50 psi, for $19.99.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=86

Add hose, moisture trap, fittings etc.

Obviously this is not the end all dream system, but I would claim that the compressor would be able to keep up with the demands of the gun, the price is reasonable, and it will still air up tires pretty well too . And I don't have to get new wiring or extra heavy duty circuits installed in my house. This is no joke. The compressors used by the contractor who just put on my new roof kept tripping my circuit breakers!

As for the ice bucket water trap suggestion, I have acutally built something similar to mix gases at ice temperature. Take a cheapo ice chest and use copper refrigeration tubing to make a coil. Establish a drain at the low point of the coil, with a bottle to catch the water. Plumb it all with flare fittings, or refrigerator fittings from the trusty Home Depot. I'll keep this in mind if I have excessive water problems. Have to be careful not to drop too much of the pressure accross the coil, of course. Here in Michigan it is not all that humid, but we shall see.

GREAT suggestions guys, I'm much obliged!

Hey Andrew,

Sounds pretty reasonable and a decent setup. Almost guaranteed it comes with a regulator, but like mentioned, sometims a second one near the gun isn't a bad idea.

Just get it and use it see what you think. IF you have moisture problems, then try the jockey box idea, may not even need it. Beware, stuff from Harbor Freight is really so-so. If it doesn't seem to work just right, find someone who knows this stuff to come over and check it out for you. Their customer service is pretty good, so it's more of a nuisance than anything to get something that works correctly from them. If they have something I want, I simply live with the fact it's not too uncommon to have to return and item once or twice till I get one that works.

If you have a problem, it'll most likely be that the regulator doesn't regulate correctly. Be sure to drain the tank EVERY time you use the compressor. You're supposed to with all compressors, but nobody does, not even me. With such a small tank, I would consider it more necessary, more from a 'keeping water out of the paint' standpoint, than rusting your tank out. That takes years.

If you use airtools and an inline oiler, then keep a separate hose for spraying. Don't bother with a filter/separator unless you go to the jockey box.

Have fun and enjoy the new stuff. It's more of a dream setup than you think. Portable air like that is NICE. You don't need a airbomb, plug it in, air it up, unplug and go. OH OH, you didn't mention amperage of the motor. If it's 15amps, you'll be likely to trip circuit breakers on heavily used circuits. Also, it won't like extension cords very much either. If it EVER starts humming when it should be pumping, UNPLUG ASAP. Too much voltage drop and it'll soon burn up the motor.

Any more questions, be sure to ask, lots of great corporate knowledge. I was happy to find the Zilla link, didn't know that was on here! Thanks Zilla!

Later,

There is one bad problem with your stategy- your wife will probably expect you to keep her tires inflated to the correct pressure.

>There is one bad problem with your stategy- your wife will
>probably expect you to keep her tires inflated to the
>correct pressure.

Well, that's the driver really. She *insists* I buy a compressor and keep the tires up. I might as well get a decent paint sprayer out of it .