Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion What size compressor?

To start with,I know nothing about spray
painting.I bought a gravity feed spray gun
recently at Sam's club.($75.00)I thought I
would try and spray a pump.It came out
looking terible,like orange peel.It may be
my inexpierence,not thinning the paint-
Dupont acrilic enamel or my compressor.I
have an older one that the tank size is
about 14 inches dia. by 28 inches long
with a three quarter H.P. motor.It will
not hold pressure while I.m useing it.
How big a compressor should I have if I'm
only going to paint 3 or 4 pumps and air
up tires.I hate to go to expenseive as I
don't use air tools or anything.
Thanks

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JERRY

well your going to get into it heavy (it'll suck you right in) & eventually you'll need to sand sometimes & that uses lots of air! more than spraying! you'll be out buying an orbital sander & a dual action sander, an air grinder, then you'll see a cheap die grinder, it never ends & goes on forever!

i know a part time painter that bought a 5 horse 40 gallon upright compressor on wheels at Menards or somewhere for around 200 & when he does a job about once a year the ol compressor hangs right in there & keeps right up!

I'm only going to paint 3 or 4 pumps?????
Gee I think I said that about 15 years and over 100 pumps ago.....
Once you do your first pump you will be hooked and then every friend you have will also want 3 or 4 pumps....
Like Tom 2 Tone says go a head and get at LEAST a 5 horse and a 40 - 60 gallon tank because you will not stop at 3 or 4....
Once you use a few air tools for body and paint or even working on the cars, [I would not even start a auto repair with out my air ratchets and impact guns] You will find out how much easier it is with air tools that you will want to do more projects now that you are not working so hard on all of your projects as you were without air tools...
And last but not least if you do even one pump you are hooked!!!! Before you know it you will be looking over every fence around the back of every building and driving for hours looking for gas pumps and old signs, Welcome to the Old Gas Zone....
P.S. I really think one of us should start a Gasaholic's Rehab center, think of the money our wives would spend to get us cleaned up...
Hi my name is Don and I have a problem and I need help!!!!!

[This message has been edited by gaspumpman (edited 10-04-2004).]

I've been using a 5hp-40gal 110v compressor for several years now. I'm happy with it. I don't use it every day or all day long. I do have to stop and give it a break while sand blasting, but it gives me a break too.

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ROD [Mich.]

Pumpman2:

Look at the information that came with your paint gun. It will list the 'CFM' (Cubic Feet per Minute) air requirements of your particular unit. Then make sure that you purchase an air compressor that at least meets this requirement. It's always better to go bigger if you can afford it.

A 5-horsepower compressor with a 40-gallon (minimum) storage tank will probably fit the bill. If you have room for an upright - that's the way to go. Make sure that you get an air regulator unit that also removes moisture. And pick up a small air regulator to attach at the inlet of your paint gun. Set the wall unit to 10 psi above the requirements of your gun and fine-tune the actual pressure at the gun. You can - and will - have a pressure drop over the length of your air hose.

Read and follow all mixing requirements for the type of paint you are using. The store where you bought the paint will have spec sheets available for each and every product they sell - get a copy of everything. Mix your paint according to the manufacturers recommended ratios i.e. 4:2:1 = 4 parts of paint, 2 parts of catalyst to 1 part of reducer (as an example). Pre-marked paint mixing containers are available that have all the ratios printed on the sides.

Be sure to use the recommended 'temperature' of thinner/reducer for the temperature at which you will be shooting paint.

Enamel does have a tendency to 'orange peel'. That's why I stay away from it and use urethane. Just be sure to use all necessary safety equipment. Most of this stuff can kill you if you inhale enough of it over time. Don't take any chances - buy whatever respirator unit is required and wear it from the time you crack open the can until you walk out the door. Including the clean-up phase! Let no one hang out and watch you paint. The fumes are as dangerous to them as they would be to you. I have a 'guest' mask for anyone that wants to hang out.

Tom, Don & Rod are all correct. Once you do one pump yourself, you'll want to do more and once you finally break down and purchase an impact gun - you'll be hooked on air tools!

Hope this helped.

Later . . .

Jim



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http://www.vintage-logos.com

[This message has been edited by T-way (edited 10-05-2004).]

Jerry,

Hows it going? Havent talked to you in a while.

Here is the scoop.
1. You have a tiny garage, a 5 hp. 60 gallon compressor is not necessary for you. A 20-30 gallon two pistion compressor will easily supply your air requirements. I have one that is on wheels that I used for years without problems. It just ran alot. I now have a quite large compressor.

2. "orange peel" can be caused by many things, most likley too much pressure at the gun and improper gun set up.

Get a decent compressor, get some panels in primer and wetsanded. This fall when I come to Racine, I will try to help you with painting so that you can do it on your own.

BUY A GOOD RESPIRATOR!!!!!!!!!!!!


See ya,

Ryan

You must follow the mixing instuctions,as far as reducers and hardners go,or you will have orange peel problems.Practice makes perfect,good luck

You must follow the mixing instuctions,as far as reducers and hardners go,or you will have orange peel problems.Practice makes perfect,good luck

Drink the beer AFTER YOU FINISH PAINTING !!!

the trick to a smooth paint job is to lay the paint on nice and wet and just let it get tacky inbetween coats, practice makes perfect if you put too much paint down it will run...not enough it will orange peel! good luck

One thing to consider about compressor size is that if the unit is too small, it will run all the time while you're using it. It will get hot and stay hot. That will tend to put more water vapor in the compressed air. It will have less chance to cool and condense out before it gets sprayed, unless you have a system more sophisticated than the typical regulator / water trap setup. It is also possible that the heat of constant use could put vaporized oil from the compressor into the air stream. Choosing a compressor that exceeds the CFM rating of your spray gun or tools is the best plan. Horsepower is not an accurate rating. CFM at a certain pressure is.

A long list of factors affect the smoothness of your paint finish. Technique is most important. Once you get that down, take a look at your materials and equipment next. If you use a paint that dries too fast for the temperature, it will not get a chance to lay out smooth. Different clears have a built-in length of time they flow out, no matter how you spray them. Activators and reducers can adjust that somewhat. A slower drying paint just flows out better, but is more vulnerable to dirt and runs.

A big factor is atomization. The old way of thinking was to spray paint as heavy as you could and it would flow out smooth if you stopped just short of running it. The new way is to have a paint gun with very high atomization that breaks the paint into extremely fine droplets. You can then spray with less pressure, less overspray and less total materials. I have found that a good gravity feed paint gun with a 1.3 head gives great results. Your paint motion will be slower than the old way, but the finish will be smoother.

And I have to reinforce the above warnings about wearing respirators. Wear them for sure. Keep them in a zip-lock bag when you're not using them. Keep even the slightest amount of fumes out of your house and away from your family.

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Jim "Oldgas" Potts
Your host and moderator

Well Jerry youv'e got a lot of advice here. Just to add to me last post, I'd say your 3/4 hp 10 gal compressor probably isn't the problem. Doing only a couple panels at a time it should keep up. Most paint problems result from improper mixing, too much air, not enough air, paint too heavy, too light, improper spraying technique, see this goes on and on, but it is usually the guy holding the gun that messed up. The most important thing you can do is ask questions at the paint store. Tell them what your doing and have them make the recomendations. It is not necessary to spend big bucks on paint either. Heck, I've sprayed several pumps with One Shot sign enamel with clear coat and had very good results. Practice is the key. The more you do the more you learn.

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ROD [Mich.]

Thanks for all the advice guys.It really
is appreaciated.The guy that painted my
first pump for me and was going to show
me how to go about it with this next pump
was up north last week cutting down some
trees and fell out of one and broke his
pelvis his back and got some head injuries.
He's a really swell guy and was just about
to retire.When were healthy we better
appreaciate it. Thanks again.

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JERRY