What compressor for painting real cars

Southwell · #1 29-04-2011

What would be a decent (cheap) compressor for painting things like bumpers, etc. Not after one to paint an entire car, just learn painting smaller items like bumpers, mirrors and things.
Would 13cfm be a minimum?

Cheers

bigred5765 · #2 29-04-2011

you need 8cfm at a bare minimum.

mdb_75 · #3 29-04-2011

If you're only spraying one or two small parts at a time then you don't need a very high cfm if you have a large tank to hold the air. It depends on what gun you use too. As Bigred said 8cfm is a good to start.

Southwell · #4 29-04-2011

Cheers guys, would a kit like this be OK: http://cgi.ebay.co.uk/Wolf-Sioux-25L...item4159048e73

Or should i really be looking at a 50l tank with a different paint gun? I know nothing about it, so will be learning as i go!

I think the biggest thing i would be spraying is a bonnet.

Cheers

bigred5765 · #5 29-04-2011

and treat yourself to a nice quality gravity feed gun(devilbiss or iwata)dear but so so worth it,
and a compressor clicky

Southwell · #6 29-04-2011

Thanks Carl, thats really helpful.

eyeayen · #7 29-04-2011

Spray guns should have info with them, you need to look at what "CFM" they require, this is Cubic Feet per Minute, your compressor needs to be able to deal with what the gun needs. If you're using 2 pack paints you should ideally have an airfed mask which will also have a CFM rating, however if it's only small parts at first you can use a normal mask with twin filters on it, the place you buy your paint from should be able to supply you with something that will help you breath okay. 2 Pack is incredibly nasty stuff and not to be messed with.

I'd get the best compressor and gun you can afford, even a 2nd hand compressor that has been reconditioned and serviced is probably better than a cheap one as the cheap one just won't last, false economy and all that.

Southwell · #8 30-04-2011

Quote:

Originally Posted by eyeayen

Spray guns should have info with them, you need to look at what "CFM" they require, this is Cubic Feet per Minute, your compressor needs to be able to deal with what the gun needs. If you're using 2 pack paints you should ideally have an airfed mask which will also have a CFM rating, however if it's only small parts at first you can use a normal mask with twin filters on it, the place you buy your paint from should be able to supply you with something that will help you breath okay. 2 Pack is incredibly nasty stuff and not to be messed with.

I'd get the best compressor and gun you can afford, even a 2nd hand compressor that has been reconditioned and serviced is probably better than a cheap one as the cheap one just won't last, false economy and all that.

Cheers for that. I doubt ill be using 2 pack at all, if i needed to, i wouldn't be doing it myself!
Is it better to have a compressor that does say 12cfm, even if the gun only specified 7?

Thanks

phil c · #9 30-04-2011

The higher the tank and higher cfm rating the better, that means the compressor does less work , at work we have three compressors all with 250 litre tanks and a 13 cfm rating , and it's suprising how often the compressors kick in and out with fairly light use , ie air ratchets , windy guns ect

Southwell · #10 30-04-2011

Would something like this be adequate? http://cgi.ebay.co.uk/Wolf-Sioux-50L...item5642ab7913

Im going to start with repairs on the other halfs car, so i have to opportunity to re-do work if it went wrong, which i expect to begin with.
I take it painting in a garage or such, i would need to plastic off the area to stop dust and rubbish getting onto the fresh paint.
Im not looking to do outside work, just be able to respray bits on my own cars should they get damaged, like scraping a wall, which the mrs did! I wouldn't want to do this work on my decent car, just older ones, unless i could do a decent job.

Southwell · #11 30-04-2011

Actually, this one looks good! http://www.ukhs.tv/Workshop/Air-Comp...SIVE-3HP-Motor

Would i run into issues with power though?

GRIFF55 · #12 30-04-2011

Get yourself a nice second hand devilbliss gti gravity fed gun off the bay, i have used them for years and they are bombproof. (get a cheapo for high build priming tho

)
I've go a 16cfm taskmaster compressor with a huge tank and that can quite happily do a small car and work tools.

hvlp gun is what you need too (high volume low pressure). the gti is one

phil c · #13 30-04-2011

It looks ok , but will run out of air very quickly, it realy needs a bigger air tank , when the air runs close to empty in the tank the paint will dribble out of the spray gun rather than a fine mist, as long as you wait for the air to build up and the compressor kick out you should be ok . Also remember to drain the water in the tank after every use , or it will go in the paint gun and destroy the paint finish

eyeayen · #14 01-05-2011

Just to sort or what Phil C has said above, it's not so much you'll get the air down to zero and the paint dribbling out you'll have the compressor running almost constant as it tries to keep up with the air required, and if that happens it won't have a long life

Ideally as I mentioned before you need a compressor that is more than your gun, you don't want to be mid coat and have to stop while it fills up and then get a dry edge as you've stopped half way through. So if you're gun is 7cfm and you can get a 12cfm comp then yes that's much better.

2 Pack is the best sort of paint to use, as long as you're careful with it and understand how dangerous it is then you'll be fine. I don't know what else you're going to use. Celly is fine but I'm not sure you'll get the colours, water based it horrible in the respect of you have a black car, when you mix it the paint looks dark green, when you spray it on the paint looks dark blue, once it's dried it's eventually black, then you still need to clear it with 2K lacquer.

CBRDEAN0 · #15 01-05-2011

Just take note that MOST compressors are quoted in PISTON DISPLACEMENT and not true air delivery FAD.

In order to size the compressor and spray gun correctly you need the numbers in FAD ( Free Air Delivered )

Typically a 14cfm 3hp compressor will only deliver 9cfm FAD so it will only run a 9cfm spray gun.

eyeayen · #16 01-05-2011

You learn something everyday ! So, do any companies actually quote that or are they all just luring us into a false sense of security, which to be honest now I've found that out makes a lot more sense why my old hydrovane struggled like it did

CBRDEAN0 · #17 01-05-2011

Quote:

Originally Posted by eyeayen

You learn something everyday ! So, do any companies actually quote that or are they all just luring us into a false sense of security, which to be honest now I've found that out makes a lot more sense why my old hydrovane struggled like it did

I have been working in compressors and with pneumatic tools for 15 years now and it has always been the same.

The piston displacement makes the compressor look bigger than it actually is. ( but no compressor is ever 100% efficient !!!! )

If you dig a little deeper on the manufacturers specs you will find the FAD output of the unit.

EDIT - the reality is that you will only see a maximum of around 9cfm FAD from a single phase 240v compressor.

If you want more air you have a couple of choises :

1. A three phase compressor

2. Piggyback receivers together to get a bigger storage volume - then pump them up to a higher pressure and use a regulator to supply the air to the spray gun. This way you can extend the storage volume by using pressure differential.

Southwell · #18 01-05-2011

Thanks guys, some excellent info help, appreciate it.

Dyna · #19 01-05-2011

As has been said, one of the problems youll have is the paint your going to be able use at home, not so much the equipment ...

They have tightened up on the supply of most types of automotive paints to the man-in-the-street in the last few years.

The main paints...

Celulose - very hard to get these days from factors in specific tints, i order direct from manufacturer for my business, and they do not supply in less than 2.5l tins. Your also limited to less tinters than a few years ago, which means unless you are very good at mixing by eye you might run into colour match problems. Its also 2x as expensive as it was when he law changed 4 years ago and banned its general use... It also dries relatively matte, it dosent have that high-gloss 2-pack shine which most cars from the 80's onwards were painted in.

Its very easy to use & spray, but hard to get a nice, long lasting finish with. You think you have a nice finish, it drys back after a few weeks and can look 'orrible.... And its relatively brittle when its dry... Perfect on pre-80s cars though !

2-pack varients - up until recently, industry standard. You can still get the 'old' 2-pack in most mixes from old stock even now. The new 2-packs are high solids with a lower iso content. We use these, good tinter range, relatively easy to use, good straight from gun finish and lasts well. You dont have to be quite as anal with prep with these as you would with celly. I wouldnt reccomend it without an air-fed mask though. Its still nasty stuff.

Water-based - forget it for spraying at home. Really. Even then you'd still use a 2-pack primer and laquer....

1-pack Acrylics or Acrylic Enamels - most rattle cans are this now, and would be what you would be able to use at home. its somewhere in the middle of celly & 2-pack for ease of use & finish. Good range of tints, good availability. You get this from your local factors.

There are numerous other paint types & systems and developing all the time, but these are the one's youve heard about or would encounter most of the time. You might run into problems buying it though outside of rattle cans, unless you have a friend in the trade to help out there ?

Equipement wise, Griffs Devilbiss GTI is a good choice for touch-ups. We still use the GTI's predecessors - the MP & MPS as our main guns ( if anyone has either of these going spare, ill buy them off you.. ! ). Great for touch-ups. Ive spent 20+ years collecting different guns for different jobs & paint systems. Long term, quality counts.

Compressor, if your going to be doing basic car repair work as well, air tools are the best ! But you'll need a large reservoir otherwise it will be firing up every 15-20 seconds.... think 150 litres minimum. If you buy a 50 litre compressor, forget about using it for anything other than touching up paintwork, but that may be fine for your requirments

Air supply to gun has been well covered above, so no need for me to expand on it.

One important point to mention, is that most compressors over 100 litres require more power to run on than a household plug socket can supply. Last thing you want is to buy a nice high-cap compressor than you have to install a 32amp direct supply in your garage... and of course most quality high-capacity compressors are 3-phase, which would be more expense getting that wired in ! Check the power requirements before you buy anything...

Whatever you do, whatever you buy, the golden rule is that paintwork is all about prepwork ! Get that right, and you will have a good finish even with cheaper equipment.

Sorry for the long post, had time to kill on a long sunday night...

GRIFF55 · #20 01-05-2011

if its only for touch ups, get the mini gti

As for paint and product supplies, i find autopaint st helens a very good firm and they also have some good deals on at times