19 replies to this topic

[metro1275]

i have a 2hp compressor is it big enough to spray my car with?
What is the minimum hp needed?
Any help is greatly appreciated

thanks in advance

[ANDY J]

i have a 2hp compressor is it big enough to spray my car with?
What is the minimum hp needed?
Any help is greatly appreciated

thanks in advance

Hi mate i got a 2hp compressor with a 50L tank and 8cfm and mines more than capable of spraying a car even if yours is a 25L tank its still up for the job hope it helps
andy

Edited by ANDY J, 19 October 2006 - 08:52 PM.

[Baldspeed Racing]

What size is the tank? This will be the main thing. You will need a good 25L tank before you can do any serious spraying

[Jammy]

Men, always worried it isn't big enough...

[metro1275]

thanks,
its 2hp 50 litre,
whats the technique?
wait for the tank to refil until spraying or can i spray whilst compressor running?

[midridge2]

a 50ltr tank is not really big enough, you need at least 100ltr.
a small tank runs out of air as you are spraying so the paint reduces as you are spraying. its very bad practice to stop half way through a panel and wait for the pressure to build up again.
it can be done with a small tank but you can only really spray one small panel at a time and it will need a lot of flatting and cutting to get a good finish.





this is my opinion and will differ from others.

[Guess-Works.com]

agree, did my car with a 50l tank and only [u]just[/] big enough, panel at a time. You really need 100 litres to do a car effectively without having to stop for it to recharge 1/2 way through...

The roof is the biggest pain as 50 litres is not enough to do that in one go.

[metro1275]

thanks that is invaluable advise i will hire a biggun or borrow one, Thanks dudes

[jack_marshall]

We use a 200 litre, 2 cylinder compressor and whilst painting a car, one cylinder gave up which meant it was running constantly to feed the gun enough air.

So 50 litre tank really isnt *enough*

100 litre would be orite for a small car, going steady.

[JuaniKart]

well ill have to disagree, i did mine with a 50Ltr tank and yes you do run out of time but i did a few dust coats before hand, pressure didnt go down much really, not enough to notice..

i was told by a friend anything less than 200 was stupid, when he saw my car he was like.. can you do mine?

[midridge2]

good for you juanikart, it just goes to show that even those with 35+ years of car repairs experiance still get it wrong.
we better all sell our big compressors and buy 50ltr ones and still turn out first class jobs like yours.

[ANDY J]

well ill have to disagree, i did mine with a 50Ltr tank and yes you do run out of time but i did a few dust coats before hand, pressure didnt go down much really, not enough to notice..

i was told by a friend anything less than 200 was stupid, when he saw my car he was like.. can you do mine?

yes totally agree as i said before you can use a 2hp with a 50 L tank but my mate remind me the other day when i went to see him that we did his(15 years ago) with a 1.5 hp and a 25 L tank and there was nothing wrong with his finish what so ever, you can always wet sand it after if the finish is not quite right? i will try and find a pic of my old turbo that we did with the same compressor

[Boab]

Or get a higher powered motor like 3 or 4 bhp. I have a Sealy 3bhp V-Twin 50ltr and its fine for airtools. £200 off ebay delivered

[v8mini]

i dont think its the cylinder size or HP that matters, its more the CFM.
if i remember correctly from my previous life as a sprayer, to power a devilbiss JGA gun you would need about 9 CFM (cubic feet of air per minute). obviously various guns and air tools vary for the amount of CFM they require to operate correctly.
i'm sure with 8 CFM you should be ok for most spray gums and tools
no point having a big tank if the compressor cant keep it topped up quick enougth, but i'm sure it would relate to being able to handle more CFM

[midridge2]

its a mixture of things to have a compressor able to do the job.
it has to have a big enough tank to hold the air a big enough motor to replace the air.
a small 25ltr or 50ltr compressor tend not to have a regulator fitted so it will always start off pushing out high pressure but as the air is used it drops, it drops down untill the motor cuts in, the motor then has to replace the air that has gone and the air that is being used.

that means that when you start of spraying and have adjusted your gun to the right configuration as it uses the air in the tank the pressure drops and affects the settings you have made on the gun.

the proof is in the pudding, fill your spray gun up with some thinners and set your compressor away untill it switches its self off then start spraying into the air and watch the fan off thinners comming out of the gun, it will reduce in pressure untill the motor kicks in and it will never be as good as when you started so this would effect the quality of spraying that you are doing, to a untrained eye it might look the mutts nuts but to some one who has seen good spray jobs its only a 2/10.

remember as the pressure drops the paint does not have enought pressure behind it to blow it onto the panels so float around there fore needing more paint and causing a lot of dry overspray.