Buying my first compressor...?

[The Z'eer]

16 amp or 32 amp supplies would still be single phase, you would just need a specific supply with a round blue plug, from the correct breaker in your fuse board

Not really up on electrics sorry to say. Any idea what breaker would be in the board as standard?

 

[addjunkie]

Electrically if your needing a 16 amp supply it would be wired into a spare breaker of 16 amps, like wise for 32 amps.

The tank size just delays running out of air if the compressor isnt man enough to keep up with your air ussage.

You really want a compressor that delivers more than your using so it can stop at high pressure, then restart when required. This also give the compressor half a chance of not running its self to death continuously running.

 

[mr migwire]

get the wolf dakota mate, ive sprayed transit vans with mine among other things, it runs my needle gun, impact gun, paint guns (both siphon and hvlp), its never over heated and is still running sweet as a nut, dont get bogged down with all the numbers etc or you will end up spending mega bucks for a pro machine. there are quite a few members on here who have the wolf compressor and i dont think ive read a bad word from any of them... edited to say it runs from a 13amp standard 3 pin socket under my bench and never trips the breaker......

 

[Crater Creator]

First you need to understand displacement, often manufacturers specify the pump displacement which is wrong but makes the machine look better than it is. You need the machines FAD or free air displacement which can often be around a third less than the pump displacement, the FAD is what the actual tank will give as air which is what you can use, and these differ as certain models may state 3HP with 15 CFM and give around 13/14 CFM as FAD while others may also be advertised as 3 HP with 15 CFM and only give 9/10 CFM as FAD.

Straight away you have a problem as a HVLP spray gun requiring 15 CFM is well above what the tank can give, you do have options, you can get guns which have interchangeable needles and a standard gun may come with a 1.8mm needle and requires 14 CFM of air, meanwhile it may have the options of a 1.4mm needle and a 1.2mm needle which require less air which may be inside your compressor FAD rating.

For spraying and air tools you need the largest capacity of stored air as possible, a 50L cylinder isn't going to deliver, the smallest I would use is 500L or the pump will constantly run and overheat without delivering the air required, you do have options and these are to get extra capacity by buying a scrap compressor, usually with a duff pump or motor and using the receiver, years ago I added a blanking cap to mine and removed it to connect a 1" hydraulic hose to connect to my large receiver and only plugged it in when required to give additional air capacity, and undoing it for normal use.

500 litre for a home workshop? Wow - seems a bit over the top? You can spray paint with much smaller air accumulators than that - 100 litre will do unless you are going to be working it very hard doing whole car spraying etc.
And the needle does not affect the amount of air the gun takes, it only affects the amount of paint flowing to the atomiser. Changing the needle will not change the amount of air a spray gun uses....
The FAD is what the compressor delivers, not the tank.
Just thought I would clear that up in case the OP got confused.

 

[carbon]

Depends on what spray gun you want to use as some hvlp sprayguns use more than others. For example the devilbiss gti pro with an hvlp air cap uses approx 15.9 cfm and with the T110 air cap only needs approx 9.4 cfm according to devilbiss's specifications.

 

[Crater Creator]

Was the conversion easy to do? How many litres does a 47 kg cylinder hold? How long could you spray for with regular 90 litre tank?

Yeah it was a doddle. I went the whole hog and removed the protection "handle", and painted it up nice, made a wall bracket etc, but really all you need to do is fill it with water and empty it (to remove all gas), then remove the valve and fit a BSP adaptor and T it into your compressor outlet with a hose. This is all assuming that you own the cylinder and it's not a rented one as that would obviously be very naughty. Propane cylinders are rated to something like 400psi so plenty more than enough for a home compressor setup.

 

[Masterofnothing]

I would go second hand as you get a lot more bang for your buck just know what to look for same with anything, ask about the history of the machine, servicing, how often its drained of water, last thing you want to do is buy a machine and the vessel is bearly rotted through because the last guys didnt drain it regularly.

Also i wouldnt add a 16 or 32 amp commando socket on to an Existing ring main or radial circuit. Make sure it has its own seperate breaker in the board.

Im also hooking mine up to a spare 100l vessel (first welding project btw!!) To give 225l. This still means the compressor will crank to 10bar and start back up at 8bar but i can use alot cfm before it needs to filll up again

 

[Crater Creator]

Was the conversion easy to do? How many litres does a 47 kg cylinder hold? How long could you spray for with regular 90 litre tank?

I think the 47kg tank is just over 90 litres - so just about doubles the stored volume. And the compressor doesn't have to stop/start so often (but obviously runs for longer when it does start). Still well within the duty cycle though, for the volumes I use.
Also bear in mind that if you're using a tool like a spray gun, you won't generally be holding the trigger down for minute after minute - so you won't be running the air demand at 100%. Bigger is usually better but don't feel you need some costly industrial monster of a machine to do useful work.

 

[carbon]

Sorry should have said the figures in my previous post are at a pressure of 2 bar with the trigger on the spraygun pulled

 

[Mee]

500 litre for a home workshop? Wow - seems a bit over the top? You can spray paint with much smaller air accumulators than that

Not really as I have a little Wolf 3HP as a portable unit, I also have a 15 HP broom Wade and I have the option of using either for large or small jobs, I also have several large barns and three are piped for air. I like the Wolf as I can pick it up and throw it in the back of the 4X4 as it is so light and they also have a decent reputation.

 

[Mee]

Space might be an issue for 500 litres. Circa 100-200, I think I could accommodate that but 500 is a hell of lot, I've only regular domestic garage space. How long could I roughly spray for with a 100 litre tank? With respect to needle size, what happens if I was 1.2 mm? Obviously per second less paint is gonna dispensed, but could this cause problems? Time isn't an issue here.

With a smaller needle you use less air but you get less paint flow, if you are looking to buy a gun or change the needle then check the manufacturer specifications for each needle first as they do vary.

My Devilbiss gun came with a 1.8mm needle as standard and it can hammer paint down, I swapped it for the optional 2mm needle designed for the trade and it blitzes it down, I only use this gun for priming so I can have the primer a little thicker.

 

[carbon]

With a smaller needle you use less air but you get less paint flow,

Sorry but this is incorrect, changing the 'Fluid Tip' and needle just results in different paint flow.
Changing the 'Air Cap' adjusts the amount of air volume used.
See youtube video by Devilbiss regarding Intelligent Atomisation.
Relavant information is from about 1.10 onwards

 

[Crater Creator]

Not really as I have a little Wolf 3HP as a portable unit, I also have a 15 HP broom Wade and I have the option of using either for large or small jobs, I also have several large barns and three are piped for air. I like the Wolf as I can pick it up and throw it in the back of the 4X4 as it is so light and they also have a decent reputation.

Mee, the OP asked for a "first compressor", no more than 300 quid, 240V single phase for DIY use. He says space is an issue as well, so it's unlikely a 500 litre tank is what he needs - or could get for under 300.

 

[vw1]

I am enjoying the thread as I'm in the same situation but have around £800 spend..

 

[RaceDiagnostics]

What kind of paint do you plan to spray, if its 2k you will need to budget the air for an air fed mask on top, which will likely be a lot.

 

[Masterofnothing]

Haha everyone thinks its great when its someone elses money to spend! but in reality if you have a budget we all want what can deliver the most for the lowest price.

Trying to find a machine for a job at a price rather than spending as much as takes to get a machine that is capable of doing the job well is 2 completely different things, you have to know exactly what you job you need it for or you massively over spec to cover all angles... Its not that newer stuff if crap if you want to spend towards the pricier end but buy a budget and anyine guess how long it will last....or spend the budget on used on and get more but you have to know the history of it or you get the same story.

I looked up the spec for my blast cabinet and in real usage terms it takes 10cfm at 7 bar. Which would be 238l/m....which means its a thristy bugger and my comp barely keeps up

If you using the average 45psi spray gun at 3cfm it will drink about 100l/m all depends on how much the tool drinks and at what pressure and how long you plan to use it in a go

 

[mr migwire]

dont need an air fed for 2k, or for base and laquer or celly.... common sense and a decent filter mask will do the job just fine...

MOD - This is discussed here http://www.mig-welding.co.uk/forum/threads/2k-safety-leason-learnt.14051/

 

[The Z'eer]

get the wolf dakota mate, ive sprayed transit vans with mine among other things, it runs my needle gun, impact gun, paint guns (both siphon and hvlp), its never over heated and is still running sweet as a nut, dont get bogged down with all the numbers etc or you will end up spending mega bucks for a pro machine. there are quite a few members on here who have the wolf compressor and i dont think ive read a bad word from any of them... edited to say it runs from a 13amp standard 3 pin socket under my bench and never trips the breaker......

I must admit, I am leaning towards this machine. It does seem to receive a fair amount of praise. Certainly seems up the job according to yourself, may I ask the CFM requirement of you HVLP gun?

 

[The Z'eer]

I think the 47kg tank is just over 90 litres - so just about doubles the stored volume. And the compressor doesn't have to stop/start so often (but obviously runs for longer when it does start). Still well within the duty cycle though, for the volumes I use.
Also bear in mind that if you're using a tool like a spray gun, you won't generally be holding the trigger down for minute after minute - so you won't be running the air demand at 100%. Bigger is usually better but don't feel you need some costly industrial monster of a machine to do useful work.

Well, that's reassuring there If the Wolf unit will work out and the duty cycle is good this may well be the one

 

[mr migwire]

I must admit, I am leaning towards this machine. It does seem to receive a fair amount of praise. Certainly seems up the job according to yourself, may I ask the CFM requirement of you HVLP gun?

couldn't tell you mate, its a devilblis, nabbed it off the brother in law, (he has wayyyyy to many). infact here is a pic of my guns.....