Home garage compressor.

[Biddlecombe]

I am looking to buy a compressor for personal use, a bit of spraying, a few small tools, etc. Without wishing for anybody to compromise interests may I seek guidance of recommended size, cfm, power etc etc. Its been 28 years since I used one in my engineering business so am out of touch. TIA. Peter.

[bob46320]

Small tools / spray guns don't take a lot of air, however if you want to do a bit of sand blasting and a lot of us would like to do that but don't have enough air. So, decide now, sand blasting yes or no. If No, and you only want to spray small areas - car door, wing etc you will find a 24litre OK. SCFREWFIX do one for just under 90 quid. For just a bit more, you get a 5 item accesory kit thrown in. For me, I don't like the coiled air hose and prefer just a length of plain hose with quick connectors.
However, if your pocket allows - go BIG. Go BIG and buy once - lasts a lifetime.
BobH

[Andy Bennett]

Aldi and Lidl regularly sell small compressors for under £100. However, they do run out of puff if you need to run them for a while (more than a minute or so). These are generally 50l capacity and low cfm rates, but I think they have started to sell higher capacity 24l versions with 9cfm air displacement so much better

I opted to go for a smaller (for space reasons) 24l unit but then for a high performance motor, so went for Draper Stormforce 3HP 24L, which was £200. However, it delivered the higher free air delivery rate I needed for my plasma cutter, of 8cfm (air displacement 15 cfm). It has never run out of puff despite some long runs with the plasma cutter.

I have been very pleased with it.

If spraying I would suggest higher capacity, if just running tools where it doesn't matter if they slow down if run for a while then the Aldi would run fine.

All IMHO


Andy

[Jamie]

I have been doing a lot of brazing with compressed air and bought a "silent" compressor so that I could run it at night without annoying the neighbours. I bought a 24 litre Orazio compressor from Amazon for about £100.00. They do larger models too. I have not sprayed with it yet, but it is genuinely very quiet. You can hold a conversation at normal level while stood next to the running compressor.

Jamie.

[Dennis Nicholas]

Things to consider.
Compressor displacement in cubic feet per minute (cfm) is not the same as FAD - free air delivery  (in cfm) which is the air you actually get out of the machine. Typically FAD is about two thirds of the compressor displacement.
Sand blasting usually needs around 12 cfm FAD.  Unfortunately a lot of sellers  only quote the compressor displacement and not the FAD which is lower. 
The storage tank will determine how long you can use the air for before the compressor cuts in again after it has reached the pressure you set it to run to (90ish psi for blasting).  The cut-on pressure is lower than the cut-off pressure.

For happy blasting you need to get at least 90ish psi and around 12 cfm FAD. The reservoir tank would be as large as possible. My one is 210 lit.

Then there is the electric motor consideration.  My motor is 4HP 3.0KW 18.2 amps 230 volts (asynchronous) This is run off a standard household supply taken out to a 30 amp circuit breaker.  (remember a higher current is taken as the motor starts) as used for your cooker outlet.  There should be an automatic pressure cut-off and cut-on valve/switch fitted.  The motor really aught to have a reset push button (motor overheat cut out).
A good make of air pump is a CHINOOK.
My set up will run sand blasting at 100psi (at the tank) all day with the motor cutting on and off as the tank pressure dictates.....will cut out even while blast gun is blasting.

Consider this.......my one was obtained FREE from a good friend who does professional accident repair work including spraying (with a heated purpose built cooking shop).  Since he had taken on an apprentice he had to have the compressor tested and certificated (annually?) and it was cheaper to buy a new compressor than get it certificated!!!!! so would I like to take it away for him!!  His is switched on all day.
Take the tank outlet to a filter/pressure control valve so you can vary the output pressure from low (15/30 psi for spraying and small tools) to 100psi for blasting (mine has tank max working 12 BAR (170 psi) (tested to 18 BAR).

So maybe ask around at small garages/spray shops.

It is worth getting one that you can get spares for.....check with the seller.  I have had to get one new motor cut out switch (badly mounted contacts in switch allowed loose contacts and sparking so burn out) and have had to renew the seals in the pressure valve that is used to outlet pressure to the pressure on/off switch......cheap parts that allowed easy repair to keep the machine in use (pressure valve opened up for cleaning and spring loaded seal went ping and disappeared never to be seen again in-spite of emptying out the area!! Those thieving pixies again.)  If you can't get the bits you may have to ditch the whole machine.

Dennis

[Reckless Rat]

I have a 50 litre compressor that I bought during a sale at our local DIY outlet. It's ok for most things but runs out of puff with the windy gun or spraying. Best with a 100 litre tank and a twin cylinder compressor. They aren't that much more exoensive.

[Howard Wright]

Hi Peter

I wouldn't be tempted by a "deal" with hose and accessories included. I bought a new accessory pack from a well known auction site after I had bought my 50 litre compressor second hand. The hose was very cheap and nasty and the spray gun fell to bits on its first use.

I called in on my local builders merchant / garden machine shop and they supplied me with a long rubber type hose some excellent tools and quick change sockets.  They also advised the use of PTFE tape on all screwed connections.

I endorse all the comments on the thread about air rates.  I have an Aldi steel cutter that works... but only for a few seconds at a time before the air runs out. 

Finally if you are spraying it is worth getting one or more water traps.  I have one on the compressor and one on the gun. I was very surprised how much condensation and water forms in the bowls.

Good luck

Howard

[Ian M]

I'd recommend taking a look at Machine Mart and evaluating the "Boxer" 3hp belt driven model with 100L receiver, which is right at the top end of their DIY and semi-professional range. Excellent reviews! Once you get into the professional range, special arrangements for power are required, plus most are not intended for portability.

[Biddlecombe]

So I asked this chap who has a business manufacturing tablets and packing them if he knew anybody with a compressor tucked away and guess what? Yes he said I have got one up in the storage I'll look it out for you tomorrow. Thanks so much for the tip. Watch this space!!!

[Dennis Nicholas]

 plus most are not intended for portability.

Thats why I have 2 long extension hoses with quick release terminals......to reach about 80 feet to get to pump up tyres in other barn (ps. the imperial air doesn't realise it is traveling in metric hose)   

Dennis