Compressor recommendations?

[not done it yet]

Oldbanger,

I’m pleased/contented that you have realised that FAD ( Free Air Delivery) is the important, and only true, way of expressing compressor output. Think here, too, that air-tool suppliers only quote FAD - it matters not whether that air requirement is sourced from a 3, 10, 14 or other cfm capacity compressor. Tool manufacturers, of course, quote the lowest FAD for their products and the end-user may not achieve that figure as the tool wears/ages.

Also understanding that a 16A outlet would be the minimum safe size in order to run a 4HP motor is commendable.

The berks (carefullly checked the meaning of that ) who do not accept the reality of known over-hyped marketing practices deserve all they get. Being unaware (and thus conned) is one thing, but knowing and then ignoring the true facts, after being informed of the dodgy marketing practices, is another.

As another example of dodgy marketing, I have a 40A plasma cutter which was originally marketed with a moulded 13A plug fitted and sold as a hobby machine (as well as for light commercial use). The manufacturer had to replace that plug with a 16A connector to comply with the power requirements of the machine at full output.

Yes, mine is run from a 13A three-pin plug at times - but not at full power - because I know that I am not overloading that 13A plug. I don’t ignore safety issues and am fully aware that I need to use a 16A supply if I intend to use it at full power. The average purchaser likely would not have known that it was inappropriate (possibly unsafe) to use the machine at full power.

 

[Burdekin]

Thanks for all the replies, it seems as if I have also been duped by the tricky marketing tactics.
This actually makes things a lot more difficult. I'm currently working out of a double garage with a view to up sizing in the near future to my own unit. My garage will really struggle for the space required by a 300l compressor and also don't want to dick about too much with the electrics for it's supply.
Looks like I may have to buy 2 compressors after all. I was hoping to find something that would be reasonably compact but also powerful enough to cater for the needs of my unit when it's eventually up and running.

Two compressors can take up less foot print. You can hide them away under a bench, stack them on top of each other or build a high level shelf. They're not that heavy and once up out of the way then you hardly need to touch them. Pic of one of mine, it's not that big that you can't get it into some unused space.

 

[JOEPRO]

I think some of the guys posting on here are getting very uptight and making the discussion unpleasant.

Calm yourselves.

My take - buy the biggest compressor you can and that your power supplies etc will supply.

For me I bought a good used like new SIP 200L 3HP compressor and it is great. I use pretty demanding air tools like belt sanders etc and it copes easily.

It is also great for spraying.

I think for any Hobby / single user these are fine.

For sand blasting etc then I'll likely want to double up with another comp the same.

 

[Jack_K]

I have a 2.75hp (maybe 2.5, the label is missing) quality three cylinder compressor which I have used to restore a very rusty car. It does get a workout if I am doing lots of grinding or sanding but it does do the job (it helps to have quality air tools too).

I am adding a second one that I also got cheap which is what you could do, start with one and add another.

Compressors this size are still portable if you need to do work somewhere else like using nail guns or inflating tyres without the obnoxious noise of a direct drive compressor.

 

[JOEPRO]

Yes good point direct drive units are always noisy and quite hard on the ears.

Belt driven compressors are much preferred. (I have both types and use them regular)

 

[Burdekin]

I have a 2.75hp (maybe 2.5, the label is missing) quality three cylinder compressor which I have used to restore a very rusty car. It does get a workout if I am doing lots of grinding or sanding but it does do the job (it helps to have quality air tools too).

I am adding a second one that I also got cheap which is what you could do, start with one and add another.

Compressors this size are still portable if you need to do work somewhere else like using nail guns or inflating tyres without the obnoxious noise of a direct drive compressor.

I started with a direct drive, then got the belt drive and then another cheap direct drive. I'm lucky I could put the direct drives out of the way in another room so the noise wasn't much of a issue. They are noisy and wouldn't like to be in a small room with two going as you work. They're cheap and if on a budget they'll do the job but a belt drive is the way to go if you can afford it.

 

[Jack_K]

I started with a direct drive, then got the belt drive and then another cheap direct drive. I'm lucky I could put the direct drives out of the way in another room so the noise wasn't much of a issue. They are noisy and wouldn't like to be in a small room with two going as you work. They're cheap and if on a budget they'll do the job but a belt drive is the way to go if you can afford it.

At work I have to use a direct dive compressor standing right next to it and I hate it, they are so much louder.

 

[J1nx]

A three kilowatt plug outlet will only support about a 3HP motor (a true 3HP motor will only provide 224kW of power.

Can you explain this please, you say ‘only’ but that seems a lot of power?

 

[Ubique]

It's a typo - it's around 2.2kW for a 3HP motor, but as with most things, 'it depends', on variables to be an accurate rating.
In no particular order
Supply voltage
Volt drop under load of the final circuit
No. of poles in the motor.
Build quality of the motor
Friction losses
Temperature - ambient & motor/compressor block
Etc.
Etc.

 

[brightspark]

a 3hp motor runs full load at about 12 amps but the starting current is about 50 amps they will run on a 13 amp plug most times but sometimes pop the fuse

 

[brightspark]

a plug 13 amp fuse will run on well over its stated current https://www.pat-testing-training.net/articles/fuse-operation-characteristics.php

 

[Keith 66]

Other option if you need a lot of air & limited leccy supply is a compressor with a petrol engine. Some years ago i bought a big old American Industrial Equipment compressor with 3 cylinders W fashion, It had a Kohler command 6 air cooled petrol engine bolted onto it. It had an unloader in the tank to vent air once max pressure is reached, It runs up to 120psi very quickly & then farts off. I used it for fairing boats with the air file & it drove that easily.
Drank a lot of petrol though! It hasnt been used for years, think i need to run a test on the tank before i fire it up again.
Out of interest these AIE compressors were used in WW2 for salvage operations, one oil tanker that had been torpedoed several times but not sunk basically sailed across the atlantic with most of its bottom blown out to a repair yard with a bank of compressors filling the tanks with air continuously. Heaviest hovercraft ever!

 

[Oldbanger]

What air tools are you running and are you really using a "HVLP" gun. HVLP was designed for US legal requirements so is not actually the best to use.

Depending on what tools you are using and you get something other than a HVLP gun a true 2.5-3.0hp belt driven compressor (approx 60-100l tank) will do ok if you aren't using it a lot (too small for professional panel work). Tank size doesn't make much difference for most applications, people think a larger tank gives more air but it just makes the compressor run longer and hotter.

On single phase if you can afford it I would join two together or buy one of the ones which are two compressors on one tank.

CFM/LPM FAD at a specified pressure is of course the best way to measure compressor size but as long as the HP ratings aren't inflated like they do in the USA then HP is the easiest way. Reasonable compressors with the same true motor HP should all output about the same amount of air whereas CFM depends on at what pressure it is measured and many brands will advertise values at different pressures.

I plan on using hvlp gun and air tools like my sander, saw and angle grinder.
The clarke industrial range seem to have pretty good reviews from long term users and I've got a machine mart close by so I'm leaning towards these units. They offer a 200l 3hp unit that I can run from my mains (have to wire up a 30a output) it's less than 1k and they run a 10 % Discount from time to time.
I think that this would be as big as I could manage in my current workspace.
Until now I've used a friends unit for painting and electric power tools, but I'd like to be a bit more self sufficient and not rely on mates good nature.

 

[Richiew]

There's a "VAT free" day on right now. Are you on the mailing list for Machine Mart?

Edit

Selected items only, it seems. Not as good as it used to be.

 

[Oldbanger]

There's a "VAT free" day on right now. Are you on the mailing list for Machine Mart?

Edit

Selected items only, it seems. Not as good as it used to be.

Thanks for the heads up but unfortunately the industrial range of clarke stuff is never part of this offer (so I'm told)
This is the model that I think I'll end up buying unless otherwise advised

 

[James1979]

Thanks for the heads up but unfortunately the industrial range of clarke stuff is never part of this offer (so I'm told)
This is the model that I think I'll end up buying unless otherwise advisedView attachment 397779

Just to throw a spanner in the works have you considered ABAC?

Comparable price if not a bit cheaper but I think better quality

 

[Oldbanger]

Just to throw a spanner in the works have you considered ABAC?

Comparable price if not a bit cheaper but I think better quality

Not really looked into them mate. I'll have a look and see what's available
Are parts easy enough to get if needed+

 

[James1979]

Not really looked into them mate. I'll have a look and see what's available
Are parts easy enough to get if needed+

Yes. Lots of dealers. More so than the Clarke stuff I think.

They’re not exactly industry standard but a lot of small / medium workshops have them.

I think they bought compair.

The pumps are much the same as my compair.

When this dies I’ll go ABAC.

@xtreme engineering sells them I believe

 

[Oldbanger]

Price wise they seem to be on par with the clarke unit. Am I being simple here? I'm sure this one is only 3 phase... Its the closest equivelant I could see to specs on the clarke compressor

 

[James1979]

No you’re not.

Seems they only go to 3HP in 240v as a quick look.