Any recommendations for shed air compressor

[Chris TickTockParticipant @christicktock]

Hi Guys,

This is one of those tools sometimes I could do with for blowing out bits of crud from tools etc.

Anyone recommend a small, quiet compressor for occasional use

Chris

[Chris TickTockParticipant @christicktock]

[Ady1Participant @ady1]

The lidl cordless compressor I got is very good, but it was about 40 quid

100 psi, seems to be well made

Got the boss home a couple of weeks ago, I jammed a big screw in the hole in the tyre and pumped it up

Loads up my drain cleaning gun to "thwump!" out the bog and kitchen sink when needed

Could charge up small tank for occasional workshop use or for pressure testing purposes

Just one of 'dem things that's really handy when you need it, can also deflate stuff

a video here

Edited By Ady1 on 14/09/2020 23:02:45

[Speedy Builder5Participant @speedybuilder5]

Soundproofing ! It always gives me a 'jolt' when it cut back in automatically especially if you leave it plugged in during a workshop session !

[Henry BrownParticipant @henrybrown95529]

Following with interest as I have the same needs! My "big" compressor rarely gets fired up as its so noisy and I don't have any space to put it outside the workshop. The Lidl ones are £50 plus and need a battery at about £28 and then a charger too so very expensive, I have a portable twin cylinder tyre compressor that works of 12V so might try to get get a small reservoir for that.

Edited By Henry Brown on 15/09/2020 07:54:05

[JasonBModerator @jasonb]

I have been looking at some of the "quiet" compressors being sold at around the 60-68dB sound range, easy enough to find on the net.. More CFM that the silent types but not defening like my current one which is around 90dB on the label and most likely more than that.

[SillyOldDufferModerator @sillyoldduffer]

Seems to be a gap in the market for quiet compressors! Though it does me OK and was affordable, my dinky little Stanley is on the small side for workshop use, and it makes a terrible racket, worse indoors. The label admits to 97dB and I wear ear-defenders.

Although compressors have many uses can I warn against them as a cleaning aid? Sacking offence in some workshops.

One problem is being hit by a shower of sharp fast swarf. An eyeful of brass shavings is no joke because it can't be removed with a magnet. Has to be washed out in A&E – very unpleasant. (Anyone have a story to tell?)

But the main objection is blasting crud about forces it deep into a machine's delicate crevices. The price paid for a quick shiny exterior is abrasive dirt in important places that are difficult to clean. Swarf inside gibs, under saddles, sprinkled over lead-screws, and blown into motors or bearings is all bad news. And because jet propelled mess can travel some distance, it can cause bother all over the workshop.

Dave

[BazParticipant @baz89810]

Used to have one of the very noisy variety in the workshop and only used it when absolutely necessary, I have recently installed a Bambi and I am delighted with it, I can hardly hear it and it supplies enough air for workshop airline and test running of projects. Only downside is the price.

[HopperParticipant @hopper]

You can quieten a lot down by fitting some kind of baffled or dampened air intake muffler. That is where most of the noise comes from.

[Clive FosterParticipant @clivefoster55965]

If you just want blow air, so 30 – 40 psi is enough, then the baby hydrovane units tankless units sold under the Binks Bullows name to drive continuous flow spray guns are excellent. Haven't been made for many years but they turn up on the auction and advert sites fairly regularly. Typically £40-£60. As far as I know they just don't wear out! Hook a remote switch up to the blow gun so it just runs when blowing. My guess is 60 dB or a bit over.

There is a big difference between 60 dB and 69 dB. My hearing is poor but 60 dB in a smallish shop I'll just about notice, 69 will disturb me.

I used a Compact 106 suitcase style one, like this Fiac unit, **LINK** to run my Bjur Spraymist systems before I found one of the aforementioned Binks Bullows hydrovanes. Even at 57 dB (claimed) I noticed when it kicked in. Insane price new! Mine was a freebee because it wouldn't run up to pressure. Leakdown valve in the control switch wasn't sealing properly. Tiny leak, even with the covers off almost inaudible, but still enough to stop it getting over 70 psi. FAD of 2.5 cfm isn't much so leaks cannot be coped with.

A box with foam or expanded polystyrene on the walls can make a considerable difference to the noise. Surface transmission via the floor is more than you might think. Back in the day I stood my Atlas Copco 16 cfm V twin on a board screwed to a pair of car tyres laid flat on the base of its enclosure which shared same concrete pad as the workshop. Guess it halved noise transmission.

Alternatively seriously consider filling a big, patio heater size, propane tank to 100 psi, shutting off the inlet valve so no leak back through the compressor and using that for blowdown air. Probably a day or mores worth at 30 psi, or less.

The tiny open style suitcase units like this **LINK** look as if you could hang them on the wall to save space. Don't be tempted. The noice is incredible!

None of the affordable battery units are up to the job. Design life seems to be about 500 mini tyres full on the better ones and 500 wheelbarrow tyres full on the bargains. Compressors made as aftermarket units for Range Rover and similar electric air suspension systems are much more durable but design continous run time is only 5 or 10 minutes. Enough to fill the tank. Dangerously high pressures involved. My P38 runs at 140 psi. Compressor is rated to 200! Quiet tho'. In their official box you probably could hang one on the wall using decent rubber mounts!

Clive

[Henry BrownParticipant @henrybrown95529]

Posted by SillyOldDuffer on 15/09/2020 08:50:55:

Although compressors have many uses can I warn against them as a cleaning aid? Sacking offence in some workshops.

Pretty much the same where I did my apprenticeship, a severe bo**ocking at the very least, as was getting an old RE bearing and wizzing it up as fast as it would go with the airline and then dropping it on the floor and watching the sparks…

Jason, after I posted I had a quick look around the internet and see there is a Hyundi (8l 7bar 100psi) jobbie that would fit under my bench for just over £100, may have to look further into that type.

[Clive FosterParticipant @clivefoster55965]

Henry

If I've found the correct one that Hyundia unit is basically two diaphragm style compressor heads, of the type often used for airbrushes, on one motor.

Judging by the single head one I used many years ago that 60 dB claimed sound level is optimistic, especially in a workshop. Maybe at 6 ft in the open air. Expect to need a box in the shop.

In general that style of compressor struggles at higher pressures. Delivery usually falls off rapidly once you get above 40 psi or so. Understandably because the effective stroke is very small and the relatively large flexing diaphragm pump mechanism inevitably leaves little nooks and crannies for air to collect in rather than being pushed right up to the business end.

Small high pressure piston compressors, most especially those used in EAS systems, have relatively long strokes, small bores and only a few thou clearance at top dead centre. Little more than enough to cover manufacturing tolerances. But delivery at lower pressures for a given power is much less.

As ever its horses for courses.

Clive

Edited By Clive Foster on 15/09/2020 11:12:26

[JasonBModerator @jasonb]

This was the type of thing I was thinking of, not as quiet as the Bambi type but a big improvement over what I have at the moment. Would use it for a fog buster on the CNC and the odd air tool too. You can get them with a 50lts tank for about £200., single motor with 15-25lts quite a bit less.

If he can still be heard talking then thats OK with me.

[Howard LewisParticipant @howardlewis46836]

1 ) Don't use compressed air to clean machines. Previous posts warn of the possible dire consequences.

2 ) Direct drive compressors are noisy. belt drive are quieter, probably because they rotate more slowly.

Diaphragm compressors are the quietest, but may not be as efficient – Discuss

As might be expected, the larger; the noisier.

The sound level from a noisy compressor can be reduced, allowing ventilation for induction and cooling, by lining it 's enclosure with egg boxes. This is a cheap way of producing an anechoic chamber, where the surfaces partly absorb, and do not efficiently reflect, the sound impinging on them.

Otherwise get a set of good ear defenders!

Howard

[Chris TickTockParticipant @christicktock]

Your posts have been a great help…thank you.

What I personally have taken on board from the posts or implications from the posts is:

1: Where safety goggles when using

2: For my requirements the Bambi seems appropriate, I will buy as I find one.

Regards to all

Chris

[Howard LewisParticipant @howardlewis46836]

Based on my experience, the Bambi is not suitable for continuous running. The one for the church door seized relatively soon, being left permanently connected to the power supply and so cycling frequently, throughout 24 hour periods, because of minute leakages within the system.. The replacement, timed to be on line only at certain peak times has lasted FAR longer.

It did fail by breaking the retaining bolt for a welsh washer, but we found a method of repair which has outlasted the OE fastener.

Howard

[BazyleParticipant @bazyle]

Any suggestilns for a minimum set-up that can run a grit blast cabinet? Not one for derusting the Titanic just something as an alternative to wire brush on bits of old tools with crevices the wire brush can't get into.

[Martin KyteParticipant @martinkyte99762]

I have an ex Lab Jun-Air which is about as noisy as a freezer compressor for my usual reason that it was free. It's one of the larger ones (actually ex electron microscope air supply). It seems that the tiny ones are used by dentists as well as Labs and do appear on eBay. They are however quite expensive. From new I believe they are virtually oil free (air wise). When the o rings wear they degrade somewhat so I'm told. Very nice if you can pick one up at a reasonable price.

regards Martin

[VicParticipant @vic]

Posted by Howard Lewis on 15/09/2020 14:50:18:

1 ) Don't use compressed air to clean machines. Previous posts warn of the possible dire consequences.

Howard

Agreed. It was frowned upon where I used to work. Lots of (mostly American) dummies doing it on YouTube though. It’s very rare I need to blow air at anything but if I do, I connect the hose on my shop vac to the output side and use a reducer which works quite well.

[Henry BrownParticipant @henrybrown95529]

Thanks for that helpful information Clive, it was one of the first "named" options I came across, as ever I'll do some research before I spend my hard earned pension!

[Chris TickTockParticipant @christicktock]

It appears the use of compressed air in a workshop has a divided following. If we all agreed I would worry.

Certainly blowing metal into an operatives face is stupid. But others are arguing it's paranoia not to use air to clean a machine. My guess is there are viable uses and stupid uses. Just use common sense is the stance I am most comfortable with. I note Sandvik suggest cleaning insert seats with air….there must be many uses, but wear goggles.

Chris

[BazParticipant @baz89810]

Posted by Howard Lewis on 15/09/2020 16:39:27:

Based on my experience, the Bambi is not suitable for continuous running. The one for the church door seized relatively soon, being left permanently connected to the power supply and so cycling frequently, throughout 24 hour periods, because of minute leakages within the system.. The replacement, timed to be on line only at certain peak times has lasted FAR longer.

It did fail by breaking the retaining bolt for a welsh washer, but we found a method of repair which has outlasted the OE fastener.

Howard

My Bambi came from a dentists where it was running pretty well continuously, when I got it the tank was about half full of water, don’t know how often it was drained down but certainly not often enough. Quick oil change and a hydraulic test on the tank just to make sure and job done. Got it on a time switch so it only runs during working hours so it starts about 9:00am and goes off about 6:00 pm if I don’t use it during the day it will cut in a couple of times due to leaks, with normal workshop use it will operate perhaps four times a day, I would imagine that if they are used by dentists they must be capable of fairly hard work.

[Martin KyteParticipant @martinkyte99762]

There ws a 'project' years ago in I think MEW for the construction of a compressed air 'puffer' shaped rather like a large penwith a little button at the end if I remember. It was specifically designed with an orifice which gave gentle puffs to clear things like blind holes of swarf after tapping and such like. Maybe someone will post a reference. It's the high pressure air that does the damage quite capable of blowing particles through the skin. Just enough is all you need and it's safe.

regards Martin

[VicParticipant @vic]

Using compressed air to clean machines of swarf and chips can force them into places they’d never normally go. Not much point in having wipers and seals etc on your machines if you’re going to do your best to circumvent them using compressed air. Cleaning up the workshop is another issue.

I have a couple of 1” paint brushes next to my lathe and mill for sweeping swarf away until the shop vac gets turned on.

[VicParticipant @vic]

The HSE say this in their safety booklet.

104 Blow guns

Blow guns consisting simply of a reduced orifice in direct line with the supply hose can be extremely dangerous, unless preceeded by a pre-set tamper- proof pressure regulator set at a reduced pressure from the normal 80 psi airline supply. Models are available commercially which incorporate an air curtain designed to provide a protective shroud around the nozzle. Although not completely safe, these designs significantly reduce the risk of eye injury and the dangers from close skin contact. If designed correctly such nozzles can often help to prevent the operator from being subjected to excessive noise. Because air is vented directly into the atmosphere, clean dry air is essential and lubricators should not be used. Blow guns can exhaust significant quantities of air and place extra loading on the compressor system. In view of this and the attendant risk arising from use of blow guns, their use should be considered carefully with a view to using alternative means for cleaning down machinery or components.

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