Lidl Hand-Held Compressor + Aluminium Beer Keg

[Blake's 7]

Thanks everyone for your feedback.

For a while now I've been thinking about making my own pressurised sprayer for weed killer so the the PSI would be actually quite low as I do not want to atomise the water\ weed killer mix as it leaves the nozzle. I'm currently using one of these pressure sprayers which hold roughly 10 liters.


I'd like to make something with a greater capacity that would use a compressor of some description to keep a constant pressure in the vessel as I'm spraying. From reading the replies I now realise that the Lidl compressor is not suitable and I also need it to be portable as I want to use the sprayer from the back of my van.

 

[hotponyshoes]

Thanks everyone for your feedback.

For a while now I've been thinking about making my own pressurised sprayer for weed killer so the the PSI would be actually quite low as I do not want to atomise the water\ weed killer mix as it leaves the nozzle. I'm currently using one of these pressure sprayers which hold roughly 10 liters.

View attachment 220366
I'd like to make something with a greater capacity that would use a compressor of some description to keep a constant pressure in the vessel as I'm spraying. From reading the replies I now realise that the Lidl compressor is not suitable and I also need it to be portable as I want to use the sprayer from the back of my van.

Could you not just use the keg to store the liquid then fit a 12v water pump ? Sureflo type thing?

 

[Screwdriver]

Vacuum can only get to a max of 14 psi - atmospheric pressure!
For vacuum forming you won't need a "hard vacuum", you're very unlikely to get better than 10-12 psi without an expensive pump, trying for a hard vacuum gets expensive as a lot of materials (particularly oils and sealants) will start to outgas and leaks are hard to spot - bubbles form inside leaks, not outside! A keg will be fine for vacuum that's achievable at what you can afford

Your empty keg will only pull its volume x vacuum, so if you start with e.g. 10 psi of vacuum, by the time you've pulled half its volume it'll be at a much softer vacuum, so based on a book my late uncle* gave me you'll want to do the initial pull with something like a hoover, close that off (big ball valve?) then hit it with the keg's harderer vacuum for Best Results - or the hoover may do it well enough?

If you're doing larger forms, standard practice in industry is to have an autoclave / oven around the form, could be as simple as a couple or tens of yards of nichrome wire in an insulated box and a PID temperature control (PIDs are a few quid from nice gents in China at the mo, and deliveries don't *appear* to be any slower than usual despite the Plague)

I use a lab-grade low-vacuum pump for bleeding hydraulics / emptying sumps, small vacuum formings like gauge lenses e.g. for my Trav-A-Dial) the vacuum vessel for that is a big glass mayo jar (lots of emptyings!) and it works ok, no clue how hard a vacuum it makes though, enough to have to release vacuum to unscrew the lid!

Dave H. (the other one)

* Uncle John had a business doing... vacuum forming and plastic coating, after demob from the early 50s through to the 70s - the book's "Practical Plastics" and sparked the idea for it, still have it somewhere, I hope!

Food for thought. Thanks.

I hesitated even to say "pull a vacuum" because I understand a lit. vacuum is difficult to achieve and I didn't say "hard vacuum" though I was thinking it!

Interesting what you're saying about what happens if I used a keg full of vacuum to evacuate a plastic forming chamber. Hadn't really thought that through I suppose, makes sense now you say it. In practice such a system would need a much larger volume to work effectively and I bet the costs for that sort of tank go up exponentially. I might scratch that idea then though I will still build a vacuum pump for a degassing chamber so I can play with resin stabilised wood, I do have an actual proper chamber for that. I recall being somewhat baffled by the rating for that thing too. Easy to forget there's already 14psi all around and what that means in reality when you start reducing it.

 

[slim_boy_fat]

@1Billion Amps I made a small tank from a gas cylinder, which I refill using my Lidl compressor. I't's easy to carry it to the car for topping up tyres etc [also as a 'swarf clearer' ].

I'm sure I did a post about it in the "Things I made today" thread.

 

[Matchless]

when I had salvage cars stored on a farm, I was the Norwich Union salvage agent for North London, I had a beer keg, alloy, that we would charge up with 90psi to inflate tyres, I did check at the time and it was rated higher,

 

[Cobbler]

I made this up over 40 years ago, in those days I used to pump it with an ice cream deep freeze compressor. Still use it today on occasions

 

[Rig Pig]

Pictures

That's neat, do you have to run an oil separator on the compressor outlet or is it just couple it up and switch on? I would like to make a quiet pump for my workshop.

 

[Milkybars]

@Rig Pig it's never collected that much, I was concerned that it's easy to overfill the fridge compressor. I just wanted dry-ish air and those separators are not that much on fleabay.

 

[Rig Pig]

@Rig Pig it's never collected that much, I was concerned that it's easy to overfill the fridge compressor. I just wanted dry-ish air and those separators are not that much on fleabay.

I was wondering if you had to put a separator inline between the compressor and the tank to return the oil to the compressor, sounds like it works happily without. Makes life easier!

 

[slim_boy_fat]

I'm sure I did a post about it in the "Things I made today" thread.

Oh, look what I found

 

[hotponyshoes]

Thanks everyone for your feedback.

For a while now I've been thinking about making my own pressurised sprayer for weed killer so the the PSI would be actually quite low as I do not want to atomise the water\ weed killer mix as it leaves the nozzle. I'm currently using one of these pressure sprayers which hold roughly 10 liters.

View attachment 220366
I'd like to make something with a greater capacity that would use a compressor of some description to keep a constant pressure in the vessel as I'm spraying. From reading the replies I now realise that the Lidl compressor is not suitable and I also need it to be portable as I want to use the sprayer from the back of my van.

For what you want, do a search for
beer line cleaning bottle


This is basically a plastic beer keg but you can unscrew the top leaving a nice big hole for filling.
They are chemical resistant (obviously check with what you are using)
They go up to 15l I think.
Keg connector goes on the top and from there all the fittings are common and readily available.
Only downside is you would need a pressure source and regulator but a bottle of pub c02 is cheap.
Everything will have the correct safety valves etc, one way valves, and you could run it upto 50psi.
You could have as many as you wanted if you need more than one ratio or type of mix and they would be quick and easy to swap and the valves will hold pressure in the bottle so you don't waste much gas.
I expect second hand beer kit is cheap at the moment. I know I'm not likely to be using any of mine for the next few months!!
C02 costs work out at about £1 per 50l keg at about 25psi.
You could ditch the gas and feed compressed air instead and the safety valve would still work properly but, as said, I think that little compressor will cook trying to do it for extended periods.

 

[Rig Pig]

Thanks everyone for your feedback.

For a while now I've been thinking about making my own pressurised sprayer for weed killer so the the PSI would be actually quite low as I do not want to atomise the water\ weed killer mix as it leaves the nozzle. I'm currently using one of these pressure sprayers which hold roughly 10 liters.

View attachment 220366
I'd like to make something with a greater capacity that would use a compressor of some description to keep a constant pressure in the vessel as I'm spraying. From reading the replies I now realise that the Lidl compressor is not suitable and I also need it to be portable as I want to use the sprayer from the back of my van.

Wouldn't something like a 12v windscreen washer pump be easier? No pressure tank to worry about, just a switch to turn it on on the lance.

 

[hotponyshoes]

when I had salvage cars stored on a farm, I was the Norwich Union salvage agent for North London, I had a beer keg, alloy, that we would charge up with 90psi to inflate tyres, I did check at the time and it was rated higher,

Some of the home brew kegs designed for carbonation will go 100psi+.
The 'standard' dispense keg is normally 50.
They all have a rating stamped on them somewhere

 

[8ob]

Hi all,

I see from their latest brochure that Lidl will be selling these shortly.

View attachment 220094
I have had an aluminium beer keg in my possession for the last number of years after finding it in a skip full of scrap metal and I'm wondering if it could be made into an air tank with the above compressor attached to it somehow?

Has anyone here attempted something like this already?

Looking forward to your feedback.

Thanks.

With any of these cheap tyre inflaters you need to look at the max run time, a lot of them will melt pumping up anything bigger than a wheelbarrow tyre.

Bob

 

[Blake's 7]

Thanks guys, I read the forums during the day but can't log-in whilst at work to reply unfortunately.

I just spotted this - https://www.mig-welding.co.uk/forum/threads/stuff-you-have-made-today.67127/page-478#post-1532334 - on the "Stuff you have made today" which was posted yesterday by @3000alloy !!!




Back in late February @Mick Annick posted this in the "Stuff....." thread which caught my eye at the time as I was thinking of making something similar for my weed sprayer.

 

[Blake's 7]

This is the keg and the gas bottle is one I got dumped a week ago.



The fittings on top of the keg are brass with an inner piece screwed into a collar sitting on a gasket.



I was able to turn the inner piece clockwise about half an inch, but can see no way to do so anti-clockwise due to the design of the fitting.



Any ideas how I'd get the inner piece removed on it's own?

 

[Screwdriver]

This is the keg and the gas bottle is one I got dumped a week ago.

The fittings on top of the keg are brass with an inner piece screwed into a collar sitting on a gasket.

I was able to turn the inner piece clockwise about half an inch, but can see no way to do so anti-clockwise due to the design of the fitting.

Any ideas how I'd get the inner piece removed on it's own?

They are a fiendishly complicated mechanism, specifically designed to make it difficult to remove without the correct tool. Different barrels will have slightly different methods for achieving the same thing. Most of them have a two way locking bayonet fitting so that they needs to be pushed down to disengage a lock, turned one way to clear the bayonet then unscrewed the opposite direction. Difficult to describe, you can see how they work once they are apart but getting them apart in the first place is awkward without the tool which is not commonly available to the general public.

I cobbled together a puller to allow me to depress the fitting sufficiently to then unscrew a valve remembering an old barrel may have a substantial pressure inside it and will be full of rotten, stinky fluids.

Not for the feint hearted. You can see me edging backwards, waiting for an explosion of vintage horse pi55.

Once off, best bet would be to simply replace it with something else, the one that's fitted is a trap.

 

[earthman]

It strongly recommend that you don't make an air tank with an aluminium beer keg

When it goes wrong you will have a lot of explaining to do and might even incur an unwanted holiday

Ah, but currently you can't go on holiday any where, I think he'll be safe enough then.

 

[Brad93]

Don’t kegs always belong to the brewery?

 

[hotponyshoes]

Not always. You can buy them.
The 'standard' stainless steel ones are about £125.

The traditional real ale ones are about £75-£100
I buy a couple for mobile bars from small breweries as I want to hold stock rather than return it after the weekend. I normally haggle a deal when buying the beer so might pay £25-£50 for one.
If you buy them like a major brewery I bet the discount is massive.