Compressed Air / Air Duster
 

Hi, bought some of these recently in a Poundland near me.

http://www.poundland.co.uk/air-duster

Elsewhere, similar are far more costly.

They were hidden on the bottom shelf, under the USB gizmos for Laptops and Tablets etc.

However have since seen in other (Pound) stores. I suspect customers do not realise what they are, because they are displayed with only the top visible.

Regards - Mike

Re: Compressed Air / Air Duster
 

Ah... yes. I've a couple of these.

Very useful, and a good price but be aware these are I think butane based and not like true 'air dusters' of old which I think used HCFC134A (air con refrigerant). Do NOT use these on any precision optics such as CD objective lenses and cameras etc as the chemical makeup can damage/fog any plastic coating. If you invert the can, they should make a good substitute for freezer.

Re: Compressed Air / Air Duster
 

Hi Mooly, I think you are correct.

However on the can are instructions (some surprised me) e.g. advising not to shake and blow off any liquid first.

But at a 10th of the price in certain places elsewhere, I think a bargain.

Some tasks I had needing such have now become affordable.

Regards - Mike

Re: Compressed Air / Air Duster
 

That's right, if you shake it and squirt you will see a visible trail of 'vapour' come from the nozzle. That will be freezing cold and could immediately damage the finish on anything it comes into contact with.

Use with caution and its fine. Hold the can steady. Give it a squirt first to clear any liquid, and don't get to close to whatever you are cleaning, at least if its something delicate.

Re: Compressed Air / Air Duster
 

When the can is COMPLETELY empty...

1) Cut out the bottom and leave the rolled rim.
2) Fit a 'bolt-in tyre valve' into the side of the can approximately 30mm up from the bottom. Make sure it is properly tightened to form a seal.
3) Nip an inch off the end of the feeder tube inside.
4) Roughen the inside of the can at the bottom end near the rolled edge (very carefully - it will be sharp). Run the Emery cloth around the rolled edge only so that the scratches all run in that direction.
5) Roughen the edge (slightly) of a '50mm plastic end cap'. Run the Emery cloth around the edge only so that the scratches all run in that direction.
6) Glue the end cap into the bottom of the can with strong epoxy. It's a very snug fit.

Voila - when the glue has fully hardened you can refill your air duster using a bike pump. Do so in a dry room so as not to fill the can with humid air.

You'll never need to buy air again! :)

EDIT: the image shows the snug fit of the end cap but you would, of course, glue it into the can the other way round so that it sits flush with the bottom of the can.

CAUTION: over-filling may blow the end cap out of the can so use a very good, well mixed epoxy and leave to harden fully for several days prior to use. And don't go crazy with the bike pump!

Re: Compressed Air / Air Duster
 

A word of warning seems in place. Store bought cans of "air duster" contain anything but. Roughly 3 types can be distinguished (2 of which were already named above).

- flamable (mix of propane and butane - beware: some brands also contain 40% R134a)
- non flamable (1,1,1,2-Tetrafluoroethane, R134a which is a greenhouse gas 1300 times (GWP=1300) as bad as carbondioxide - meaning you can drive to the south of Spain and back instead of emptying a can of this stuff for the same effect on the environment)
- non flamable eco-friendly (1,3,3,3-Tetrafluoropropene, HFO-1234ze which only has a GWP of 6 but is quite expensive and might be corrosive especially when exposed to fire)

Finally, when filling your old can with real air, please mind that it will only take 4 bar of pressure or so. It won't last long but refilling is free and environmentally friendly at least.

Re: Compressed Air / Air Duster
 

Interesting info.

I made a refillable one from an empty Servisol Super 10 can and you're right; it doesn't last long, but I found it to be adequate for blowing out headphone sockets, PC fans, etc., which is all I really need one for.

I loaned it to an acquaintance and he was impressed. Very impressed, I suppose, because I never got it back and he has since moved! I recently bought one of the Poundland cans mentioned and when it's empty I will make a new one.