Refill that empty aerosol can

[garyahouse]

Recently, I grabbed an aerosol can of penetrant and pushed the button only to find that it ran out of air pressure long before the penetrant was gone. I threw it away, wasting perhaps 1/4 of the can. Later on I did a google search for refilling aerosol cans with air and came across a couple short videos where guys created a simple method of "refilling an aerosol can with air" by using an old rubber valve stem. Wish I would have known this before I threw out the rest of that can. Needless to say, there is always a danger involved in doing something like this if you don't watch your pressure, so beware. I could provide the links, but not sure if that's allowed on the forum.

Gary

darksider #44

 

[08FJR4ME]

Why wouldn't it be. Just add a note saying try at your own risk or something to that effect. Seeing it was some kind of penetrant I may have just poked a hole in the can and put the rest in a squirt bottle.

Wait a minute, can I post that?

Dave

 

[garyahouse]

Dave,

Why wouldn't it be? That's a good question. Just something I've never done before and thought I'd err to the side of caution.

One describes resizing the rubber air valve to fit the average spray can. This is necessary because the little tube sticking out the top of any aerosol can... must be depressed to put extra air in (or out), as we all know.

Anyway, I thought it was interesting that one of the fellas doing these videos tested some brand new aerosol cans and found the pressure to be between 95 and 125 psi from the factory. I always wondered how much pressure they might contain. He set his pressure regulator for 95 psi and filled it up. The process was so simple and quick, I was amazed. Through the years, I've tossed many a paint can due to low pressure though there was still paint left in it. Thought this was valuable enough to post here.

Gary

 

[Geezer]

A quick google found more than one video showing how it's done. I'm not sure I'd risk recharging a can, but in a pinch I might. I would think that repeated recharging would weaken the can or valve so I would not recharge the same can repeatedly.

You can also buy rechargeable/refillable pneumatic sprayers for under 20 bucks. These are common in auto shops where they buy brake cleaner in bulk.

 

[garyahouse]

Hey Geezer.

I've never actually done this. But it seems easy enough, now that I know HOW... as long as the rubber valve stem is the right length to both be able to depress the stem coming out of the top of the aerosol can... and seal tight against the top of the can at the same time.

I wouldn't be concerned about weakening the can, either it can take the pressure it was designed to take, or it can't. I'd guess that all cans are engineered to be able to take far more pressure than what they actually have when new. Manufacturers hate law suits so they mandate safety margins. I wouldn't be worried about that. I would however, be careful not to fill the can with more than about 90 psi; well below it's normal pressure from the factory.

But needless to say, if I filled a can just once, I'd assume it would be able to spray out all its contents with just the one recharge.

Concerning the valve, I assume you mean the tube coming out the top of the can? I suppose if someone got klutzy, they could indeed booger up that tube. But either it works or it doesn't; and since I would have thrown the can out anyway, I have nothing to lose by trying.

I hear what cher sayin' about the rechargeable sprayers. But I was just talking about how to deal with the 30 plus cans of various things I have setting around the garage. Seemed like a good idea.

I would be concerned however, what regular air might do to the contents of a can of paint. If I'm not mistaken, I believe cans are normally filled with something besides regular air. Who knows. But atleast I'd be able to finish using a can. Storing it long term afterwards might be a different story.

Thanks for the input.

Gary

 

[Geezer]

I agree that aerosol cans are likely to be engineered with a good amount of tolerance, and I have never heard of one failing under normal storage and use, but the metal will fatigue with repeated use. I suspect that the seam is the weakest point. They are not designed to be recharged. The Youtube videos I watched discussed refilling and recharging the cans, implying that they can be used many times. That is what prompted me to mention the rechargeable sprayers that are available.