Aluminum cutting over water table dangerous?

[Traneman]

OK,What is the real answere if there is one.?

Can we cut aluminum using a water table or not.

I understand hydrogen is the byproduct when cutting aluminum, but in talking with a few others doing this they have had no problems.

Is it just worth the time to drain the water table and play it safe.

Just want to get some more opinions.

Everyone have a great Holiday

[jimcolt]

Many plasma users cut aluminum on a water table. Here is what happens: The by product of cutting aluminum is aluminum oxide.....which sinks in the water in the table. This material absorbs oxygen from the water, leaving hydrogen.....which rises in the water. After cutting aluminum you likely will see some small bubbles of hydrogen rising in the water. The quantity is very small....and the hydrogen simply dilutes in air. The only time it can become and issue is if this hydrogen gets trapped...and builds a large pocket.....such as under a large plate with wrapage that could allow (lighter than air) hydrgen to trap.

As a safety precaution.....do not leave large sheets of material on the table for long periods of time....or raise and lower the water afew times to flush out the hydrogen. Some have actually installed steel pipes in the bottom of the water table with small holes drilled in the pipe.....with compressed air running through the pipe.....this air flow bubbles up through the water and supposedly dilutes any trapped hydrogen.

It usually is not a problem...


Jim Colt Hypertherm

[Plasman256]

Jim Colt is correct. When enough Hydrogen collects in the baffled water tank, then the torch becomes the match, the water the fuse, and BOOM. you have a nice little bomb on your hands. I have personally seen 4 companies blow up their machines due to this. There are a few ways to resolve this dangerous issue. 1: If you cut aluminum on a baffled water table, you should purge the tank several times between each sheet. ( Raise and lower the air ballast in the table several times.)
2: install and airator. (Pipes with holes pointing up, with a central connection to an air line. I personally do not approve of this one, but some people use it.) 3: Keep the water all the way down when you cut. If you do this you will still need to purge the table as in option one above, however you can usually due this every 4 sheets versus every 1. Whatever you do, BE SAFE! If you have a non-baffled water table, there is no danger of collecting the hydrogen in a tank. but if the water is all the way up to the plate, it will collect under the plate and "pop" and flame, sometimes raising the plate off of the slats and crashing the torch. - Plasman

[shelbygrinders]

We cut aluminum daily on our table. I've found that using a small fish tank aerator will help dissipate any if not all existence of hydrogen from your water. I haven't tested this scientifically, but it just makes sense as to how it works. We've yet to explode or harm anything or anyone in several years of cutting aluminum on our table. Hope this helps someone.