Water is usually used for non ferrous metals, sheet metals, many types of hard plastics and what have you, under 1/4" thick. Adding the abrasive REALLY increases the cutting power. And surprisingly..not all that much abrasive is actually added.
Ive seen 4" thick aluminum on a BIG water jet table. No idea what the max is.
And the kerf is surprisingly small. Though it takes a very special torch and proper machinery to do it.
The pressures are awesome -- over 90,000 psi for the stronger units! holy shit, I didn't know that was even possible. That's proly one expensive effing pump....
Which suggests an upper limit to the psi for flood coolant -- too high and you'd actually dull yer tooling, erode yer material! I'll bet 5,000-10,000 psi is the practical limit for VMC-type coolant, proly closer to 5,000. I think some people here have 3,000 psi coolant -- that's some big-dick machining, yo....
Pressure washers max out at about 3,000 psi, and they indeed can do a lot of damage, house-wise, gouging wood, damaging shingles, like my asshole neighbor does.
Talked to a business several years ago about getting some plate cut. Told me about a 6" marble slab that he cut. Was sent oversize. Sent it back to be recut or get it cut locally? He used his water jet. Said that the only way he knew it was still moving during the cutting was to watch the monitor. It was still cheaper then sending it back east to be recut.
Sarah Lee. They use them for slicing the cakes in your supermarket freezer. Also, insulation materials, fabric, and foil-thin metals, especially aluminum.
The granite under Niagara falls is 250 feet high, and it gets worn away by something like a foot per year.
The Grand Canyon is about a mile deep, and it was cut entirely by water, and the bits of rock and sand the water carried with it.
So the answer is, you can probably cut just about any thickness, and just about any material. The only technical problems to be solved are precision and production rate.
This is sorta related, and might be of interest. Where I work, we do a lot of micro-sand-blasting. Tiny nozzles, and very fine grits (down to baking soda and talcum powder, literally) for very precise deburring of small parts, and very consistent control of surface finishes.
It works well; but it's a PITA. Even with vacuum systems, and enclosures and containement and all the rest, we still deal with the grit getting where we don't want it. And in a precision machine shop, grit of any kind is bad news.
So there's been some talk about a new process: dry ice blasting. The equipment makes dry ice, pulverizes it according to the desired grit parameters, and then uses is (quickly, I'd guess) just the way we now use powders and glass beads. And after the sharp, hard little ice crystals have kamikaze'd into the work, and have done their jobs, they just evaporate, and are wisked away by relatively small and simple vacuum systems that don't need filters or baffles or cleanounts, or anything else like that.
The instant I heard about it, it made sense, and I kicked myself twice because I didn't think of it.
1 foot per year? Heh, I think at that rate, over geologic time, we'd be down to china by now. Mebbe a fraction of an inch per year? Don't forget, the water is falling *into water*, which is essentially coating the granite. The only thing eroding after the pools build up any depth is the flowing water itself, which is proly .001" per year, on solid granite.
But the overall point is legit. Sheeit, wind can erode stuff....
We used dry ice blasting for cleaning built up mold release on our srim forming tools. Worked fantastic.
Wes
-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
The 1ft/year rate is how fast the edge of the falls move up river, not how deep it cuts the channel.
It used to be a lot faster but we reduced the flow, What is the Future of the Falls?
a.. The Falls will continue to erode, however, the rate has been greatly reduced due to flow control and diversion for hydro-power generation. b.. Recession for at least the last 560 years has been estimated at 1-1.5 m/yr. c.. Its current rate of erosion is estimated at 1 foot per year and could possibly be reduced to 1 foot per 10 years. d.. The current rate of recession is unclear; assessing its value remains the responsibility of the International Joint Commission. The International Boundary Waters Treaty stipulates the minimum amount of flow over the falls during daytime, nightime and the tourist season.
I know somebody who worked for a company that did this dry ice blasting for bridge repainting. No blasting grit made clean-up and control of jobsite debris much easier and cheaper.
And NO, it isn't a CO2 global warming issue, because the CO2 used is CO2 extracted from atmospheric CO2 in the first place, usually as a by-product of air liquifaction to generate liquid O2 for steel mills. Global warming CO2 comes from humans burning Carbon stored for millions of years as hydrocarbons and coal, and releasing them into the air as CO2 over a few centuries.
I was at a trade show in Philly in the early 90's and they had one of these things and they used it to cut a chocolate cake in wedges. Slicker than you could ever do with a knife, fast, and it didn't get the cake soggy, either. The water was traveling too fast. Incomprehensible a few years ago, matter-of-fact today. Wowie !
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