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Old 04-27-2015, 08:50 AM   #17
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Join Date: Jan 2013
Location: Leonardtown, MD
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Re: Repairing Sandblast Damage

Not disputing your results or the method. But comparatively, a water jet uses a concentrated stream of water mixed with an abrasive, and it cuts right through a panel. Did the water not cool it enough?

What I'm saying is that excessive applied pressure and excessive size of media combined are what cause the peening action, resulting in the stretch. Yes, given enough of this it will eventually cause the temperature of the panel to increase. But the temperature does not cause the stretch, it is a side effect of the peening action. Stretch has long occurred before the temperature rises. So any claim that it can't stretch because water keeps it cools is a bit misleading as to the actual cause of the stretch in typical media it crafty wording or advertising hype, but sheet metal panels are media blasted every day without damage by observing air pressure and media size, without the use of water. Perhaps the water helps to "soften the blow" so to speak, by having the media in the mix. But as shown in the water jet example, which obviously uses a different delivery method than what you are using, water is not the secret Elixir of Unicorn blood.. Any process used incorrectly may cause damage. Accurately identifying the cause is the secret to corrective action in that method.

Last edited by MP&C; 04-27-2015 at 09:18 AM.
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