View Full Version : Mashtun bottom domed up?

06-03-2005, 12:45 PM
I was rinsing my mashtun after a brew and I heard a big boom. I looked in the mashtun and the bottom was a dome instead of a cone.
My hot liquor tank is below the mashtun, so I assume the hot water(180 F) had something to do with the expansion.
Has anyone had any experience similar to this one or heard of this happening?
Do I need to put really cold water in the hot liquor tank?
Any suggestions would be greatly appreciated.
Michael Morris
Head Brewer
Capitol City Brewing Company

Sir Brewsalot
06-03-2005, 07:09 PM
Eek... that doesn't sound encouraging. See if you can get in there with a flashlight and look for any stress cracks on either side that could require repair. (More likely near welds in my very limited experience.)


Diamond Knot
06-03-2005, 08:52 PM
Sounds to me what you have is an "oil can" condition caused by the differing temperatures on each side of the sheet. The HLT is at 180F and you probably were spraying the top with cold water. One side is very hot, the other is very cold, and the conditions were right for an oil can "boom".

If you cool the system down, it should go back. If not, it may have to be coaxed gently back into the cone position. You can't change the properties of the stainless at such a low temperature.........just its geometry slightly.

Actually, oil can conditions are pretty common in larger sheet metal structures.