On Wed, 20 May 2009 02:15:40 -0500, James Waldby wrote:

On Tue, 19 May 2009 17:41:44 -0700, Gunner Asch wrote:
On Tue, 19 May 2009 19:22:44 -0500, "Karl Townsend"... wrote:
"Gunner Asch" ... wrote ...
On Tue, 19 May 2009 18:01:13 -0500, ... Karl Townsend wrote:
"Gunner Asch" ... wrote ...
On Tue, 19 May 2009 15:51:59 -0500, "Karl Townsend"... wrote:
Stainless steel fasteners?

The tank is cold rolled. Does it do any good to have a stainless
screw? Yhese would be a stone bitch to drill out when they twist
off.

Nuts and bolts Karl...nuts and bolts.

Sorry, guess i didn't describe what i'm doing well enough. If i use
screws they would have to be self tapping into cold rolled straps.

For the 11 gauge plasma tank that you are building????

yes, into the angle iron supports.

inside..or outside or on the bottom?

Some plasma tables use air bladders to displace water to
raise or lower the water surface level; others have a two-
compartment tank with no bladder, and use compressed air to
push water out of the lower tank to raise water surface level
in the upper tank. The top part of the lower tank is air-tight
and the water transfer pipe picks up near the bottom of the tank.

I think Karl's early post in this thread talked about a bladder,
but some more recent ones give me the impression there won't be
a bladder, just the two-part-tank arrangement, with a big flat
plate dividing the parts. Although I don't know whether his
plan has the angle iron supports above or below the flat plate,
if the supports were above it I don't see how he would get it
out again later (as he apparently wants to be able to do, for
maintenance). So, I think he is looking for fasteners to hold
the plate down, air tight up to say 3 psi, on top of angle iron
supports. It seems like an alternative would be a framework that
lays in on top of the plate and bolts to the tank sides with nuts
on the outside of the tank. This would stiffen the tank sides and
wouldn't make any holes in the plate, while holding it down
against gasket material on the angle iron. Or, if angle iron
were welded along the edges of the separator plate, the gasket
would be vertical, captive between the angle and the tank wall.
If holes are drilled in place and if the walls taper out just a
bit, then bolts will fit ok and assembly/disassembly is possible.


But.....why bother with all the internal workings? Yu need at
most....3" of water under your work piece and an inch of freeboard to
make sure it doesnt drip on the floor.

IRRC...its only going to be 6x10 feet in size...and its NOT going to be
used for rocket motors and large assemblies.

If he is actually going to cut assemblies...thats another story..but
then he is going to have to have a large liftable gantry for the torch
and moving parts and that becomes a much larger issue.

Im not seeing where all the complicated stuff is involved here.

Shrug..while not a "pro"....Ive a bit of hands on with plasma tables and
the side mounted milling cutters for using the same hardware for cutting
plastics and wood on the other side of the tank.


Gunner, scratching his head in a bit of confusion apparently.

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno