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raku & propane tanks

updated thu 31 oct 96

 

WardBurner@aol.com on sat 12 oct 96

Hi all,

I just received this email message this morning and felt the answer would
come in handy to others on the list Here's the question:

<<<a 20 gallon propane tank with a weed burner. I am not getting it up to temp.
quick enough. The tank freezes up fast. When I rolled the tank around a bit
it would give me more (since then, i have found out you're not supposed to
roll the tank). What do you suggest? Do i need a 40 or 50 gallon tank? Do I
need a regulator? Thanks a million if you can help! >>>>

What this person doesn't need is a weed burner! Now, I know lot's of folks
use weed burners for Raku, but that doesn't make it the thing to use. Check
the package the weed burner came in....does it say "weed burner/kiln burner"?
This is a prime example of "the cheap person pays the most". Wasted gas,
wasted pots, wasted time. A weed burner has a tiny orifice in it with no
regulator. This means a full propane tank in the summer may be putting out
250 PSI while a next to empty tank in the winter may be putting out 30 PSI.
This is what regulators do. Regulate the pressure so that it is constant. As
you can see, a full tank is putting out a tremendous amount of pressure which
draws the tank down too fast resulting in freeze up and stalling. Also, for
those that have put together their own systems without a regulator, they need
to know if their hoses can handle these pressures without rupturing.
DO NOT ROLL PROPANE TANKS AROUND OR TURN THEM OVER! Also do not use tanks
designed for liquid withdrawl, such a fork lift tanks. All burners are
designed to burn gas not the liquid which can be sucked into the regulator if
the tank is turned over or sloshed around. Even Liquid withdrawl burners
vaporize the gas before mixing it with air for combustion.
As far as this person's question about larger tanks; it may prove
unnecessary if the orifice is sized correctly and a regulator installed. Two
twenty pound tanks hooked together are better than one 40 lb tank. The
reason; twice the wetted surface area of liquid propane to boil off into gas.

Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com