[TheForge] oil temps (one more time)

[Steve Bloom]

At 02:44 PM 11/19/2010, Jerry wrote:
>  You can also buy heat transfer oils made for things like tar kettles [snip]

I got a quote back from Park - $223 per 5 gal pail (plus 
shipping).  At the local market, soybean oil (at 466 F flash) is 
$7.99/ 1.25 gallons or $32 for the same amount - a mere 1/7th of the cost.

I did run a steam experiment this afternoon - used my low temp salt 
pot (7" diameter x 18" deep) to run 2+ gallons of soybean oil up to 
375 (the 110V water heater element and a variac had no problems doing 
that) - took about 30 minutes. Coated an 18" steel piece (1/8" x 1") 
with the usual satinite prep - thin overall coat and a thick partial 
coat. Ran that up to ~1600 F. Quenched in the slack tub for a 
5-count, wrist shook the piece on the way to the oil, and plunged it 
in.  There was a distinct boil -- maybe a touch more violent than a 
rolling boil.  There was no ejection of oil, no splatter, and no boil over.

When we did plunged our swords into hot salt (400 F+) (Don Fogg's 
course at the Folkschool), we also did not see a significant steam 
explosion effect - but that was a bath, not a tube.

  It looks like welding leathers, gloves and a face shield plus long 
tongs and head space in the oil tank (plus not standing directly over 
the tank) ought to be reasonable protection. It's no where near as 
exciting as a quench in used motor oil (for that surprised look of 
having no eyebrows <grin>).

Given this, it's fabrication time.

Steve