[TheForge] oil temps (one more time)

[James Binnion]

On Nov 19, 2010, at 12:31 PM, Steve Bloom wrote:

> 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.

Something to think about, these vegetable oils are a complex combination of fatty acids each one with a different boiling point, flash point etc. As you heat them to extreme temperatures over prolonged time periods they are going to change structure from oxidation and evaporation etc and you will have a different oil than when you started. I don't really know what all the changes would do but I bet you will have to change oil fairly often. The good thing about the Park oil is it is engineered and tested to operate at those temps for prolonged periods. I know it is expensive and may be beyond the budget but there is a reason that commercial heat treaters are using it rather than say soybean oil because if a plain vegetable oil was just as good or nearly so then the commercial guys would not pay the price of the Park oil either. Just something to think about

James Binnion
jbin at well.com