dickb Posted June 24, 2017 Share Posted June 24, 2017 I'd be interested in learning the pros and cons of tempering to about 400 degrees Fahrenheit by immersing the work in a pot of heated oil. You could measue the temperature of the oil with a deep frying thermometer of maybe a thermocouple . There are plenty of oils (peanut oil, soybean oil, etc.) with smoke points higher than 400 degrees. Thanks Quote Link to comment Share on other sites More sharing options...
Hotshoein4 (Mark) Posted June 24, 2017 Share Posted June 24, 2017 At that low of a temperature it shouldn't matter? I feel a science experiment is coming on soon... Would it stay warm enough for long enough to get a proper temper would be my question. Quote Link to comment Share on other sites More sharing options...
bluesman7 Posted June 24, 2017 Share Posted June 24, 2017 A friend of mine was doing that using a PID controller to keep the oil at temperature. He has since moved to a salt bath. I think that he is using bluing salts Quote Link to comment Share on other sites More sharing options...
Work With Nature Posted August 29, 2017 Share Posted August 29, 2017 I was having the same question and found your post here. I did a search on the flash points of different liquids. Found two that may be suitable but at least one that I think could actually work. Would be great for people like me who could just heat a small pot with a thermometer for tempering. No oven. Guess which one Glycerin - celsius 290 / fahrenheit 554 Linseed Oil - celsius 287 / fahrenheit 548 Source: http://www.engineeringtoolbox.com/boiling-points-fluids-gases-d_155.html Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 29, 2017 Share Posted August 29, 2017 Watch out for pre-flash vapourization and BOOM! I like to use tempering tongs and so do a differential temper. They are tongs with heavy crossbars on the tips of the jaws: to use you heat them in the forge and grab the spine of the blade and let the heat travel making for a softer spine and a harder edge---as you quench in water when the edge is the correct colour. I even found a pair at the fleamarket once... Quote Link to comment Share on other sites More sharing options...
basher Posted August 30, 2017 Share Posted August 30, 2017 I tempered swords in mar quenching oil for a long time, but I have had the oil bubble up and empty its self a couple of times now and i no longer do it. The advantages are even heat distribution. but 450C oil is terribly dangerous and any unheated oil or water droplets turn it nasty quickly. Quote Link to comment Share on other sites More sharing options...
SLAG Posted August 30, 2017 Share Posted August 30, 2017 W.W.N., The price of glycerin may be prohibitive. Unless you live by, and have access to a fish processing plant. (a possibility in Kerala). Have you checked out the properties of peanut oil? It has a high flash point. Also, thank you for the engineering reference above. SLAG. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted August 30, 2017 Share Posted August 30, 2017 Nah, glycerin is a commonly used substance worldwide. It goes into pharmaceuticals, paint, resins, explosives, cellophane, cosmetics, sausage casings, Pop Tarts, pet foods etc. etc. We haul it on a regular basis at 45,000 lbs per load. I guess that doesn't mean you can easily obtain it in consumer level quantities though. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 30, 2017 Share Posted August 30, 2017 I have had trouble finding it in decent quantities retail to tan a snake skin before. Quote Link to comment Share on other sites More sharing options...
4elements Posted August 30, 2017 Share Posted August 30, 2017 Glycerin is a by-product of making bio-diesel from waste oils and fats. If you could find someone doing that it may be a source. Also suppliers for soap making. I haven't had a reason to look for it, so I don't know about availability and quantity. Quote Link to comment Share on other sites More sharing options...
Frosty Posted August 30, 2017 Share Posted August 30, 2017 Why let oil smoke at all? Put a cover on it and purge the air with your mig welder's shielding gas, even 75/25 it doesn't need to be inert just displace the oxygen. Oh heck a piece of dry ice or puff from a CO2 fire extinguisher will work. Open the valve so there's positive pressure in the tank, open the cap, slip the piece(s) to be tempered through a curtain, close the cap and set the timer. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Desmond Redmon Posted September 30, 2017 Share Posted September 30, 2017 In bulk I got it from a website called bulk apothecary. Of course that was after really odd questions at the pharmacy about why I needed it by the gallon... And the price was vastly cheaper. Quote Link to comment Share on other sites More sharing options...
anvil Posted October 9, 2017 Share Posted October 9, 2017 This from Tom Bredlow years ago. When tempering small springs, anneal, harden, then flash them in corn oil once or twice. According to him the flashpoint of corn oil is what makes a good temper for springs out of 10xx or W1 tool steel. Works for me Quote Link to comment Share on other sites More sharing options...
Angelfire Forge Posted November 10, 2017 Share Posted November 10, 2017 If you are looking for glycerin, try Craigslist. I have seen several biodiesel makers giving away 55 gallon drums of the stuff. They usually just want it gone. Terry Quote Link to comment Share on other sites More sharing options...
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