Graham Fredeen Posted August 16, 2006 Share Posted August 16, 2006 Greetings all. I have a qestion in reguards to obtaining oil for heat treating blades. As I have increased my blade production and blade size I realize that I need to get a large quantity of oil for quenching durring the heat treatment. Previously to this I was using a small amount of oil (say about a gallon) for quenching, as I was only doing smaller knives, one at a time. But with larger blades and more blades being treated at a time, I need some larger amounts of the stuff to prevent it from reaching flash point and causing a fire, and to ensure a full quench for the entire blade. So, my question is, firstly what sort of oil do you use for quenching, where do you get it, and the price (roughly, I know it will vary per region)? I know where to get smaller amounts of vegetable oil, peanut oil, and automotive oils, and the like, but by the time I purchase the quantity I need (probably 5-10 gallons or more possibly) I will have spent a large amount of money, which is something I lack at the moment. So I suppose I am looking for the cheapiest way to go to get the job done. Any help is greatly appreciated. Tar Alderion Quote Link to comment Share on other sites More sharing options...
Nolano Posted August 16, 2006 Share Posted August 16, 2006 Well, mostly I use old car oil, stuff thats been changed out already, and I usually get it for free. However, I would prefere vegetable oil for blades, as it doesnt leave the blackened finish you get with auto oil. I despise the smell of oil quenches, though, using automotive oil makes it smell like your cars transmission went out, and using vegetable oil makes it smell like your local mcdonalds burned down. Quote Link to comment Share on other sites More sharing options...
cheftjcook Posted August 16, 2006 Share Posted August 16, 2006 Tar Alderion, Any and All food establishments are glad to give you there old fryer oil. We were throwing away, "properly disposing of(grin)", about 40 to 50 gallons a week between a few places. Kitckens, depending on locals laws, usualy have to pay some one to take it away and recycle. So for some one to come and take it for free, I'm happy. We now have a guy with a desiel type converion for his truck that uses strained fryer oil as the fuel. He stops by regularly and we are happy to help him, we save it for him in containers he gives us. I don't fully understand how the conversion works but he runs for free and we don't have disposal issues. As I was taught, the oil viscosity does not change only the dirty particles in the oil and there effect. So if you strain it well, it should work well for you. Flash point on fryer is very high as well and is ment for heavy use. And depending on what was cooked in it you also have a neat smell of fries, fish & Chips.(grin) Hope this helps TIM Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted August 16, 2006 Share Posted August 16, 2006 I was in "wally world' just the other day and happened to notice they are clearing out the summer time BBQ items. They had a 5 gallon turkey fryer Pot & lid with a thermometer, 4 gallons of peanut oil, a propane burner with regulator & hose as well as a anti-tip stand all for under $50.00 Come to think of it I should go buy one if they still have any left. That would be just the perfect thing for bigger blades. Hope this helps Jens Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted August 16, 2006 Share Posted August 16, 2006 Burnt motor oil is a very slow quench. Too slow for most oil hardening steels. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted August 16, 2006 Share Posted August 16, 2006 Motor oil often can have gasoline mixed in, which can be scary at best and deadly at worst. ATF (automatic transmission fluid) works reasonably well as does most any vegetable oil. The used fryer oil route is a good one and environmentally friendly but I simply bought 10 gallons of Texaco Quench-Tex about 20 years ago and keep it in a galvanized milk can. Was about $3 a gallon then - don't know if the cost is higher now. With the milk can, moisture is kept out and the lid can be flipped back on in case of a fire. I'm quite sure this supply will last me the rest of my smithing career since very little is consumed or spilled during use. Quote Link to comment Share on other sites More sharing options...
Dodge Posted August 16, 2006 Share Posted August 16, 2006 I haven't done that much oil quenching, but I concer with cheftjcook on the veggie oil source. Fast food restaraunts will probably give it away. At least thats what the articles have been saying as a source for bio-diesel base. Quote Link to comment Share on other sites More sharing options...
nc_cooter Posted August 16, 2006 Share Posted August 16, 2006 I use canola oil from wally world to quench my 1095 blades. It has a high flash point and is cheap. Preheat to about 130F and it works great. Quote Link to comment Share on other sites More sharing options...
Graham Fredeen Posted August 17, 2006 Author Share Posted August 17, 2006 Cost and avaliability was the main issue I faced. I think I might go hit up one of the fast food places about here and see what I can do. That sounds like the best route. I thought of checking with an automotive repair/oil change place to see about that, but I really didnt want to mess with automotive oil, as the various reasons stated by Tyler and Nolonao. Should have though of the fast food places myself, but didnt think of it. Anyway, thanks for the ideas I should be able to make something work now. Tar Alderion Quote Link to comment Share on other sites More sharing options...
Nolano Posted August 17, 2006 Share Posted August 17, 2006 Tyler, Ive never found automotive oil to be a "too slow quench", I've made plenty of tools with it. At my local Costco(Huge warehouse store that sells in bulk) I remember you could be an extremely large bottle of soybean oil(I'd guess 2-4 gallons, it only measured it in pounds, strangely) for $13. Quote Link to comment Share on other sites More sharing options...
Bob H. Posted August 17, 2006 Share Posted August 17, 2006 Actually, used motor oil can carry a wide variety of contaminants. Some very nasty stuff can be in there, that you do not want to breath. I currently use new ATF fluid, but will go to Sams Club and buy the soybean oil they have, same as Ellen has suggested in the past. Something like 5 gallons, for a very low price. Bob Harasim Coyote Forge Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted August 17, 2006 Share Posted August 17, 2006 Tyler, Ive never found automotive oil to be a "too slow quench", I've made plenty of tools with it. At my local Costco(Huge warehouse store that sells in bulk) I remember you could be an extremely large bottle of soybean oil(I'd guess 2-4 gallons, it only measured it in pounds, strangely) for $13. Maybe you are quenching at too high a temperature. Quote Link to comment Share on other sites More sharing options...
Nolano Posted August 17, 2006 Share Posted August 17, 2006 Hmm, its working fine for me, so I must be doing it wrong. Of course! But yeah, I am going to get a few gallons of veggie oil soon. Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted August 17, 2006 Share Posted August 17, 2006 Notice I said BURNT motor oil. Not sure about new stuff Quote Link to comment Share on other sites More sharing options...
Nolano Posted August 17, 2006 Share Posted August 17, 2006 Ah yes, well, this stuff is not burnt, merely old stuff that has been changed out after its recommended service life. Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted August 19, 2006 Share Posted August 19, 2006 I have an oil quenching question. Say with water and a 5160 knife blade, you heat it up to critical/non magnetic and quench it(hardening?), then temper, right? But with oil, because it is not such a quick rate of cooling, woiuld a knife blade still need to be tempered, or could it just be hardened in the oil and be usable and tough? Quote Link to comment Share on other sites More sharing options...
Mills Posted August 19, 2006 Share Posted August 19, 2006 What is "burnt" motor oil? Quote Link to comment Share on other sites More sharing options...
sandpile Posted August 19, 2006 Share Posted August 19, 2006 A.M. carbon steels irregardless of quenchant have to be drawn back to the hardness you want. If left completely hard, they will break like glass went dropped. Chuck P.S- Don't put 5160 in water for a quenchant.Grin. Quote Link to comment Share on other sites More sharing options...
Ellen Posted August 19, 2006 Share Posted August 19, 2006 35# of new soybean oil at Sam's Club for $13. That's about 5 gallons. Works great, no smell, much higher flash point than most other oils. Yes, you still need to temper the blade. The kitchen oven at 350 to 400F, depending on your desired result and starting steel works great. You'll be glad it's not used cooking oil when you temper the blade inside the house. Make sure you buy the pure oil, some of the frying oils have additives in them and I am not sure how that will affect the quenching results. Use a large enough quantity of oil for the blade, stir in a figure 8 pattern, pull the blade out when is cooled to a black heat, and let it air cool, then temper it in the over. The air cool from a black heat to a "hold in your hand heat" will give you about 15 minutes of crucial time for the transformation of the martensite in the blade steel and will eliminate the need to "triple temper" the blade. I've used this technique on O-1, 1095, and 5160. Quote Link to comment Share on other sites More sharing options...
Graham Fredeen Posted August 19, 2006 Author Share Posted August 19, 2006 Sandpile is right A.M. If you quench 5160 in water you will crack it, unless you are extremly lucky, but in most cases it will crack. And if it doesnt crack it will be brittle beyond any use. You must use oil. And, if you harden a blade and it does not need tempering afterwards that means it did not harden in the first place. You must always temper or your blade will not be of any service and will break with the least amount of stress. When I get some more $$ I might check out that soybean oil, sounds good. Tar Alderion Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted August 20, 2006 Share Posted August 20, 2006 Sandpile is right A.M. If you quench 5160 in water you will crack it, unless you are extremly lucky, but in most cases it will crack. And if it doesnt crack it will be brittle beyond any use. You must use oil. And, if you harden a blade and it does not need tempering afterwards that means it did not harden in the first place. You must always temper or your blade will not be of any service and will break with the least amount of stress. When I get some more $$ I might check out that soybean oil, sounds good. Tar AlderionA.M. carbon steels irregardless of quenchant have to be drawn back to the hardness you want. If left completely hard, they will break like glass went dropped. Chuck P.S- Don't put 5160 in water for a quenchant.Grin. I have never had a problem, I use water for most everything, and i still have a center punch that has been used and abused that I hardened and tempered in water, last year, it is 5160, and it shows no cracks, no nothing. If you want to know the trick to it let me know. Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted August 20, 2006 Share Posted August 20, 2006 And that punch has been abused, not abused abused, but let me just say i hot punch EVERYTHING, and use it as a drift as well too. I have flattened the tip more than once, re ground the tip and used it again, and like I said, it shows no cracks, no nothing. But it could also be my punching technique, I just drive the punch right through, then knock off the little slug. Quote Link to comment Share on other sites More sharing options...
Graham Fredeen Posted August 20, 2006 Author Share Posted August 20, 2006 Well, A.M. as for your punch and water hardening. If your water quenchant was warm/hot that could have slowed the quench enough not to cause cracking, or if you quenched below the critical. Or you were just fortunate not to have a crack form. Plus you mentioned tempering, if you tempered enough (500 F + or when it starts to turn blue) the punch should work just fine. Plus you said you hot punch, everytime you punch you heat up the punch itself, and if it gets hot enough you temper it. If you have flattened the tip multiple times that indicates that the heat treatment has gone due to lots of heat (either in the initial tempering or through its life of punching.) I have experimented with 5160 and water quenching a few times and the first time I quenched a section of it from the critical, I got a crack. The rest of it was brittle enough to break over the edge of the anvil. I also have tried heating the water and then quenching, this tended to reduce the tendency for cracking but it did not help the brittleness much, which means a good tempering is needed. But for the most part, I find its best just to use the oil and not have to worry. Tar Alderion Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted August 21, 2006 Share Posted August 21, 2006 Oh cool. Yeah my water is pretty warm all the time, except if I get to the shop in the early morning. It's a small little bucket, so a few quenches heats it up pretty quick. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.