petek

What a wonderful project and show of creativity! Would you be so kind as to post a picture of the final burner plumbing?

Thanks for the input! Half the fun is in the experimentation, but it sure is good to have input to avoid completely re-inventing the wheel!

In a previous question I asked a few beginner questions about heat treating tools in a kiln - the advice given was extremely helpful. One more question, if you all will indulge my desire to use a heat treating oven for as many steps as possible... I've been experimenting with hardening and tempering my striking tools using only the oven and quenchant. This has been working great with the exception of producing a tool with a hardened striking end... a problem on a number of levels. I may have found a solution to this, but would like to run it by the experts here for a critique or suggestions. After tempering I've stood the tool up in a shallow metal dish with about half of an inch of water in the bottom, submerging the "business end" of the tool. Then in a darkened shop I've used an acetylene torch to slowly heat up the striking end of the tool to a very slightly red color (just off black) and held it there for a couple of minutes. Then allowed it to air cool, with the part that I want to stay hardened still under water. The thought being that I am not getting the tool over the critical hardening temperature with the torch but the heat should severely temper the striking end and the water should prevent further tempering of the part that I want to remain very hard. This seems to be working and filing the struck end "bites" a bit... Do I have a good procedure here, or is it back to the drawing (no pun intended!) board? Thanks! -- Pete

I was reading this piece: http://tidewaterblacksmiths.net/2.html from Dave Smucker of the Tidewater Blacksmiths Guild along with the books on the subject that have been recommended here and other blacksmithing sites. The above article distills a lot of the information down to the practical level for the blacksmith. About 2/3 of the way through the article he speaks of quickly transferring the quenched piece to the tempering oven to lessen the chance of retained stresses from the quench relieving themselves in the form of cracks. Thanks you all for your thoughts and bearing with my beginner questions! -- Pete

Thank you much for your input, I'll give that a shot. The aircraft mechanic in me wants to control the variables to a degree of perfection, but it appears in this case a forge and experience / practice may be just the ticket!

Thanks for your further thoughts on this. I've been focusing on S7 lately and have had pretty good luck austenizing at 1800 degrees (book says 1725, but it wasn't hardening at that temperature), and then using a forced air quench in front of an old furnace blower converted to a shop fan. For some reason it wouldn't harden on a firebrick in still air. Read some previous posts mentioning forced air, and that seems to get it hard. The advice regarding the hardened striking surface was a very good point. Would heating just the striking surface to 1500 or so with the torch and letting it air cool draw enough temper off to make a good striking surface? Advice much welcomed and appreciated! -- Pete

Thanks for your input, it's great to have such a wonderful resource to draw from... Now I just need to gain more experience and knowledge so that I might have some thoughtful replies in the future :)

This is my first post after weeks of reading through this wonderful resource - I've learned a ton and want to thank all of you for sharing your knowledge! I've worked with metal all of my adult life and have decided that it's time to learn more about the heat treatment process. My goal is to make the process as repeatable and accurate as possible - so that I can keep notes, control the variables (as much as possible), and learn from my mistakes (and sucesses, down the road!). I have a evenheat programable heat treating oven to work with. I would like to both austenize and temper using the oven, the problem being that it's not really possible to cool the oven from hardening temp to tempering temp quickly enough to prevent post quench stresses from building up to an unacceptable level (or just cracking the tool). The question is this, and any alternative suggestions are certainly welcome. Is it good practice to heat and quench the tools using the oven and appropriate quench medium, then immediately place the items in the kitchen oven for a pre-temper - to minimize stresses until the heat treating oven can be cooled and reset to the proper tempering temperatures? If so, what temperature would get the items stabilized until proper tempering can take place? The steels of interest are: 5160, 4140, H13, A2, S7, and W1. Thanks! Pete