niter bluing
- Thread starter curtisk
- Start date
EdCaffreyMS
"The Montana Bladesmith"
There recommended temp for using Nitre Blue is 570-650F, which would knock the temper out of most carbon/alloy blades. I have managed to get around it a couple of times by lowering the temp to 415F (which is what I temper most of my mosaics at) and allow the blade to soak in the Nitre Blue for an extended period of time (3-4 hours). The down side is that I've never been able to be consistent with it...sometimes, depending on the thickness/mass of the blade, it would come out splotchy or otherwise not like I wanted it.
For those reasons, I generally only Nitre Blue fittings. Nitre Blue does work well for the low temp side of a "salt" heat treat setup.
For those reasons, I generally only Nitre Blue fittings. Nitre Blue does work well for the low temp side of a "salt" heat treat setup.
EdCaffreyMS
"The Montana Bladesmith"
I don't think that would work. I can't give you a specific time, but would estimate that within less than a minute in the Nitre Blue, the thin cross section of a blade's edge would be tempered beyond use. It might be worth the effort to try soaking an experimental blade of the same material in the Nitre Blue at around 400F for an extended period of time to see how that works for you. Coloring a blade is always a give-n-take situation....we're always giving up one thing to achieve another. In this case we usually give up the blade hardness in order to achieve those "cool" colors. About the only way I've found around it is the low temp for long duration soak, or the use of multiple methods on the same blade, such as a combination of Nitre Blue, heat coloring, and baking lacquers.
I've actually had collectors who demanded that the blades be hot blued, even though I repeatedly explained that the temper would be destroyed. From those experiences I've come to learn that it's all relevant to what the individual deems most important...looks or performance.
I've actually had collectors who demanded that the blades be hot blued, even though I repeatedly explained that the temper would be destroyed. From those experiences I've come to learn that it's all relevant to what the individual deems most important...looks or performance.
curtisk
Well-Known Member
thanks again Ed
Thank you Ed. You make a good point "the customer may not always be right but he does have the cash."
Hmmm, does that make me a prostitute? Personally, I would never trade off performance for appearance. One of our SWAT guys wanted a combat knife and stressed a dark mat finish, but did give me a little artistic license. I blasted the blade (carbon steel) and went ahead and did the nitre. I must say I was freaking out the whole time! I agitated it about every 15 to 20 seconds and left it in for a total of 20 minutes. After cooling and cleaning it did have a mottled appearance in some places. I rubbed oil over it and “SHAZAM!”, all of the color blended together and there is not a hint of mottling. I plan on doing some edge testing tonight on some 1” cotton rope tonight. I reckon on the bright side of this venture, the main thing he will use the knife for is breaking glass (pommel of course). Not to mention showing off his new “toy” to the other SWAT team members.
I really appreciate your input and advice. I have only been at this for a little over 4 months, but I have to say this is a most rewarding “hobby”. I have always piddled with woodworking and blacksmithing (novice) but this is something entirely different. The joy, the pride, just plain old pleasure I experience from working a knife out of steel is absolutely amazing.
Thanks again for your help. And thank you very much for starting this forum; there is a wealth of experience and information on these pages. Who says you can’t teach an old dog new tricks? I’m 46 and still learnin’.
Thank you Ed. You make a good point "the customer may not always be right but he does have the cash."
Hmmm, does that make me a prostitute? Personally, I would never trade off performance for appearance. One of our SWAT guys wanted a combat knife and stressed a dark mat finish, but did give me a little artistic license. I blasted the blade (carbon steel) and went ahead and did the nitre. I must say I was freaking out the whole time! I agitated it about every 15 to 20 seconds and left it in for a total of 20 minutes. After cooling and cleaning it did have a mottled appearance in some places. I rubbed oil over it and “SHAZAM!”, all of the color blended together and there is not a hint of mottling. I plan on doing some edge testing tonight on some 1” cotton rope tonight. I reckon on the bright side of this venture, the main thing he will use the knife for is breaking glass (pommel of course). Not to mention showing off his new “toy” to the other SWAT team members. I really appreciate your input and advice. I have only been at this for a little over 4 months, but I have to say this is a most rewarding “hobby”. I have always piddled with woodworking and blacksmithing (novice) but this is something entirely different. The joy, the pride, just plain old pleasure I experience from working a knife out of steel is absolutely amazing.
Thanks again for your help. And thank you very much for starting this forum; there is a wealth of experience and information on these pages. Who says you can’t teach an old dog new tricks? I’m 46 and still learnin’.