Temper Help ....?

Don't trust tempering colors, unless it is your ONLY option for heat control. If that is the case, the piece needs to be taken to bare metal and completely degreased. You also have to do it in one shot or you'll be temper coloring the thin oxides you previously brought out.

I personally wouldn't nitre blue any blade intended for real use. 500-600F, even for a short time would certainly effect thin cross sections.

You can get some interesting colors by applying cold blue solution prior to tempering... and it wears much better.
 
ib2v.. wow, started off very informative and friendly (was gonna thank you).. then went all jerk on me. i dont know what your talking about. if i wasnt interested, i wouldnt be here and i wouldnt have been tempering metals the last few days.. geez
anyway, i should mention, again, im more interested in this with tomahawks, rather than knives (i shouldve worded this better from the beginning).
ive been getting good, uniform results now. seems the more polished the hawk, the more uniform the color (using an oven). i did some in full blue but started stopping some in the brown'ish stage (not as soft, i guess.. and looks maybe even better than blue?)..kinda copper looking.
i seen an old school blacksmith using a coal forge but for the harden and temper, he had a bed of regular charcoal. he said it was a more even heat than the forge (not hot spots) and that it heated the metal to critical temp (for the quench) slower, and therefore was more "forgiving", as it would be harder to go way over critical temp without noticing. he would temper by rigging up the item to be tempered above the bed of coals and would often turn it (kind of like roasting a pig) until he reached a nice even color of whatever temper he was looking for. didnt use any thermometers or anything (did have a magnet).
and again, im kind of more interested in temper colors for functional BUT MORE DECORATIVE (<<thats a quote) TOMAHAWKS.
 
Don't trust tempering colors, unless it is your ONLY option for heat control. If that is the case, the piece needs to be taken to bare metal and completely degreased. You also have to do it in one shot or you'll be temper coloring the thin oxides you previously brought out.

I personally wouldn't nitre blue any blade intended for real use. 500-600F, even for a short time would certainly effect thin cross sections.

You can get some interesting colors by applying cold blue solution prior to tempering... and it wears much better.

yeah, i have been bare metal, full degreasing it. ..and thats why i was wondering about how long it would be at 500-600 in the salt bath, as i explained to that guy previously that , that is the exact temperatures im already using without the nitrite stuff (and its only in about 20 minutes).. thank you , very informative..and friendly
edit: oh yeah, and ive used cold blue alot, for years. guns and hawks, no knives i can remember blueing. most of my personal user hawks, ive cold blue'd. i got one or 2 plain ones
 
Rick,
Surprisingly, it doesn't affect the edge much at all. Sharpening the blade probably removes any lowered hardness steel. The drop would only be a point or two, and a few microns deep anyway.
The rest of the blade isn't affected any.

Conversion of martensite to pearlite is a time and temperature process. Temperature is heavily weighted, but time still plays. That is why you can snuff out a candle with your fingers, wave your hand over a camp fire, or quickly push a hot blade back on the anvil by nudging it with your thumb.
 
Perhaps, I just don't understand the "salts" process then, Stacy. How long of a dip are we talking and does the blue develope as fast as cold bluing?
 
The few axes I've seen tempered were done by heat transfer from a red hot lump of steel.
The hot steel was put on a square of ceramic blanket and the axe head was put on top with the poll centred on the hot steel and the edges not in contact with the heat source.
The heat transfers from the poll to the edge and you look for a decent blue on the poll. By the time the poll is blue, the edges are usually
straw. It's kind of differentially tempered but no real dividing line to give a Hamon.
 
IMG_2180.jpg
[/IMG] that's all i was going for. didnt take any pics of the blue ones but they looked pretty too. it seems tempering a tomahawk to brown or blue is ok? i mean, from what i understand now, blue is to soft for a knife and about as soft as you'd wanna go on a hawk? and the brown/copper color would leave it a little harder than blue? The 500-560'ish range is good for tempering hawks (even if youre not going for color)?
 
Basically, in and out after a few seconds. Fittings and guards can be left in longer. 500-600 works about right. Too hot and the color turns sort of grayish.
Start at 500F and see how the color comes out. Raise it 25 degrees and try again, until the color is what you want. Clean and polish before coloring.
 
Basically, in and out after a few seconds. Fittings and guards can be left in longer. 500-600 works about right. Too hot and the color turns sort of grayish.
Start at 500F and see how the color comes out. Raise it 25 degrees and try again, until the color is what you want. Clean and polish before coloring.

...good to know ... now that ive done a few!! :grumpy: (i think i was at 500-520'ish for this one..to get the "peacock" blue i got it down at about 560-570'ish) started off at 590 and got a nice blue quicker, and more than once but had some start "going grey", so i cut back a tad and its been working well.
 
Sorry I hurt you feeling by stating that you had obviously not spend much time reading the stickies.
 
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