How definitive is the cold blue test?

Tyrade83

Tyrade83

Half man, half bear, half pig
Joined
Aug 17, 2010
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I've seen it said on here, that a way to test to see if an older Busse is INFI is to apply some cold blue to the edge and if it discolors, then it's most likely not INFI. How accurate is this? Is there any way that an A2 blade wouldn't blue? I have an older Busse that I was almost positive was A2, but I tried to blue the edge and nothing happened. I tried a blade that was definitely INFI and got nothing either. Then I tried on some SR101, and it went blue instantly. Could I have a rare bird?
 
it wont blue with wax on it, possibly also some of the fancy corrosion inhibitors, and it should be degreased
 
It's a BBSHSH Humpback. I didn't think there were any made in INFI. I'll try degreasing, and give it a stropping, then try the test again
 
Make sure the strop isn't loaded with anything, especially oil, since leather retains chemicals for a very long time and it could undo your degreasing efforts. May not even need to strop it, just wipe it off with a paper towel.
 
if the edge is highly polished A-2 it will also be much harder for it to penetrate possibly providing a false positive.;)
 
I Cold blued my NMSFNO ?
It would not take on the top part around the scales but the Blade did no problem ?

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I've bever heard that before...?

Tyrade83 said:
I've seen it said on here, that a way to test to see if an older Busse is INFI is to apply some cold blue to the edge and if it discolors, then it's most likely not INFI. How accurate is this? Is there any way that an A2 blade wouldn't blue? I have an older Busse that I was almost positive was A2, but I tried to blue the edge and nothing happened. I tried a blade that was definitely INFI and got nothing either. Then I tried on some SR101, and it went blue instantly. Could I have a rare bird?
Click to expand...
 
Well, I gave the edge a quick stropping, and then degreased with alcohol, and still got no coloration from the cold blue. Still not sure what this means. Maybe a trip back home to Wauseon is in it's future.
 
I don't think you can ever get any steel clean enough before blueing. I think that is why David Brown had trouble getting his blade to blue near the scales in the above photos. Some contaminant was probably still present. Boiling in a degreaser may be needed. Maybe more than one type of degreaser. When we work and polish an edge, we put all kinds of contaminants into the steel. Maybe you should grind off a quarter inch and try again, ha, ha.
 
longun said:
I don't think you can ever get any steel clean enough before blueing. I think that is why David Brown had trouble getting his blade to blue near the scales in the above photos.
Click to expand...

Not really the case

I personally in my case think it has something to do with the "grain" structure of the steel.

The only place the blueing would not work is on the spine where the scales were. No problem on the melt down spine of the knife or talon holes, just the two places where it is ground to meet the scales and they were degreased as best I could with carb cleaner and only carb cleaner. The sides of the blade had the same carb cleaner treatment.

The edge was blue too but I sharpened or stropped off the blue.

INFI from what I understand is a carbon based steel and will rust or Blue (a controlled rust) I am not a metallurgist or anything just my limited info.

Garth or Jerry will say for sure.

This was a coated Blade that was stripped and the scales convexed I will be beating it up a bit this weekend so we will see how well the blueing holds up.

I have heard the only way to know for sure is to send it back to the shop and something to do with the color of the sparks it throws when ground or sharpened will tell you for sure.
 
Ok, I ground the edge back a quarter inch with my bench grinder and now it's blue. Problem solved, I guess it is A2 after all
 
Man. Don't sound so disappointed. That old A2 is some serious stuff. The foundation of hard use was found upon it. Some folks even prefer the A2
 
Oh, I'm not complaining at all. I want to give some A2 a workout. I only wanted to test it out of curiosity. And no, I didn't actually take a BBSHSH to a bench grinder :D
 
My point of saying we can't get things clean enough might be misunderstood. Some of the hardest things to get clean and nicely blued are items that have been put on the polishing wheels. The compound is impregnated into the steel and is hard to get out. I don't believe simple cold cleaner will do it all. That is what I meant about grinding away a quarter inch, just to get to clean steel. I wouldn't do it, it doesn't matter that much. And David Brown is right, there are some steel alloys that will not blue worth a hoot. Winchester 94s from the 70s era come to mind. But I think that was kind of the point of the test, right?
 
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