Blue staining on blade?

My regular "connection" had a few new blades this week, and I had a question for the more experienced resto guys on the forum. He has a Boker King Kutter with MOP-like covered tang and plain bakelite scales. The face of the blade has blue-ish wavy lines running along the edge, parallel to the bevel. These lines do not appear on the back of the blade, though. It does not appear that there had been any grinding done on the blade, and I really don't think that someone would have hit it with a torch for any reason. If the blade had been heated to the point of having some negative impact on the metal, it would have done it to both sides, right? I mean, these things are so thin it is not as though it would not conduct the heat to the other side of the blade. What else could it be? Could some type of oil left on the blade have stained it or discolored the metal in some way? I was going to pass on it, but saw a resto of a covered tang razor on the Gem Star site. Now I want to give it a shot.

You should know...pics. Pics tell much more than words.

Well, as I did not get it, I really couldn't snap any photos yesterday. That was yesterday, though. Today I went back and got it. Told him that I wanted to try putting an edge on it, and if it took I would come back and square up with him. He had no problem with that, so I am going to clean it up a bit and I guess send it off to someone to have it honed. I am leaning toward it being fine, as a thread that I saw earlier had a post by holli4 about a blade he owned having this type of discoloration. He said that it could have been caused by lather being left on for too long? The inside of the scales are nasty as shit, and seem to have a crusty white layer of film on them, even where there was no contact between scale and blade. the only defect on the blade is that the MOP tang is cracked off at the end of the monkey tail, just at the tiny pin. Blade has a lot of surface rust, but still has the etching. It almost seems as though something was left on the blade, then as the razor was shut and laid down, whatever it was settled against the spine close to the end, and along the line of the belly a bit away from the blade. I guess we will see. I tried to take some pics, but it is hard to get them to come out. Hence so many eBay purchases showing up at our doors warped and burned, eh?

Just looking for a more generalized answer by folks about what ELSE could cause this type of "staining". Aside from the rust, the blade has minimal, even hone wear, and seems as though it was not abused. Maybe it was just put up in a hurry the last time it was used and left for a while?

I guess the better question would be this:

What can I try to do to remove this blue if it is just a stain that would not work if it were discoloration from heating the blade? Is there anything that I can try that would not remove heat discoloration but WOULD remove surface staining?

I have had somthing similar on two of the razors that I picked up and I was able to remove it. I think its just discoloration from lather. I layed the blade down on a scrap of leather to protect it, then I took another 1" wide scrap of leather that I had rubbed liberally with green honing compound (Cr3O2) (from a woodwork supply store if you don't already use it) and rubbed/buffed the marks out with just finger pressure on the leather. One caution... if there is gold wash decoration on the blade it'll remove that too...

Tried to hit it with some very fine steel wool, then said screw it. Used some 1000 grit paper and the thing looks good as new. didn't use much pressure at all, and the discoloration was removed very very easily. Looking at the blade now, there is no trace at all of any of the staining. I actually saw some of the stains on the stabilizer, close to the spine as well, and there is NO way that this blade had been exposed to enough heat to do that. I think I might be out of the woods on this one! barely detectable frown, and I mean BARELY detectable. Other than that, I think that I might have scored. Five bucks well spent. Hopefully.

If you gave five bucks for it, it's a safe gamble & sounds like it would clean up well. Good find!!

I had a razor that had similar characteristics as you describe. Some Maas and the discoloration was gone. The razor was fine and the blue staining was not indicative that the blade had lost temper due to heat. It was fine.

Chris L

Exposure to very simple acids, like those found in juices and organic things will cause a light patina that can be yellow, green, blue. I would suspect that someone used the razor to cut something and perhaps merely wiped it dry without cleaning it further.

You are correct about colors related to overheating, especially in thin sections like razors. There would have been a matching discoloration on both sides. Although those are oxides as well and could be removed by simple polishing. There is no way to remove patina and leave the overheating colors behind or vice versa.