New Ray Mears knife with marked blade

[Coach]

Hi, I recently bought a R.M. Woodlore Pro made by Emberleaf from Woodlore. It wasnt until after first use and cleaning afterwards that I noticed marks on the blade that look like the brown /purple discolouration you get on overheated metal. I took a photo and emailed Woodlore, not sure if they actually looked at the photo but the only response I got was an assurance of their quality control. Im worried that the blade has been weakened and may fail at a later date, can anyone offer advice please?

 

[Tiley]

Have you tried sending the pictures and your observations to Emberleaf themselves? As the makers, they should (a) know what has happened and (b) be able to suggest a remedy. It might be worth a try.

 

[swotty]

I'd be interested to see the photo?

Sent from Somerset using magic

 

[chimpy leon]

If you show the pic here there’s a good chance someone will be able to explain what has happened to the steel. It might put your mind at rest or give you cause to take it up with Woodlore.

 

[Stew]

Woodlore are the correct ones to raise the dispute with but pictures would certainly help us give a view

 

[Terry.m.]

I would definitely do as others have suggested, continue with woodlore as that’s where you bought it, also Emberleaf to make sure they have completed a visual.
The knife has to be fit for purpose, I have the Alan Wood one and it’s 100 pct.
If you are worried do not leave it.!


Sent from my iPhone using Tapatalk

 

[Coach]

I'd be interested to see the photo?

Sent from Somerset using magic

Sorry dont know how to put it on here, there doesnt seem to be an obvious mechanism.

Have you tried sending the pictures and your observations to Emberleaf themselves? As the makers, they should (a) know what has happened and (b) be able to suggest a remedy. It might be worth a try.

Thanks, will try that.

 

[C_Claycomb]

to post photos you need to use an external photo host, post on a mobile with Tapatalk, or upgrade to a paid membership.

Where on the blade are these marks?

On O-1, if it was fully hardened and tempered, then heated to a brown/blue colour, this would soften/toughen the material. If it is at the edge, it would be failing now, in that it would not hold its edge like the rest of the blade, failure by edge rolling. If it is on the spine or sides, this would just make the blade less likely to snap,

 

[Coach]

Thanks for the help. No idea what an external photo host is or Tapatalk etc so unfortunately will have to pass on the photo guys - the markings are halfway down the polished side of the blade below the ray mears/ emberleaf logo going down to the edge and in three waves going to the tip. Not sure what the technical term is for this part of the blade - maybe the grind?

 

[TLM]

On bright steel tempering is what usually gives the colours (it is not true colour but light interference in the thin oxide film). Darker colours mean higher temps and as C_C said, usually too soft for knives at the edge. To get a definite answer the blade would have to be tested for hardness, a simple procedure if one has the equipment.

 

[MrEd]

Thanks for the help. No idea what an external photo host is or Tapatalk etc so unfortunately will have to pass on the photo guys - the markings are halfway down the polished side of the blade below the ray mears/ emberleaf logo going down to the edge and in three waves going to the tip. Not sure what the technical term is for this part of the blade - maybe the grind?

If you message me I can send you my email and put the photo up for you

 

[Coach]

If you message me I can send you my email and put the photo up for you

Thanks but How do I message you?

 

[MrEd]

photo of the blade as emailed to me by @Coach

 

[C_Claycomb]

That doesn't look like anything I would be worried about. The photo isn't close enough to be sure, but a couple of possibilities come to my mind and neither would be cause for concern.

Could be residual colour from tempering that has only been partially removed by sharpening.

Could be light corrosion/staining that has occurred in line with where the blade was wrapped for protection during final finishing.

I would lean towards the latter. Blades are often taken to final finish before handle fitting, then one has to protect the blade from damage while the handle is glued and shaped. O-1 steel is prone to discolouration.

If the blade cuts well now, the temper is fine.

 

[Coach]

Dont think its staining, I unsuccessfully tried to remove it with Duraglit which had no effect whatsoever. The knife cuts well I just find it unsightly and for a little under £600 I expected it to be perfect not blemished.

 

[Stew]

If it was a temper colour from over heating then it would only be surface coloured. Polishing would remove it.

Staining usually goes deeper than just the top surface.

 

[Coach]

If it was a temper colour from over heating then it would only be surface coloured. Polishing would remove it.

Staining usually goes deeper than just the top surface.

Just shows you how much I know! I thought it was exactly the opposite, Ive left an empty pan on the hob in the past and got exactly the same discolouration which wont come out... even with metal polish. You live and learn!

 

[TLM]

Temper colours are made by an oxide layer with a thickness of about the wavelength of light, thin indeed. Usually taken away by the final buffing or cleaning.

 

[Coach]

So youre saying that although unsightly it shouldn't affect the performance of the blade.. or its value?

 

[TLM]

So youre saying that although unsightly it shouldn't affect the performance of the blade.. or its value?

The oxide layer itself does not, if it is a mark of too high tempering temp then yes. The proper hardness of the blade can only be accurately tested by measuring it, sharpening it does give some indication, an experienced maker can tell correctness fairly well by this method.