The Best Laid Plans

[rbscebu]

The last Cadman "Bengall" PIF was won this morning. I thought that I should start preparing the next SR PIF.

@LesC kindly donated a new Titan ACRM-2 T.H.60 kit to me for this purpose. The SR still had its factory edge so it would need honing from bevel set to shave ready.

Sharpie test showed a multi (2) faceted bevel as usual with most factory edges. I taped the spine and set about correcting the bevel on a 400 grit synthetic. With the multi facets removed, I removed the tape and moved on to a 1k synthetic for a rough bevel set.

As the 400 grit striations were being removed, I noticed that there was one that just persisted at about 19mm from the heel. This "striation" started as the edge and only went up about half the bevel height. Hmmmm, there is something not right here.

Out came the penetration dye for a crack test. Under a good light and with magnification all was revealed. There was a crack going from the edge up to almost the top of the bevel. I could have just ignored it, afterall if was only going to be a PIF, but then my OCD kicked in.

Out came the 320 grit SC stone. This blade was 23mm (7/8). Using the SC stone, I bread-knifed the edge, removing about 3mm. That got all of the crack out - I hoped. I was now left with a 180° bevel angle!

With new tape fitted, I returned to the 400 grit synthetic and set about restoring the bevel. That took some work (and tape). I re-flattened that stone about four or five times during the bevel restore.

Once I had no reflected light off the edge, it was back to the 1k for a new rough beve-set. All went well and, with another dye test, no more crack was visible so the bevel-set was finished on a 3k synthetic.

From the 3k, it was an 8k synthetic and then on to the lapping films; 5μm, 3μm and 1μm. The blade was finished on a diamond pasted balsa strop progression; 0.5μm, 0.25μm and 0.1μm.

Shave test on Monday.

 

[Garry357]

The last Cadman "Bengall" PIF was won this morning. I thought that I should start preparing the next SR PIF.

@LesC kindly donated a new Titan ACRM-2 T.H.60 kit to me for this purpose. The SR still had its factory edge so it would need honing from bevel set to shave ready.

Sharpie test showed a multi (2) faceted bevel as usual with most factory edges. I taped the spine and set about correcting the bevel on a 400 grit synthetic. With the multi facets removed, I removed the tape and moved on to a 1k synthetic for a rough bevel set.

As the 400 grit striations were being removed, I noticed that there was one that just persisted at about 19mm from the heel. This "striation" started as the edge and only went up about half the bevel height. Hmmmm, there is something not right here.

Out came the penetration dye for a crack test. Under a good light and with magnification all was revealed. There was a crack going from the edge up to almost the top of the bevel. I could have just ignored it, afterall if was only going to be a PIF, but then my OCD kicked in.

Out came the 320 grit SC stone. This blade was 23mm (7/8). Using the SC stone, I bread-knifed the edge, removing about 3mm. That got all of the crack out - I hoped. I was now left with a 180° bevel angle!

With new tape fitted, I returned to the 400 grit synthetic and set about restoring the bevel. That took some work (and tape). I re-flattened that stone about four or five times during the bevel restore.

Once I had no reflected light off the edge, it was back to the 1k for a new rough beve-set. All went well and, with another dye test, no more crack was visible so the bevel-set was finished on a 3k synthetic.

From the 3k, it was an 8k synthetic and then on to the lapping films; 5μm, 3μm and 1μm. The blade was finished on a diamond pasted balsa strop progression; 0.5μm, 0.25μm and 0.1μm.

Shave test on Monday.

Do you have any photos, before and after would be good,

 

[rbscebu]

Do you have any photos, before and after would be good,

I didn't take any before photos as what I found was unexpected and so fine that I would not have been able to photograph it. After photos will be posted when the PIF thread is started.

The 7/8 SR is now a 6/8.

 

[Gargravarr]

It shouldn't be up to the end user to spot cracks in a factory edge. Quality control at the factory should pick that up. There's no doubt that Chinese factories have the technical skills to do that (it's pretty basic), though it has to be said the quality of Chinese steels leaves a lot to be desired. They can be made to do a fine job in this case though, as tempering requirements are pretty simple.

When I was working as a blacksmith, almost all of the tool steels I used by choice were US-made, as it's so much easier to work with a product of known and consistent quality. (I was in WA at the time, and other steels were available, but usually at higher prices.)

 

[rbscebu]

It shouldn't be up to the end user to spot cracks in a factory edge. Quality control at the factory should pick that up. There's no doubt that Chinese factories have the technical skills to do that (it's pretty basic), though it has to be said the quality of Chinese steels leaves a lot to be desired. They can be made to do a fine job in this case though, as tempering requirements are pretty simple.

When I was working as a blacksmith, almost all of the tool steels I used by choice were US-made, as it's so much easier to work with a product of known and consistent quality. (I was in WA at the time, and other steels were available, but usually at higher prices.)

Made in Taiwan of Japanese steel. I have also experience cracks in new Dovo and Thiers Issard blades, however TI was the only manufacturer who refused to replace or refund.