Thread: Thiers Issard microchipping

Ok thanks Gugi. I'll try to use math if the test shaving goes wrong :-)

It's a good advice thou. I think that measuring the angles could have sparred me many frustrations with old sheffield razors :-)

Well good news is that it shaves. Could be a bit sharper thou. The edge holds so I'll guess the next thing I'll have to try is to adjust the angle a bit more. Perhaps it's a dump question, but how do I measure the edge correct?

I thought I could just measure a triangle from spine to edge and calculate but as mentioned the grind is a bit of to one side.

Any suggestions?

This thread has the formula

http://straightrazorpalace.com/advan...-theories.html


And links to others that we have done on measuring angles

Hello again

I used the method mentioned. The angle was only 16,5 so I added and extra layer of tape, which brought the angle up to 17,5 degrees.

I then honed it again. It still holds the edge fine. Needs a test shave thou.

For the fun of it I measured my favourite razor to. It's a Eicker Heartring and it shaves fantastic. The angle on that one was only 16,9 so it doesn't have to be within 17-20 degrees. The steel have a say to.

The Heartring has a nice soft and flexible steel that takes an edge easy and hold it very long.

I will try to measure more razors to see if they are within Gugis goal of 17-20 degrees. If not try to make them. I can't believe I never went down this road before. I've been honing razors many years now.

And I've been honing knifes a lot longer and every knife I hone I set the angle to 20 or 30 degrees. Simply amazing I never thought to do the same with razors!

Back to my TI razor. Thou the angle measured is within specs it still hold a problem. The grind is offset which means that the grinding wheel on one side looks larger then the other side. It's the amateur restore for sure. It now hold a form like a kamisori and I should probably try to hone it the same way?

The method for calculating the angle doesn't takes this into account so one angle is steeper then the other. However the razor shaves. It's not in league with my bests, but it works. Better then scrap :-)

There's an old thread where you can find dozens of measurements on razors that shave and the bevel angles can range from as low as 13 even 12 degrees all the way up to 25 degrees.

But the edges of the distribution are exceptions with few razors in there, most of them are around 17-18 degrees.

The real problem is towards the low angles, most steels at 13 degree bevel and below can not withstand the stress of shaving and the edge will crumble, while at 20 degrees they'll still shave just not be 'very sharp' (meaning the resistance cutting whiskers is higher).

The grind you're describing sounds rather weird - try to take a picture of it like the ones in The straight razor - Straight Razor Place Library

Normally, on a hollow ground razor that is set during the manufacture and doesn't change with restoration. But incompetent restoration can cause the two potential problems:
(1) reduce the spine width significantly in the attempt to conceal the hone wear on the razor which can reduce the bevel angle significantly
(2) overheat the blade especially towards the edge where it's thin and there is not much steel which can change the mechanical properties of the steel

If three layers of tape got you angle of 17 degrees it means that without tape it was below 14 and that's definitely way outside the norm for vintage TI, i.e. you likely have scenario (1) above. Whether you also have scenario (2) is also quite likely given that at 17 degree bevel angle it is not shaving solidly and you want to try an even wider angle. But sounds like it may not be completely trashed and with a lot of extra effort it could be a shaver.

In any case I don't think it's necessary to correct the bevel angle of every razor to a given number - there is a range that works and it's something that the manufacturer should be concerned with.
Few years ago Hart Steel started with a design flaw (or design execution flaw, regardless ending in flawed razors) and when the early adopters got poorly shaving razors the culprit was found rather quickly and Hart began paying attention to produce razors that would actually shave.
It's pretty safe to say that any manufacturer who sold more than 100 razors has managed to create a product that does what it's intended to do and that's what matters.

The problem arises only when a razor isn't performing correctly. Personally, I'd send it back to whoever sold it to me, but it's also possible to diagnose the problem and in some cases mitigate it to a degree sufficient to make the razor shave

Try doing 20 edge trailing strokes after edge leading before moving up in the stones. The idea is keep the foil edge in tact. Strop with pasted denim then clean leather.

Another idea would be to not foil the edge in the first place. If a foiled edge has been created, then I see no reason to try to keep it intact rather than eliminating it.

Thanks again. The tread is a bit old. The particular razor, never made a reasonable shave. I think that a bad restore attempt by previous owner was to blame.

The tempering of steel is destroyed. I can make a perfect edge, but it's deteriorating fast in use.

I still got it, but haven't used it since.

Guess it's going to end the days as spare parts.... It's a shame because it's really a fine looking razor.