Thread: HHT on a new Dovo razor bought from SRD

Originally Posted by Cros

When I switched from Gillette Fusion to Shavette, I thought I was getting the best shave ever, so I guess everything is relative to the last best thing we have experienced in our lives... just saying...

Anyhow, for the time being I will concentrate on stropping and shaving and will get back to HHT when I hit the hones (I am planing to invest in a Coticule).
I am very grateful for all comments and advices, after all it is the experience sharing that keeps us from re-inventing the wheel. This new adventure keeps getting more exciting, and I am happy I gave it a try!

I think you should wait a bit with the hones, and especially naturlas and especially Coticules.
If you want to hone start with some synthetics for touch up, then gradually add lower grits to build a progression.
You will initially need to touch up only, then when you learn shaving technique and touch up you will be ready to jump into more serious collecting and honing.

Originally Posted by Jimbo

I always think of a test in two ways: 1. What is it's purpose?; 2. What's its fidelity to reality?

From the purpose perspective, in my opinion the purpose of the HHT is to give honers an idea of where the edge is before they test shave it. From that point of view it's not really something a user of a straight should care about but of course we all do It's a weird test because you can get a successful HHT on an edge that really shouldn't be shaving anyone as well as on a "good" edge. You can also get an unsuccessful HHT on a "good" edge. So you really need to know other bits of information for the HHT to be useful, and that information is often unknown to the end user but is known to the honer.

Second, fidelity to reality is quite important for any model-based test which is exactly what the HHT is. You don't shave by wafting your hair over the edge of the razor. Your beard whiskers are not head hairs, or dog hairs, or your wife's hairs etc. Your beard hairs are shortish, coarseish, and most importantly embedded in your skin. When you shave the edge rests on that skin. Is this even remotely modelled accurately by holding a hair in the air and seeing if it gets cut on a stationary blade edge? I don't think so, but others may disagree.

The only way such a divergent-from-reality test can even remotely hope to help you understand if an edge can shave you is by repeatedly, over time, noting the test results and correlating (not the best word, but will do) that result to what happens during the corresponding shave. That is the only way.

So really, the HHT test has two parts, and people either forget or ignore or don't know about the second and most important part. First you waft the hair over the edge (this is the bit people mistakenly think is the HHT). Second, and this is the most important part of the HHT, you test shave it and relate the results of the first part to the results of the second part.

Do this test several hundred independent times under varying conditions to get a decent sample size. Then you are in a position to know what the HHT is telling you.

James.

Inconsistency of HHT results is understandable to me. The only unanswered question to me remains the fact that different parts of the blade react to the same hair differently, i.e. the lower part simply ignores the hair, middle part cuts it with 'violin' moves, and the toe actually seems to do the job with a audible snap. Same blade, multiple tries with one and the same hair at a time - same result.

Without being a smart ass on my part, you consistently got the same variable results along the blade from the HHT yet got a very good shave. Now based on the consistent results the HHTs were giving you on that one razor coupled to the actual shave result that blade gave you would be lead to believe that you would have to hone all razors to give that same HHT result to get a good shave. What happens to the validity of that conclusion when you get a razor, hone it and it will not pass an HHT yet still provides a good shave? Better yet what happens if you hone a razor and it does the HHT the same all along the blade yet you get a poor shave? I believe people on here have had both happen. The type of results you were getting would indicate, to me, the relative value of an HHT in determining the shave readiness of a blade. To me that means an HHT is not all that relative an indicator of shave readiness as proven by the shave. That is what I think the results of your HHTs were telling you.

Bob

Bob, I have already been convinced that HHT is not a good indicator of shave-readiness. My question is different though: why does the same blade have different cutting properties along its edge? Can this be uneven honing, or maybe straight razors are honed that way on purpose by professional honers?

Sorry, I can not answer that specific question as I do not use the HHT when I hone nor have I done the HHT to razors I have received from various professional honers. The pro honed razors I just shaved with and all have done the job well. I don't use that HHT because I am not really sure what it reliable indicates if anything.

Bob

Originally Posted by Cros

Bob, I have already been convinced that HHT is not a good indicator of shave-readiness. My question is different though: why does the same blade have different cutting properties along its edge? Can this be uneven honing, or maybe straight razors are honed that way on purpose by professional honers?

Your HHT simply shows a variation in the edge's sharpness. Your shave test shows that variation is moot when it comes to shaving your beard unless you only shaved with the toe of the razor.