How do you clean this crazy thing?

**Psychmike22** · 09-03-2010, 02:23 PM

Hello Gents,
I recently purchased a Rotbart Mond-extra (see photo) DE blade sharpener.
I am working on cleaning it an I don't want to ruin it. On the inside is two rotating "strops" They feel like rubber but may be some type of hide. I can't tell.
How would you recommend cleaning this?

If anyone has a similar one and can tell me anything about it I would appreciate it.

As always I am great full that I have a place to ask such a question.

**edutton** · 09-03-2010, 03:06 PM

WOW! What a find! I'm envious! I thought I found one of these in an antique store the other day, but it wound up being just an old-fashioned pencil sharpener.

**Psychmike22** · 09-04-2010, 06:36 AM

Bump

**FL shaver** · 09-04-2010, 08:05 AM

Check that out!! What's that bring the effective cost per blade down to: 2 or 3 pennies?

**GDCarrington** · 09-04-2010, 08:24 AM

I have been told that these items work with carbon steel blades (Gillette blue blades) and will not work well with stainless steel blades because they are too hard to strop in this fashion.

**BladeRunner001** · 09-04-2010, 10:06 AM

That's is an interesting thing. If those things are "strops", they are made up of leather of some sort and you don;t want to ruin them by subjecting them to cleaning detergents and such. Can you take this thing apart? Does it look easy? if so, I would do that and clean the "strop" parts separately (conditioning, other...). The rest of the insides can probably be cleaned using some WD-40 or something and then you can put it back together.

**shecky** · 09-04-2010, 12:42 PM

I wouldn't really clean those strops, at least not in a traditional sense. Just try to preserve them.

If those drum shaped strops are rubber, you might want to leave them alone unless they're showing signs of deterioration. If they are deteriorating, maybe very light application of silicone oil might keep them in order. NO petroleum products (mineral oil based lube/solvents), however. They might cause rubber, especially old rubber, to decompose faster.

If they are leather, maybe some light application of mink oil just to keep them from drying out and shrinking too much.

As for the mechanism, unless it's frozen or grindy feeling, I'd avoid too much lube. If you must lube, apply sparingly with a toothpick only to critical ares such as pivots and gear teeth.

If the whole thing can be easily disassembled, then you can go to town cleaning the mechanism, being careful about the strop material.

I have been told that these items work with carbon steel blades (Gillette blue blades) and will not work well with stainless steel blades because they are too hard to strop in this fashion.

It may depend on the hardness of the blades. I would expect blades run to a higher hardness may be more worth stropping. Lower hardness blades would probably exhibit diminishing returns. According to Personna's industrial catalog, which lists some DE and SE blades, their stainless blades can come in a fairly wide range of hardness (page 2). It is, however, extremely difficult for the average person to make this determination without very specialized tools. And, of course, there's no telling how other manufacturers spec their blades.

While I think stropping would certainly extend the useful life of any blade, DE blades are often cheap enough that it makes little sense to justify the effort or cost of a special machine. It would be interesting to make an assessment of such a practice with modern blades using a repeatable and meaningful method.

**Psychmike22** · 09-04-2010, 01:23 PM

I cleaned the mechanics of it with some light oil and a cotton swab. i cleaned the strops with some Kiwi leather lotion. The outside has some significant rust that I will take a dremel to. It is mechanically sound. As the strops rotate they oscillate from left to right. I am not sure how to test the efficacy of the stropping though. Any ideas are welcome.

I video recorded the thing in action. I am not sure how to upload an AVI.