Guerilla restoration and so

[Matt]

Hi there, this is sort of a continuation of my John Barber thread, but I will share some other homegrown restoration tips as they go along.

Why guerilla? Well, I have no other tools than Dremel, some cutting/sanding/buffing wheels, a file, sanding papers, pastes and that would be all. Not much like serious restorers' workshops (while we're on it, I don't have any of that kind, either ).

The thing I found out recently, when I was unpinning a razor, is to apply a layer, or two, of masking tape on a scale, before you do the pin sanding. Although the pictures will show a razor with a tube fit into a pivot hole (an application as much useful), the idea is identical. You just stick masking tape on your work area and file through it. When sanding down the pin, it's preferable to use two layers, so that when you go through the first one, it's a warning sign that you should be extra careful not to ruin the scale below.


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Next there is work in progress with the John Barber. As I was mentioning earlier, I decided to upgrade (or pimp up, thank you, Pithor ) a pair of scales by adding white liners to it and then adding a dark wedge. The liners were glued with epoxy to the scales, than I had a hard time cutting them down to the shape of the scales. The thing was twofold: one, the liner material is pretty hard by itself (I don't actually know what this is, I'd describe it by feel and smell as some kind of stabilized paper, it definitely smelled like cellulose when it was burning during cutting - both this and the wedge provided by our Ray - thank you again), two - excess epoxy that came out wasn't making it any easier - quite the opposite, actually. I also sanded the scales a little, 220/500/1200/2000 progression and polished them. Now there's a (again, I bet it's some horn, judging by the smell) wedge glued in temporarily (CA), hole drilled through, and it needs proper gluing with epoxy.

If I don't screw this up, this might end up looking pretty good. :thumbup: I'll definitely will need to work some more on this blade, now the scales will be too flashy for it.

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regards,
Matt

 

[TM280]

Hi Matt,

Looks like you are doing good work on those scales. Try electrical tape instead of masking tape. It is much more wear resistant.:thumbup:

I think the white material may be the resin paper that knife makers use. It is commonly used for spacers in handles, I have been meaning to pick some up since it can be so thin while maintaining its integrity.

Instead of working more on that Barber (which seems to be a fine piece of steel...) why not try "authenticating" the scales. Copy some of the ideas from so many of the old razors that wind up at my house: Scratch your name delicately and deep in the scales with some pointed thing, can be jaggedly pointed. If your name seems like a bit too much personalization, just scratch some random letters or symbols.

Also you can forgo the pins and use the wonderfully efficient method of "any old nail". Choosing a rusty one to begin with will provide extra charm with no waiting. To compliment the refined elegance of "any old nail", square cut some pieces of somewhat thin/thick copper or brass sheeting to use as washers. Don't worry about cutting them too large, just hammer them over the sides of the scales afterwards...

Voila! Flash begone!:
(Of course, these extra steps would have been unnecessary if you had gone with the "any old stick" method of scale making. Only tool required is a pocket knife... )

regards,
Torolf

 

[Matt]

mwahahhahaha

Try electrical tape instead of masking tape. It is much more wear resistant.:thumbup:

Once it happened to me that I ripped the outermost layer off of old scales using electrical tape. Masking tape has weaker glue. :thumbup:

I think the white material may be the resin paper that knife makers use.

That's exactly what I suspected it to be.

cheers,
Matt

 

[TM280]

I have to remember that about the tape. Thanks for mentioning it.

What are you cutting with? Do you think this paper is epoxy impregnated?

regards,
Torolf

 

[Matt]

I was cutting it with a Dremel using an ordinary cutting disc (the brittle one, pt. # 409) but if was to cut it on a regular basis, I would get those fiberglass reinforced, or maybe even a diamond cutting wheel. That was an absolute pain in the ass, plus the epoxy spillover.

As I said, yes, I suspect this stuff is resin impregnated. The sheets Ray has sent me are 0.8 mm thick, but it looks like it could be even half of that and still maintain its durability. Whether it's epoxy or other kind, I have no idea.

cheers,
Matt

 

[Matt]

Okay, so judging by the looks (especially the torn edges with tiny shreds that look like paper but are impossible to remove with bare hands), it's most probably this. Too bad I haven't landed there earlier, I'd sand it before I glued it to the scales, ehhh. Nice tip to seal the thing with CA though, I would never think it might be slightly hygroscopic.

Oh, there's another homegrown tip - I decided to go for fitting a brass tube inside a razor pin hole. But instead of gluing it in with epoxy I chose a simpler and lazier route - I sanded the sides of the tube so that the were nearly fitting snugly into the hole, and then I just hammered it in. Sits perfectly, of course it got a little deformed, so the pin wouldn't go through, but then you just put a drill through and it's fixed in a second. The tube sits in hard enough not to start rotating together when you're re-drilling through. :thumbup:

Oh and also be sure to crank up RPM when cutting, or drilling through horn with a Dremel (actually, this applies to the damn impregnated paper too, I was cutting it at 6 or 8 setting, which corresponds to 20K - 30K RPM). The 1.2 mm drill I used for a pre-drill stopped and got caught into the wedge and I had a hard time removing it without breaking. Unfortunately, Dremel is a high-speed low-torque device, so low RPM won't always work and these materials are really dense.

cheers,
Matt

 

[macrob]

Why guerilla? Well, I have no other tools than Dremel, some cutting/sanding/buffing wheels, a file, sanding papers, pastes and that would be all. Not much like serious restorers' workshops (while we're on it, I don't have any of that kind, either ).

Welcome on-board Matt.I'm in the same situation. But remember , our hands are our best tools.

Good luck with your project.

 

[Matt]

Well, seeing your work puts my skills in proper perspective compared to yours... :

BTW today I found out about a RotoCut tool, by Bosch. Looking at it I believe this thing is much more suited for things we do. And you get this cool vertical attachment in the box instead of paying a lot for a Dremel extension... I wish I had known earlier about this.

cheers,
Matt

 

[Emmanuel]

Matt .I think that you do your life difficult without a special reason. If i understood well you cut peripherally the white sheet by a dremel disk ? And now you think about the rotocut.Surely you don't need it my friend .You need just manual tools for fine works like razor scales etc. I suggest
a copy saw like the mine:

You just design on the material by a pencil what exactly you need to cut and you cut it peripherally following the line without any fracture because the microteeth do not allow.
Best regards
Emmanuel

 

[macrob]

I agree with that in 100%. I am using hand tools myself and i realy enjoy it.

 

[Matt]

I was actually thinking if I could go faster manually... : I'm sometimes good at making things more complicated, than needed.

You are right, thank you.

 

[Matt]

Since I recently started to do some restorations I was wondering about omnipresent belief about superiority of stationary buffers versus an ordinary Dremel. The alleged main advantage of the former is its lower RPM, which obviously allows the buffing wheel to run slower, hence limiting the possibility of damaging the blade. Is it really so?

The restored razor has no clue at what RPM you're running your tool. The final thing that matters is how fast the steel is abraded, hence - the linear velocity at the edge of the wheel. That, of course, is the function of angular speed, i.e. RPM, but of the diameter of the wheel as well.

I don't know the exact diameter of the stationary buffing wheel, but looking at the pictures, estimating it to about 25 cm sounds reasonable. Besides, this will make comparison much easier, because 2,5 cm is the diameter of the hard felt wheels I work with (the bigger ones, as there are also smaller, 1,5 cm ones). Let's make d[sub]b[/sub] the diameter of the big wheel, d[sub]s[/sub] - the diameter of the small wheel. I remember from Ralfy's post that he runs his rotary tool at 800 RPM, which is pretty close to 1k. A Dremel, at its lower setting, runs at about 10k.

Let's do some simple basic maths here. Circumference of the wheel is π×d, linear velocity at its edge is simply RPM multiplied by its circumference (a single rotation goes a one full circumference buffed against the blade): v=π×d×RPM.

On to the real numbers (I'll make dimensions in meters for smaller numbers):

d[sub]b[/sub]=0.25 m
RPM[sub]b[/sub]=1000 min[sup]-1[/sup]

d[sub]s[/sub]=0.025 m
RPM[sub]s[/sub]=10000 min[sup]-1[/sup]

v[sub]b[/sub]=π×d[sub]b[/sub]×RPM[sub]b[/sub]
v[sub]b[/sub]=3.1416×0.25×1000
v[sub]b[/sub]=785.4 m/min

v[sub]s[/sub]=π×d[sub]s[/sub]×RPM[sub]s[/sub]
v[sub]s[/sub]=3.1416×0.025×10000
v[sub]s[/sub]=785.4 m/min

Surprise, the numbers are the same! Π is a constant, so linear velocity is only the function of product of RPM and diameter. Make one greater 10 times, another smaller 10 times and you get the same thing. The same effect on the blade.

Surely, there have been some approximations, as I said, I don't know the exact buffing wheels' diameter, RPM may vary a bit. Anyway, you get the picture - these speeds are in pretty similar range. Some buffers probably can also run at lower speeds. But then, you can always take a 1,5 cm felt wheel (that's 60% of the 2,5 cm one) for your Dremel...

regards,
Matt

 

[tat2Ralfy]

If it helps, I use 100mm discs in my pillar drill which I run at something like 2000 rpm, I judge heat of the blade by not wearing gloves, hardened steel is heat sensitive, but not as sensitive as my hands lol

Oh and nice work on the razor btw :thumbup:

Best regards
Ralfson (Dr)

 

[Matt]

Well in this case it gives 3.1416×0.1×2000=628.32 m/min. Pretty similar. Dremel with a 15 mm felt disc at 10k goes only at 471.24

As far as the razor, the blade in those scales is in the same condition as on the original pictures. I recently managed to do a decent restoration of this blade - thank you Maciek for the tips on proper paper/pastes order - and that gave me some courage. I hit a John Boker with 180 grit paper today, but boy, there still will be a lot of pitting. But I don't want to go for NOS-like looks anyway, besides it would require removal of ridiculous amount of valuable old steel.

cheers,
Matt

 

[vgeorge]

I would think it is a bit more complicated than RPM and diameter.

Temperature goes up based on heat retained, which would be heat added by friction minus heat removed by radiation, conduction, etc.

Everything else remaining the same, if you increase RPM, surely temperature will go up. Area of contact, coefficient of friction, etc. also would independently matter, I would think.

Watching the temperature is the smart thing to do, as the good doc does.

 

[Smythe]

I don't use buffers to restore razors so you may take my comments with a grain of salt...

The blade is light and is relativity easy to manipulate with both hands, so when using a stationary buffing machine it is easy to achieve a light (delicate) touch.

On the other hand, Though the blade would be secured in a stationary holder (really bad idea holding Dremmel in one hand, and blade in the other) the Dremmel is relatively heavy compared to the blade, and if a light touch is needed, there is little feedback.

 

[Matt]

Cedrick, what do you use for your restores then, if I may ask? I find it hard to believe that your (tremendous, in fact) works are only manual?

 

[Matt]

I would think it is a bit more complicated than RPM and diameter.

Temperature goes up based on heat retained, which would be heat added by friction minus heat removed by radiation, conduction, etc.

Everything else remaining the same, if you increase RPM, surely temperature will go up. Area of contact, coefficient of friction, etc. also would independently matter, I would think.

I'm sorry, but as smart as it sounds - what is the point, exactly? You mean there's a significant difference coming from a larger area surface of a bigger wheel? Coefficient of friction may vary between various wheels, so I'd take that out of the equation. Radiation and conduction aren't dependant on parameters discussed either, as I see it...

regards,
Matt

 

[Emmanuel]

My friends Here is my suggestions : If i understood well the only problem is just the temperature which is unsafe for the blade hardness.The key isn't to reduce the rpm but is to exclude the temperature.First ,personally i use a flexible shaft ( dremel accessory). It is more lighter,is narrower and finally is more easy to manipulate.I fix the blade on a large metal block ,i prefer aluminum as more conductive ,by a clamp , clamping the shank. By this way you can work on the blade without any worry for overheating. I have counted several times the temperature on the edge by a laser thermometer and never surpassed the temperature of 38 Celsius.Note that the the edge and the spine touch completely on the aluminum block.

Best regards
Emmanuel

 

[Matt]

Fantastic. :thumbup: I was actually wondering if anyone had ever measured a blade's temperature during buffing... Great tip about the metal block, thank you Emmanuel.

regards,
Matt