Repairing and refurbishing 91's

[Jim the Brave]

I've been wondering about just how difficult/expensive it is to refurbish, rebuild, and repair 91mm Vics. With the press-on scales and riveted construction, they're not designed to be easily disassembled. I would hate to have to buy new scales every time I wanted to take one apart. Kind of defeats the purpose, if the scales are in good shape, but a blade breaks, for instance.

Maybe there's already a thread about all this. If so, if anyone wants to redirect me, have at it. :-)

So a few questions:

1. Is it possible to reuse the existing scales if you take them off?
2. How do you disassemble and reassemble the metal parts of the knife after the scales are off?
3. Are there any ways to buy new scales at a reasonable price?
4. Other than donor knives, what options are available for getting replacement parts?
5. What options might there be for aftermarket parts, including special tools?
6. If you make your own wooden scales, how do you get them to attach?
7. Is awl this really worth it, or just get a new knife?

[Jolt_159]

To answer Q1, if you take out T&T fron the scales, soak in boiling water for 1 minute and then take them off, they can often be re-used.

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[Jim the Brave]

To answer Q1, if you take out T&T fron the scales, soak in boiling water for 1 minute and then take them off, they can often be re-used.

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Ah, nice. So does the knife (obviously, the plastic scales) need to be still hot when you get them off?

[Jolt_159]

Ah, nice. So does the knife (obviously, the plastic scales) need to be still hot when you get them off?

Yes immediately after you take the knife out take the scales off.

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[Nix]

Carefully! 

[Nix]

I haven't had great success breaking a SAK down to individual parts. (some of the guys here on the forum are quite expert at this.)

However, I have taken some ill-used and dirty SAKs and just rehabilitated them by cleaning them (scales on for one dreadful SAK) vigorously in hot soapy water.

Hot soapy water and a toothbrush (don't use your own toothbrush--d'uh!--I borrow Mrs Nix's) will work miracles for a nasty old SAK. After awl that hot water and soap.....oil. The SAK will feel gritty and stiff until it gets a little love and care in the form of some oil. Mineral oil or Ballistol are my go-to lubricants, but a SAK will be grateful for any sort of oil, really.

[Jolt_159]

Ah, nice. So does the knife (obviously, the plastic scales) need to be still hot when you get them off?

 There is a link to the video. Skip about 3 mins in

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[Jim the Brave]

 There is a link to the video. Skip about 3 mins in

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Ah thanks!

[kamakiri]

I've been wondering about just how difficult/expensive it is to refurbish, rebuild, and repair 91mm Vics. With the press-on scales and riveted construction, they're not designed to be easily disassembled. I would hate to have to buy new scales every time I wanted to take one apart. Kind of defeats the purpose, if the scales are in good shape, but a blade breaks, for instance.

Maybe there's already a thread about all this. If so, if anyone wants to redirect me, have at it. :-)

Lots of threads! But I’ll start with some rough answers below.

So a few questions:

1. Is it possible to reuse the existing scales if you take them off?

Yes. Heat is usually better for reuse. I don’t use water.

2. How do you disassemble and reassemble the metal parts of the knife after the scales are off?

Lots of threads on this in the mod sub forum. But the main part is drilling out the existing rivet/pins and re-riveting (or using screws in some types of modifications) for reassembly.

3. Are there any ways to buy new scales at a reasonable price?

Lots. *bay is where I’d go for most.

4. Other than donor knives, what options are available for getting replacement parts?

A few sellers have loose parts available. Often without the needed backsprings. So more for simple part replacement, typically.  But my main source are donor knives.

5. What options might there be for aftermarket parts, including special tools?

I suppose some of the well known moderates who fabricate their own parts could be a source. But no idea, as I do mostly restoration type work and pretty light on the fabrication.

6. If you make your own wooden scales, how do you get them to attach?

I’ve mostly seen adhesives used for wood scales, but that’s just observation.

7. Is awl this really worth it, or just get a new knife?

Worth it to me for vintage stuff. Also for creating knives that would never be made otherwise. Users of ‘rare’ models are also a good reason. Like if I really wanted a ‘scientist’...I’d just build it.

[kamakiri]

Sub forum is here:
The Mod Squad
Good luck!

[Echotech]

Hot soapy water and a toothbrush (don't use your own toothbrush--d'uh!--I borrow Mrs Nix's)…

[Jim the Brave]

Thanks, guys!

[Helvetica Bold]

It’s quite addictive if/when you start modding or creating or reproducing new/discontinued models. If you want to put  celador handles back on you are best off being very careful not to damage the little brass collars that he handles push on to as they are very difficult to find or make. Otherwise not a problem if you are going to use screws or glue.

[Jim the Brave]

And I also wonder if there's any real way to sharpen the saw blades.....

[kamakiri]

And I also wonder if there's any real way to sharpen the saw blades.....

I’ve used the triangle stones from the Spyderco Sharpmaker for the wood saws. Since it’s double -cut, I do every other tooth (gap) in one direction. Then do all the missed ones in a second pass. Just try to keep the pressure and number of strokes consistent.

[Jim the Brave]

I was wondering if there were some triangular device that could do it. That's encouraging.

[Helvetica Bold]

Depends how bad it is blunted. A fine square mini diamond file will probably be best for re-shaping if it’s really bad -might even get it sharp enough but the corner to a small sharpening stone should work for the final touch if not.

[kamakiri]

Depends how bad it is blunted. A fine square mini diamond file will probably be best for re-shaping if it’s really bad -might even get it sharp enough but the corner to a small sharpening stone should work for the final touch if not.

I dunno. I’ve used diamond files and it’s not easier and hard to say ‘best’ even for very worn tips. Consistency matters most, IMO for making all the teeth usable.

[Helvetica Bold]

Fair enough ‘best’ might be an ambiguous term ;0) I didn’t think he wants to buy a Sharpmaker though so maybe an adequate alternative.

[kamakiri]

 

The Sharpmaker rods can be purchased separately from the kit, or in pairs.

My main issue with the diamond files I tried is that they are short. And that lack of length makes it difficult to maintain consistent angles and pressure. Files also cut only one face at a time while the triangle stones ‘self-center’ and self-align while cutting two faces at a time. 

[Jim the Brave]

The Sharpmaker rods can be purchased separately from the kit, or in pairs.

My main issue with the diamond files I tried is that they are short. And that lack of length makes it difficult to maintain consistent angles and pressure. Files also cut only one face at a time while the triangle stones ‘self-center’ and self-align while cutting two faces at a time.

Um...yes. I assume that is only if the angle of the triangle stone matches the angle of the teeth.... 

[Jim the Brave]

Now I'm starting to wonder if there's a good way to touch up old dull-looking celidor scales. Some kind of turtle wax or something? Just trying to figure it out....

Naturally, if I can get old dull scales to look better, I'll be better able to sell the used knives I get in the wholesale batches.

[SAKTaschenmesser]

Now I'm starting to wonder if there's a good way to touch up old dull-looking celidor scales. Some kind of turtle wax or something? Just trying to figure it out....

Naturally, if I can get old dull scales to look better, I'll be better able to sell the used knives I get in the wholesale batches.

Maybe try Polywatch? Used to polish acrylic watch lenses. Toothpaste is used as an alternative.

Finish with a bit of chopping board food grade wax?

Worth a try on one knife.


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[Don Pablo]

I heard some people use Brasso.

[Rizio Il Ghiro]

Brasso works well for polishing plastics, works like jewellers’ rouge. We used to use it in plastics class at school in the late 1970s, and it’s still my go to polish for copper, brass and plastic. Might not be easy to come by where you are though....

[SAKTaschenmesser]

I’ve also used Peek.

https://tripeek.com

I liked this endorsement 'By Appointment to Her Majesty The Queen, Purveyors of Metal Polish, Tri-Peek International Limited Saffron Walden'.

If it's good enough for her collection of crowns and jewels, it's good enough for my collection of SAKs.

Doesn’t Brasso have quite a lot of Petrol in it? Used in many times with metal, but it doesn’t discolour the red plastic scales does it?


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[Rizio Il Ghiro]

It’s a mild (but smelly!) solvent rather than petrol, and I’ve not had it discolour any plastic I’ve used it on, but it would be wise to test it first if you’re not sure on a small piece first.

[Jim the Brave]

Thanks, y'all, I'll try one or more of these products.

[kamakiri]

Um...yes. I assume that is only if the angle of the triangle stone matches the angle of the teeth.... 

Close enough for me.

Now I'm starting to wonder if there's a good way to touch up old dull-looking celidor scales. Some kind of turtle wax or something? Just trying to figure it out....

Naturally, if I can get old dull scales to look better, I'll be better able to sell the used knives I get in the wholesale batches.

I’d try ‘micromesh’ abrasives first.