Bolster-scale alignment

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Jun 3, 2017
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With the help of this forum, i have greatly stepped up the functional quality of my slip joint folders. I have two design templates that I'm using now and am able to reproduce slip joints that work well and look good.

This leaves me with my last hurdle, fitting bolsters properly. I struggle with aligning them correctly on both the belly and the spine of the handle. I have tried two methods:

1) put both liners together and scribe a line on each liner. It's pretty easy to get these lines to have endpoints that match since you're holding liners together. The lines show the bolster-scale transition line. The main problem i have here is that the epoxy that squeezes out obscures the line, and I can't really tell if I'm hitting that line exactly when i go to clamp.

2) glue one side together, doesn't really matter how. Then after it dries, i glue the other side and lightly clamp it, then slide it around a bit while holding the other glued up handle side up against it and fiddling with it until it looks like it will match, then tighten the clamps down. The clamps always move the piece and i get misalignment, or just the inherent inaccuracy of this method makes it not work well.

So I don't know. Any tricks to getting this right? Maybe just don't get epoxy near the edge so it won't squeeze out in method 1? It would work, but is there a better way?

Here is a pic to show what i mean by misalignment.
lWJ9jRH.jpg
 
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I don't see Bolsters only misaligned scales?

Before fitting the scales the Liners and Bolsters should be totally finished. Bolsters should be fully attached and the backs of the bolsters square to each other. Once the bolsters are secure then you can butt the scales tight to the bolster for perfect alignment.
Do a google search on Tony Bose videos Bolster fitting. He is one of the best slip joint knife makers with good tutorials.
 
Well, bolsters misaligned = scales misaligned. Here i put the scales on first so i could try to rasp them even. I just watched the tony bose 4 part video on soldering bolsters. Not much specifics there.

I guess I'll learn how to solder. I've never done it before. And then rig up an extra piece for my templates to align the bolsters when soldering. I can see how that could work well if i use the pin holes to set up the aligning template piece. I'll remember the pencil lead trick mentioned in the videos.

I guess i can use this extra template piece when fitting the bolsters? Cut out a basic bolster shape, drill pivot hole, clamp it all together, then file the bolster to the liner. Then I'd be ready to solder i guess.
 
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Do you have a filing jig? Put jig where you want scales to go and slide them up. I don't use epoxy on scales. Heat generated curing can cause trouble. Use super glue for better appearance.
 
When you watched the video did you notice that Tony uses a piece of 1/8" flat stock with a center notch filed to square up the bolsters top/bottom with liners spine and belly then marks his line with pencil lead so the solder won't flow where the scale meets the back of the bolster. You have to use the Pivot Pin to set the bolster and make the alignment precise with the line if you are going to do a glue job. I've done over a hundred slip joints with the solder method the only easier way is a spot welder. Epoxy is not a secure long term method of holding a bolster in place.
 
Oh gosh.

Put your bolsters on first. The method I use, which is fool-proof for alignment if done correctly, for the bolsters, is to simply take a scrap piece of micarta, around the size of your scales, but rectangular, clamp it to the liner where it looks right, leaving the area for your bolster exposed. I just "adjust" by eye. When the area you've left un-covered by the piece of micarta (or whatever) looks right, i.e. how you want your bolster to look, drill the two spring pin holes through the micarta, while it's still clamped. Do this accurately, as you would anything while making folders, and stick a couple of temp pins in there.

Now you've got a template, all you have to do, is butt the oversized bolster material up tight to the square edge of the micarta, clamp, and then spot weld, solder, glue, whatever you're gonna do. Flip it over on your other liner, and repeat. Assuming your liners are accurate to each other, then your bolsters will be also.

Of course, all this requires you to have your liners roughly shaped, and your primary pin holes in place in the liners already.

I use the same piece of micarta until there are too many holes for me to keep track of even marking them each time with a sharpie.


If this doesn't make sense, I can take a photo, but even if you're gluing up micarta bolsters, I'd always do the bolsters first, and the scales last.

Temporary pins and temporary fixturing (a drop of superglue) are something I recommend training yourself to utilize making slipjoints. Yes, you can glue on handle material at the beginning before you clock or finish anything, but that methodology has severe limitations when you start wanting to work with materials that require everything to be finished separately. On a mono steel knife without any fancy fittings or embellishments, you can pin and glue everything together rough, and even grind your blade last, but you're not going to be able to do that with damascus, or domed pins, or fancy bolsters, etc, and if you screw something up, you may have to simply start over.

I build every piece independently, finish each component, and typically the last thing I do is glue the handle material, then pin the whole thing together, and it's done. If I screw any single piece up, no problem, just replace it.
 
Javand, yeah i like the idea of making an additional piece for the template that aligns the bolsters like you described. After reading my second post again, that's what i had planned to do, i just didn't describe it well.

I agree epoxy is bad. I have had the bolsters pop off during light filing. I like the idea of using solder, i just need to practice with it. I also like the idea of fitting everything before assembly. I had some troubles when i first started making slip joints, and i started doing incremental builds so i could correct issues as they come up. This is bad, i know, and that's one reason i joined this forum.

I thought i could wing it with slip joints, but i have found the process, accuracy, and proper techinques are essential. I want to build them in a proper way.
 
The right solder and right flux is key. I don't do much in the way of soldered bolsters, but I do plenty of soldered guards.
The first thing is your heat source. You want something to get it hot fast. A propane torch will generally start burning the flux out of parts before getting the whole part up to temperature. A Mapp gas torch will work, and I used one for a while. Currently I use a turbo torch air acetylene setup, and it does a very good job. Oxy acetylene is nice to work with, but I generally don't bother using it unless brazing.

As for flux, plumbing flux generally won't cut it. I use ruby fluid (the stainless formulation in particular) but Harris stay clean is equivalent.
Solder wise you have two options. Tin/lead solder, or soft silver solder (Harris stay bright, ect) the "silver bearing" lead free solder sold in the plumbing section generally doesn't work for shit.
Lead solder is cheap, but you have to be mindful of the dust when sanding and polishing. Silver solder is really the way to go.
A welding supplier such as Airgas/Andir Liquide or Praxair/Linde will sell a kit with a small bottle of liquid flux and a small roll of soft silver solder for $20-30. And that will solder a lot of guards and bolsters.

Clean clean clean is the other thing. I always degrease everything with acetone and scuff with a clean piece of scotchbright before soldering.
Sometimes it can be helpful to individually tin the different pieces before assembly, but that isn't always necessary

Its just something that takes practice. I'd recommend getting some sheet metal (just mild steel works) and practice soldering pieces of it together until you get a feel for heat control and when and how much to apply solder. Practicing on knives is generally not the most economical approach
 
It currently takes me about 20 hours to complete a knife. I use all hand tools except a drill. I definitely won't be practicing on a knife! I have plenty of junk steel laying around. Thanks for the help guys.
 
Javand, yeah i like the idea of making an additional piece for the template that aligns the bolsters like you described. After reading my second post again, that's what i had planned to do, i just didn't describe it well.

I agree epoxy is bad. I have had the bolsters pop off during light filing. I like the idea of using solder, i just need to practice with it. I also like the idea of fitting everything before assembly. I had some troubles when i first started making slip joints, and i started doing incremental builds so i could correct issues as they come up. This is bad, i know, and that's one reason i joined this forum.

I thought i could wing it with slip joints, but i have found the process, accuracy, and proper techinques are essential. I want to build them in a proper way.


They're the most deceptively simple seeming, yet complex folding mechanism there is. I contend that they're the most nuanced, and ultimately, the most complicated of all folding knife styles. I personally feel that this is a big reason why they're timeless, as a fundamental type of knife. Even though the market ebbs and flows, slipjoints have always maintained a steady respect and demand.

Though other more modern mechanism are "technically" superior in many ways, the relationship between, even complex components, don't require the critical accuracy, nor do they showcase the maker's skill at the relationships of those critical interactions, the way a slipjoint does, in so many subtle ways.

That's part of what keeps me transfixed on them, even though I had no interest in folding knives when I began in this trade, and even well after. Once I made my first, I was hooked, to the point it's nearly impossible to talk me into making fixed blades anymore.


It's not very difficult to make a crap slipjoint, but making a good, let alone a great one, takes massive amounts of skill and patience. Of course, you won't know what makes a great one, until you've handled one.


If you need any help, don't hesitate to ask.
 
I'd definitely be inclined to agree with that. I've nearly finished my first liner lock (just finishing the blade left) and it was surprisingly easy.
On the other hand I have 4 or 5 half completed slipjoints laying around, none of which I'm actually happy enough with to finish. I think I finally have all the bugs worked out though...
 
Small slip joint pocket knives are a great learning tool for patience when working out lock geometry, but if you maser the design they are quite simple compared to the lock design of "Lockbacks"....ooof!!!
 
Small slip joint pocket knives are a great learning tool for patience when working out lock geometry, but if you maser the design they are quite simple compared to the lock design of "Lockbacks"....ooof!!!

We'll have to agree to disagree. I could go on and on as to why I feel lock-backs are much simpler, and easier to reproduce in numbers, but I'm guessing we won't see eye to eye about it regardless, so I won't bother. ;)

To each their own.
 
Thought I'd add a pic of the final knife. When the light shines on the bolster you can see the bolster pin shadow. The bolsters are uneven, but those two things are about the only real flaws. I always leave the metal a little rough, i just really like that rough look. I don't sell my knives, i just give them away, and most people i know like the rough look too.

hDbKsZw.jpg


Orderes the solder and it should be here sometime this week. I've been reading and watching a lot about soldering. We'll see how it goes.
 
There ya go...the more you make the better they get you understand the issues with the previous models and don't repeat those mistakes. Try to make every knife
better than the last. I make every knife as perfect as possible I have high standards and the person receiving the knife should not see any imperfections. That is a sense of pride in workmanship and a sense of pride in ownership.
 
So i tried soldering two scrap pieces together.
sX1DflK.jpg

UOrLqfr.jpg


My torch gets hot real fast, about 2 seconds of continuous flame and it's melted. I need to do quick passes until it just melts. I also underestimated the amount of wire i need to use. I think i burnt the brass, it's pretty discolored, I don't think it'll sand out....

The joint is really solid! I think i just need to be careful with the heat. And i need more practice.
 
That brass may clean up actually. What you want to check is the joint around the liner and bolster you will have to file or grind to get to clean metal to inspect the joint. Watch the video again and watch how little direct flame is used Tony just moves the flame close and away until the solder starts to flow then removes the flame completely. You will get the hang of it just practice and patience...:thumbsup:
 
I melted that piece off and tried again. This time i used too much wire, i got a puddle that ran away from me. I feel like goldilocks! Turns out i can sand it a bit and get it to clean up. A few more times and I'll be good to go i hope.

Y4hltwm.jpg
 
You'll get the hang of it soon enough! It took me a while to get decent at it. The world opens up once you get the hang of soft soldering though. Suddenly guards on hidden tangs become world's easier to fit. Of course you always want the best fit possible, but knowing how to make gaps disappear can be helpful at times
 
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