Recommendation? Attaching Brass Guards - Current Thoughts?

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Cushing H.

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I am continuing to plan out the design for that skinner I making - and currently am planning on a brass guard. For attaching bolsters and guards, Boye had taught either brazing or soldering. I have been working on my soldering capability - and dont have any concerns about being to execute that on this knife. In addition, with a single-sided guard (long slit from one side, other side solid brass protruding from the bottom of the knife), soldering seems the only practical way of attaching it.

On the other hand, current examples on the forum, and a number of video examples out there (including Walter Sorrells) seem to really focus on pinning and peening for bolsters (and maybe adding epoxy, which surprises me) - but like I said, this seems impractical for a slitted guard (due to difficulties in getting the pin holes to line up.). Much on the previous threads on the forum on this topic are quite a few years old - what is the current wisdom of the group on how to attach single sided guards???
 
I don't know if anything has changed much lately but for what it's worth I like to solder my guards in place.
 
the epoxy is most likely to keep moisture and corrosion out of the joint, rather than add strength on a pinned bolster or guard. as far as getting the holes to line up i would fit the guard and drill the guard and blade at the same time pre heat treat in a drill press vise. you can clamp the guard with needle nosed vise grips while drilling. bob loveless would both pin/peen and solder, that is how i do most of mine.
 
john april said:
the epoxy is most likely to keep moisture and corrosion out of the joint, rather than add strength on a pinned bolster or guard. as far as getting the holes to line up i would fit the guard and drill the guard and blade at the same time pre heat treat in a drill press vise. you can clamp the guard with needle nosed vise grips while drilling. bob loveless would both pin/peen and solder, that is how i do most of mine.
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good idea for drilling all pre- HT. Right now I am planning on the guard being only 1/4" wide (front to back) (either made by me, or purchased from Jantz... ... kind of a tight fit for 1/8" pins - is 1/16" ok for bolster pins? Looks like my local hardware store has that in rod stock....

I did see the pin/solder recommendation online. first it struck me as duplicative - but I do see the advantage of pinning and forming pre-attachment. A little scary though - if you do something to mess up that pre-drilled guard, you are back to figuring out how to make the holes line up when you go to create the "replacement" guard......
 
Scott Hanson said:
I don't know if anything has changed much lately but for what it's worth I like to solder my guards in place.
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Scott - at least one person online commented that solder is not for structural strength, but for water exclusion (not my expectation - a well executed solder joint "should" be pretty darned strong). What is your experience with the structural integrity of solder-only joints??
 
Cushing H. said:
good idea for drilling all pre- HT. Right now I am planning on the guard being only 1/4" wide (front to back) (either made by me, or purchased from Jantz... ... kind of a tight fit for 1/8" pins - is 1/16" ok for bolster pins? Looks like my local hardware store has that in rod stock....

I did see the pin/solder recommendation online. first it struck me as duplicative - but I do see the advantage of pinning and forming pre-attachment. A little scary though - if you do something to mess up that pre-drilled guard, you are back to figuring out how to make the holes line up when you go to create the "replacement" guard......
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Pops has pin stock to go with their bar stock if you are getting belts.

I have heard that the downside of solder is if done wrong the flux can cause problems later on.
 
A good joint with low temperature silver-bearing (4%) solder is entirely adequate for keeping a guard in place. If residual soldering flux is not removed, it can cause corrosion-but it's simple to remove.
Pinning adds extra insurance.
 
Cushing H. said:
Scott - at least one person online commented that solder is not for structural strength, but for water exclusion (not my expectation - a well executed solder joint "should" be pretty darned strong). What is your experience with the structural integrity of solder-only joints??
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Tensile strength of Stay-brite solder is 14,000 psi while J-B weld is about 4,000 psi. In the 30 or so years I've been making knives I have never had a solder joint fail, a soldered guard should be sufficiently strong for just about any knife.
 
Scott Hanson said:
Tensile strength of Stay-brite solder is 14,000 psi while J-B weld is about 4,000 psi. In the 30 or so years I've been making knives I have never had a solder joint fail, a soldered guard should be sufficiently strong for just about any knife.
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I did not know the numbers, but something like that would be my expectation. I was quite pleasantly surprised at how reasonable it was to execute without overheating the blade (even with a really small blade), especially if wrapping with a wet cloth. Im surprised more people dont solder? Definitely need to know the difference between a good joint and a cold joint - but with all that brass as a thermal mass it seems difficult to create to create a cold joint in the first place...
 
i use 3/32" for pins through the guard. with the 1/16" i am always scared the drill bit will break off in there with the guard stock being 3/4" wide with the cpm-154 in the middle. as far as structural integrity, i bet it would be very hard if not impossible to remove a soldered-only guard with a hammer.
 
john april said:
i use 3/32" for pins through the guard. with the 1/16" i am always scared the drill bit will break off in there with the guard stock being 3/4" wide with the cpm-154 in the middle. as far as structural integrity, i bet it would be very hard if not impossible to remove a soldered-only guard with a hammer.
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I actually have removed a couple guards from blades that were soldered on when I was first learning how to solder. I ended up heating them up until the solder melted and got them off that way. I think I tried hitting one with a hammer but that didn't seem to work to well.
 
"...I was quite pleasantly surprised at how reasonable it was to execute without overheating the blade (even with a really small blade), especially if wrapping with a wet cloth. …"

There is no reason that the blade needs to be wrapped in a wert cloth to properly solder a guard on (but it won't hurt anything). The solder melts at 400F or less. You don't need a lot of heat to melt it - actually, high heat will make the joint fail. A very small torch or a heat gun will make perfect solder joints and will not affect the temper at all. I regularly flow the solder on the guard while holding the blade in my hand.

A $15 refillable butane torch is perfect for soldering guards.
 
I have successfully soldered guards and almost exclusively. I have found that clean surfaces the correct flux, a tight fitting slot will make a very strong joint. If soldered properly and sufficient solder is used, the solder should completely fill the joint leaving no flux behind. the guard and blade should be hot enough to melt the solder which allows it to flow throughout the joint.

The only issue I have had with pining guards is finding matching alloys of pinning material and guard material. I find that if they are not they show up differently when finished and can be less attractive.
 
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