Okay, I suck at soldering, but...

t1mpani · Mar 25, 2017

Unable to find a 3/4" by 1.5" piece of nickel silver, I have two 3/8" thick pieces that are inletted and going to be sandwhiched over a tang to make a pommel. Currently, they're not fully cut to shape (and I know I would need to complete that step before attempting to join them) but I wanted to go ahead and get my solder ordered. While I'd originally intended to just get a good tight fit and rough up the interiors for epoxy, I'm thinking it'd be stronger and more seamless if the pieces were soldered together.

The ONLY soldering I've ever done is electrical, and I wanted to present my intentions here and see what you think.
1) The pommel is NOT going to be soldered to the tang, but joined via epoxy and corby bolt behind a drilled wooden handle, so no need to worry about a joint with steel
2) I assume I'm going to need a low temp solder for nickel silver--exactly which one (and which flux) I'm not sure of but figured one of you might be

3) My thought was to get a piece of wood sized perfectly to be a hard press-fit into the channels which will keep the pieces aligned properly with each other, and make it long enough to clamp the wood in my vise and have the nickel up in the air where I can get to all sides with a heat gun, and then use a c-clamp with a couple of pieces of scrap g10 or micarta pressing on the outside to to keep things tight, without any kind of metal touching the nickel and pulling heat away from it

So, if both halves are sanded to a 220 grit finish and it's a good tight fit, will the solder get a deep enough penetration all the way around to get a good joint? Any tips, tricks, better ways to go at it would be hugely appreciated.

Warren

Bill DeShivs · Mar 25, 2017

OK-
I would use hard solder, as the joint would be less visible.

If you want low temperature solder, use common, silver-bearing (4%) solder from any hardware store.
The best flux is Stay Clean liquid flux.
Your idea of using a piece of wood won't work-the wood will burn. Use thin wire to wrap the pieces together.
Place the part on a heat-reflecting surface like firebrick or a charcoal block.
Make sure the inside of the joint is clean-file/sand it bright immediately before soldering.
Flux, then wrap with wire. Wash your hands to remove flux.
Heat until the solder flows when touched to the joint. Solder flows toward heat. Use just enough to see a visible line of solder in the joint.

mete · Mar 25, 2017

The low temp 'silver solders' are about 96% Sn, and 40% Ag. Melts at about 450 F. Heat the part to temper then touch the solder to the part .Max strength for soldered and brazed joints is .003 " which is also the best for capillary action to flow into the joint.

t1mpani · Mar 25, 2017

Thanks to both of you!

Bill DeShivs said:
OK-
I would use hard solder, as the joint would be less visible.

If you want low temperature solder, use common, silver-bearing (4%) solder from any hardware store.
The best flux is Stay Clean liquid flux.
Your idea of using a piece of wood won't work-the wood will burn. Use thin wire to wrap the pieces together.
Place the part on a heat-reflecting surface like firebrick or a charcoal block.
Make sure the inside of the joint is clean-file/sand it bright immediately before soldering.
Flux, then wrap with wire. Wash your hands to remove flux.
Heat until the solder flows when touched to the joint. Solder flows toward heat. Use just enough to see a visible line of solder in the joint.

Using a hard solder would require the purchase of a torch, as I don't think my heatgun will get it.
Hmmmm (on the wire wrapping). I'm sure you're absolutely correct, I just wish there was a way to keep the channels lined up perfectly because otherwise the tang will not go in. Dammit, I just KNEW this wasn't going to be simple...

I wonder if I was able to do some hidden pins--drill one side, insert a piece of pointed drill rod and then use my piece of wood idea to keep the channels aligned while gently tapping the halves together, and then drilling the hopefully-center-punched holes on the other side. Then I can just insert 1/8" nickel rod pieces for alignment and then wrap with wire.

mete said:
The low temp 'silver solders' are about 96% Sn, and 40% Ag. Melts at about 450 F. Heat the part to temper then touch the solder to the part .Max strength for soldered and brazed joints is .003 " which is also the best for capillary action to flow into the joint.

So if the industry standard measurement is correct that typical 220 grit paper is making 60 micron scratches and 150 grit is 80 micron, and I'm aiming for .003" (76 micron) separation then perhaps I should sand the mating surfaces at 180 grit, or do you mean they shouldn't be quite touching at all?
I apologize for being dense

Bill DeShivs · Mar 25, 2017

You could just pin the halves together.
Drill, insert nickel silver rod, peen, finish flush.

Or, grease the tang of the knife with lithium grease, put the halves on, wire together, then solder. The grease will keep the solder from sticking to the tang.

golfer1 · Mar 25, 2017

Where to you guys get you hard silver solder?

t1mpani · Mar 25, 2017

golfer1 said:
Where to you guys get you hard silver solder?

Jantz Supply has some called Safety-Silver 56

Dunno about its suitability in this case--may be perfect, but the melting point of NS differs depending on how much zinc is in it---it'd be rather embarrassing to get it all cut out, pinned etc and then melt it.

Bill DeShivs · Mar 25, 2017

You won't melt nickel silver while hard soldering it. If you do, you don't know what you are doing.
Jantz's solder is 56% silver. It melts around 1300 degrees.

t1mpani · Mar 25, 2017

Bill DeShivs said:
You won't melt nickel silver while hard soldering it. If you do, you don't know what you are doing.
Jantz's solder is 56% silver. It melts around 1300 degrees.

Well, I DON'T know what I'm doing, but this armed with new info I will look into the hard stuff. Thanks again!

tkroenlein · Mar 25, 2017

I don't know diddly about knife making, but a tad bit more about soldering.

If I'm correct about your plan, you intend to solder these two halves together, and slip it over the tang and and attach with a corby. Correct?

So what you want to do is called "tinning." This is where you coat each mating surface in a thin layer of solder. Then you clamp the pieces together, and heat until it flows. Remove heat and then wait for it to cool. This will not produce a "blob" of solder flowed between a joint, but an alloyed joint many times higher in tensile strength than the base material. You need a fit of .001" for this to occur. It is a very strong joint, used for putting double barrel shotguns together, for example.

Here is a link to brownell's high force 44. It will do what you want at 475 deg (propane torch from the hardware store.) You can buy the flux core for this and be just fine.

Hope that helps.

Oops. Here's the link.
http://www.brownells.com/gunsmith-t.../solders-flux/hi-force-44-solder-prod709.aspx

Sent from my iPhone using Tapatalk

Bill DeShivs · Mar 25, 2017

I don't suggest trying hard solder for your pommel. I said that's what I would do, but I have quite a bit of experience. Hard soldering does require a torch.

The Brownells' solder is as good as any low temperature solder.
Tinning can make for a good joint.

t1mpani · Mar 25, 2017

tkroenlein said:
I don't know diddly about knife making, but a tad bit more about soldering.

If I'm correct about your plan, you intend to solder these two halves together, and slip it over the tang and and attach with a corby. Correct?

So what you want to do is called "tinning." This is where you coat each mating surface in a thin layer of solder. Then you clamp the pieces together, and heat until it flows. Remove heat and then wait for it to cool. This will not produce a "blob" of solder flowed between a joint, but an alloyed joint many times higher in tensile strength than the base material. You need a fit of .001" for this to occur. It is a very strong joint, used for putting double barrel shotguns together, for example.

Here is a link to brownell's high force 44. It will do what you want at 475 deg (propane torch from the hardware store.) You can buy the flux core for this and be just fine.

Hope that helps.

Oops. Here's the link.
http://www.brownells.com/gunsmith-t.../solders-flux/hi-force-44-solder-prod709.aspx

Sent from my iPhone using Tapatalk

That's exactly my plan--and thanks for the heads up, I will check that link out!

Truth be told, I didn't not know that much about knifemaking myself, beyond grinding, steel properties, and how to surface prep for adhesive; I just love it.

Bill DeShivs said:
I don't suggest trying hard solder for your pommel. I said that's what I would do, but I have quite a bit of experience. Hard soldering does require a torch.

The Brownells' solder is as good as any low temperature solder.
Tinning can make for a good joint.

I think we responded at pretty much the same time, so I didn't initially see this. Yes, I'm thinking the lower temperature stuff sounds more my speed at this time. As always, I appreciate the vast and generous knowledge this forum provides.