Hope this is the right area to ask this. Anyway, I've tried to solder a finger-guard on a blade twice, with only one (moderate) success. Do you guys use this technique, and if so, any advice? Do these "heat-resisting" pastes work to contain heat away from where you don't want it? Thanks for any help.
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Soldering
- Thread starter mlminto
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- Nov 27, 2002
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Shop talk...
What materials are you trying to solder..?...What solder and flux..?
Please describe your technique..
What materials are you trying to solder..?...What solder and flux..?
Please describe your technique..
Bill DeShivs
Knifemaker / Craftsman / Service Provider
- Joined
- Jun 6, 2000
- Messages
- 12,882
And, no- the heat resisting pastes won't work very well in your application.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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You don't need to contain the heat....you need much less of it to start with.
The normal solders used to solder guards on melts at around 450F. Some melt as low as 275F. Use the smallest flame...or better - a heat gun. The main thing is to make everything CLEAN. Not just washed off clean, but REALLY CLEAN.
Some tips:
Everything needs to be tightly held in place. Some sort of clamp or soldering fixture is needed. I use a coil spring with excellent results. It is very difficult to get a good solder joint when the parts are just laying together. The only place where this works is a large blade ( bowie/camp) clamped in a vise with the tang straight up...and a large heavy guard. Even then, the tiniest bump or vibration may crystalize the solder joint.
Use low temperatures, small and "soft" flames or other gentle heat source. Over heat the joint and the solder will stop flowing....and no amount of flux will make it flow. If the flux gets dark or gummy looking, just stop and go back to square one.
Go slow, it takes time for the metal to slowly heat up to 400F. Heat the largest mass with the highest coefficient of heat most. That will normally be the guard metal. Just play the heat across the blade and tang from both side every now and then. Heat too fast and you will almost surely burn the flux....and the solder will NOT FLOW....no matter what you do.
Flux well with the proper flux.
Place/add solder in/on the joint from the opposite side as the heat source, especially if using a flame. Solder flows toward the heat. If you heat from the same side as the solder, it will only ball up. If you put the flame directly on the solder it will oxidize and won't flow. If it beads up when the flame is run across it....quit, clean and sand all surfaces, and start over again.
When the solder starts to flow, REMOVE the heat source immediately. Re-flux, and add more heat gently as needed as you feed in more solder.
You should only need a small amount of solder.
LET IT COOL....don't touch or move the knife for five minutes. That is overkill, but if the joint is moved or any vibration/shock affects the joint until it is completely cooled the joint will crystalize and be bad. It may look ok, or just a bit frosty, but will pop apart with almost no effort.
All that makes soldering sound hard, but when done properly it is a 1-2-3 process that takes less than a minute once all is ready.
The normal solders used to solder guards on melts at around 450F. Some melt as low as 275F. Use the smallest flame...or better - a heat gun. The main thing is to make everything CLEAN. Not just washed off clean, but REALLY CLEAN.
Some tips:
Everything needs to be tightly held in place. Some sort of clamp or soldering fixture is needed. I use a coil spring with excellent results. It is very difficult to get a good solder joint when the parts are just laying together. The only place where this works is a large blade ( bowie/camp) clamped in a vise with the tang straight up...and a large heavy guard. Even then, the tiniest bump or vibration may crystalize the solder joint.
Use low temperatures, small and "soft" flames or other gentle heat source. Over heat the joint and the solder will stop flowing....and no amount of flux will make it flow. If the flux gets dark or gummy looking, just stop and go back to square one.
Go slow, it takes time for the metal to slowly heat up to 400F. Heat the largest mass with the highest coefficient of heat most. That will normally be the guard metal. Just play the heat across the blade and tang from both side every now and then. Heat too fast and you will almost surely burn the flux....and the solder will NOT FLOW....no matter what you do.
Flux well with the proper flux.
Place/add solder in/on the joint from the opposite side as the heat source, especially if using a flame. Solder flows toward the heat. If you heat from the same side as the solder, it will only ball up. If you put the flame directly on the solder it will oxidize and won't flow. If it beads up when the flame is run across it....quit, clean and sand all surfaces, and start over again.
When the solder starts to flow, REMOVE the heat source immediately. Re-flux, and add more heat gently as needed as you feed in more solder.
You should only need a small amount of solder.
LET IT COOL....don't touch or move the knife for five minutes. That is overkill, but if the joint is moved or any vibration/shock affects the joint until it is completely cooled the joint will crystalize and be bad. It may look ok, or just a bit frosty, but will pop apart with almost no effort.
All that makes soldering sound hard, but when done properly it is a 1-2-3 process that takes less than a minute once all is ready.
ah, yes - I guess it would help to tell just what i'm trying to do. Attempting to solder 360 brass to O1 and 1095 steel; well cleaned, fluxed, held in a vise and heated with a propane torch from the handle area up towards the brass finger guard. thanks again.
Bill DeShivs
Knifemaker / Craftsman / Service Provider
- Joined
- Jun 6, 2000
- Messages
- 12,882
Not just clean metal, FRESH metal that has not had time to oxidize. If the blade is secured in the vise too close to the joint, the vise will act as a heat sink and interfere.
I use Stayclean brand liquid flux. For brass and carbon steel, you can even use lead solder. Stainless requires the solder have a tiny bit of silver in it.
I use Stayclean brand liquid flux. For brass and carbon steel, you can even use lead solder. Stainless requires the solder have a tiny bit of silver in it.
