Will soldering hold on bolsters?

E

ErikMB

Gold Member
Joined
Jul 27, 2017
Messages
870
Sorry for the stilly question, but I don't have a lot of different tools in my appartment and I would like to take my slipjoint making to the next level. I can get steel sheet metal and little blocks but I need some way to connect the bolsters to the plates. I have a soldering iron but not a full welding kit.

Does anyone know if this would be enough to fuse the bolster to the plate? Or is this just silly?
 
I think it would take forever if at all with a solder iron. At the least , I’d opt for a cheapo HF butane torch instead. Staybrite solder and flux, or Tix.
 
Tony Bose soldered all his bolsters an TA Davison still does. Both made/make top notch slipjoints.
I just soldered my first few bolsters. It takes practice and good flux but I enjoy it.
I use a small burner.
Look up Tony Bose soldering on YouTube. Those vids helped me a lot.
 
It's one of the accepted standard methods. The others are spot welding them or milling integral with the liner. I like to solder them, personally.
 
Soldering with Staybrite or TIX (my favorite) is the standard practice. Use the flux that is for the particular solder you chose. A cheap small $10 butane torch from Home Depot or anywhere is all you need. It takes very little heat, so don't overheat it and burn the flux. BTW, your soldering iron won't work.

Do a search on soldering using the Custom Search Engine and you will get lots of tutorials.
 
Would you be able to use your oven? The TIX Stacy mentioned melts at 140c-ish, so you just need a way to clamp them together
 
Stacy E. Apelt - Bladesmith said:
Soldering with Staybrite or TIX (my favorite) is the standard practice. Use the flux that is for the particular solder you chose. A cheap small $10 butane torch from Home Depot or anywhere is all you need. It takes very little heat, so don't overheat it and burn the flux. BTW, your soldering iron won't work.

Do a search on soldering using the Custom Search Engine and you will get lots of tutorials.
Click to expand...
Ah, thanks for pointing out the part of the soldering iron not working. I hadn't even thought to differentiate between heat source vs materials.

To me, soldering has always been for circuits. I hadn't thought outside of that box.
 
First, clean the blade and bolster with fine sandpaper. Everything should be flat and the joints meet properly.
Wash very well with dish soap and rinse with hot water. Dry off with a paper towel and don't touch any place you want to solder with your fingers.
Apply the flux to both parts and place together. Only use light clamping pressure if you have to use clamps at all. I use soldering tweezers.
Slowly heat the bolster and blade until it reaches the melting point of the solder. A small flame is all you need. A heat gun also works well.
Apply the solder to the joint as the metals heat up and when it flows back off the heat a bit and apply a bit more solder. Don't heat the solder, heat the metal. If the solder starts to melt but doesn't want to flow, apply a little more flux to the joint. Again, don't heat the solder, heat the metal you want it to join. The flux should bubble and maybe turn white (on some types) but if it burns, STOP, and start over by sanding and cleaning the metal parts again. Too much heat is a problem, too little heat is almost impossible with most small torches. A plumbers propane torch is about 100 times too powerful for soldering a bolster. Those little cheap refillable butane torches online and at the hardware stores are prefect. They are not good for much else but lighting a cigar but work perfect for soldering with low temp solders.
Use the heat source to draw the solder through the joint. The solder will flow toward the heat.
Use a solder pick to make the solder run down all the joints. It is a pointed rod with a wooden or other handle. I use solder picks made from 16 gauge steel wire, brass, and titanium ones. All work fine. They just break any oxides and surface tension along the joint and allow the solder to flow. Also, make a solder graver from a piece of 1/4" brass rod or square stock. Grind the end into a diamond shape point that can be used to cut away excess solder along the joint. The brass will cut the solder easily, but won't scratch the blade or bolster.

Once the solder flows, remove the heat. Don't touch or move the job for at least two minutes. If you do you can easily get a crystalized solder joint that will fail. Once cooled off, wash well and clean up. Do all filing and sanding necessary. If you have to use the belt grinder or polish the object on a buffer, do it gently and do not let it get hot or you can unsolder the joint from the friction heat.
 
Soldering is a bit of an art. Someone mentioned watching the Tony Bose videos and I'd second that recommendation. That's how I learned. Propane is perfectly fine for the job. That's what almost everybody I know who solders bolsters uses and I know a lot of really good makers who solder. Pro tip you won't get from Tony's videos, before you solder your bolsters to your liners take a q-tip soaked in flux and wipe flux on the edge of your liner where the bolster is going. It'll help the solder run up the edge of the liner and seal the seam when you mate the parts. Less issues with visible seams that way. ;)
 
Stacy E. Apelt - Bladesmith said:
Soldering with Staybrite or TIX (my favorite) is the standard practice. Use the flux that is for the particular solder you chose. A cheap small $10 butane torch from Home Depot or anywhere is all you need. It takes very little heat, so don't overheat it and burn the flux. BTW, your soldering iron won't work.

Do a search on soldering using the Custom Search Engine and you will get lots of tutorials.
Click to expand...

Always great advice!
 
Bill DeShivs said:
A propane torch is fine for someone who already knows how to solder.
It's a bit much for someone who doesn't.
Click to expand...
I'm right there in the middle.

Sounds like I should just do some practice before making an actual knife, huh...? ;-)
 
To clarify:
Propane is not the issue. Propane is what most every jeweler and knifemaker use for soldering. It is the size of torch. A propane plumbers Bernzomatic type torch has way too many BTUs for doing a soft solder joint. You only want to heat the joint to around 400°F max. A small jewelers propane/oxygen torch is the perfect tool but cost a bit more. The two main brands are Little Torch and Smith Torch. Amazon has lower priced Chinese clones that seem perfectly fine for soldering. These torches can be controlled to a micro-flame or a big flame that will melt silver. They are very good at hard soldering in gold/silver/brass/copper in the 1200°F range. They also do platinum well at 3000°F.

BTW, when jewelers and gunsmiths talk about soldering they are talking about hard soldering or silver brazing. Their "solders" melt in the 1000-1300°F range. When most knifemakers talk about soldering, they usually are talking about soft soldering in the 300-400°F range.

In the absence of a propane/oxygen torch. the cheap butane torches work best.
 
This thread has a lot of great information!

One question I'm not clear on - is soldering by itself a strong enough joint, or are pins also needed?
 
Figured I share a little more since I'm literally soldering bolsters on right now. Here is a handy and simple little alignment jig I made so my bolsters come out perfectly even everytime. Something I struggled with early on. It allows you to get everything lined up with the first liner then be able to clamp while still being aligned. Remove the bottom pins and slide the pivot/locating pin halfway out. Remove the liner from the jig and solder up! Pretty simple concept and it works perfect.
20230502_173130.jpg

20230502_173136.jpg

20230502_173204.jpg

20230502_173209.jpg
 
You must log in or register to reply here.
Back
Top