Silver brazing

B

blackboogers

Joined
Jan 16, 2002
Messages
219
Lets say you were going to silver braze a carbon steel tang to a damascus blade, what type of brazing wire would you use? Can you use pure silver wire or it alloyed with something else? Anyone that has done this do you have a product recomendation.
 
It's alloyed. I use Brownells silver solder unless I'm out, then I use silverloy because I can get at local plumbing supply houses.
 
BB
If it were me I'd use something heavyer duty than
silver solder. it would be a shame to a have a nice
knife speperating at the handle becauce of a weak point..
just my opinon..
 
I dont want to use solder, I want to braze it, with a acetylene torch. I want a silver brazing wire I believe it brazes around 100 degrees. Its the same type of brazing as with brass.
 
Try a welding supply for white brazing rod. It melts at a higher heat than bronze rod and much higher than the 'silver' solders used in gunsmithing or knifemaking. Very strong, used for carbide tipped tools and works well with 'Stay-Silv' flux. Borax also works but this flux is better.

Another option is real 'silver' solder from a jewelry supply, the hard and medium variety melt at cherry red temperatures and are very strong but require a well fitted joint as it flows like water and won't fill cracks/voids like the brazing rod. Same flux or borax also for this one.
 
100 degrees?
you must have a typo there
soft solder melts at about 400 deg. the others higher,

as R Dannemann said, that may work for you.
be careful you don't take the temper out
of the steel if your using it after
the heat treat and remember the heat you treat at
if your heat treating after the solder..
you don't want two pieces again.
  most makers I believe ele. or forge weld them together..
 
Dan makes a very good point. When I can I use a bridle joint and also solder. It does make a hump in the tang though unless you have enough thickness to mortise the primary end down enough for the bridle to be flush.
 
I was erading the book by Wayne Goddard and he silver brazes the tangs (on some of his knives) as well as the nut on the butt cap. He seems to feel that it makes if properly done a joint thats stronger than the tang itself. All I wanted to know if somebody has used a silver brazing product that worked well for them. That was a typo on the heat. I meant around 1100 degrees I would use a heat sink above the tang.
 
that's a 10/4
and yup if done right..
sorry I was just adding thoughts for the crowd.BB
my tail is tucked and my chin is on the ground..:(
 
I'm sorry if I appeared rude as I did'nt mean too. Sometimes on these threads a tangent developes and soon the original subject is gone. I like to use these forums to see if people have tried a particular product and if it worked well for them. I have a mig but from all that I have read the heat will destroy or possibly damage the surrounding metal. The silver braze (while somewhat hot)will quickly flow with much less heat than migging (also being a gentle heat rather than a shock heat of mig. I also want a hidden nut on the cap (being nickel silver) and I wouldent trust a soft solder to hold that. I found what I want in Mc master-carr and its very expensive.
 
OK I still love you...Just Kidding. 
 
 Have you considered drilling and tapping the cap?
or is it going to be to thin for the reach
of the treaded tang into the cap?  i.e.: number of
threads holding in side the Cap, being N/S
you'll have less thread holding strength of course
then a steel nut.
 
The silver brazing method is very strong. If you put a slot into the tang and then grind a point to fit the slot on the second piece, you will get a very strong brazed joint. I recentley tested this joint by using scrap material and silver brazed them together. I clamped the piece into a vice and then twisted the all-thread multiple times until the joint failed. When I examined the pieces I found that the joint did not fail but the all-thread had actually twisted in two. So in my humble opinion the silver brazed joint has more than enough strength. The brand I use is Stay-Silv 15 with Stay-silv flux. The package does not state the temperature it melts at but I would guess 1000 degrees or more. I purchase mine at a local welding supply.
 
Blackboogers, silver solder and silver brazing are the same thing. They have to be done with a hot torch (Mapp/oxy is the coolest thing you can use and it's not recommended) I do use Silverloy and Stay-Silv works just as well. There are a host of other brands out there that work fine. The joint was mentioned because the type of joint is more important than the brand of solder. A butt joint is a poor choice. The idea is to have as much surface area as possible for the solder to bond to.

The joints are mentioned because it's difficult to recommend a solder without suggesting a joint. You are quite correct that migging, tigging or arc welding a tang makes a very weak tang.

There was a very good thread on this subject several months ago. Take a look at it for a lot of information:http://www.bladeforums.com/forums/showthread.php?s=&threadid=183406&highlight=solder+tang
 
BB

Has your blade been heat treated yet? I ask because I have Mig welded several carbon steel tangs to stainless damascus blades. I then normalized the whole thing. After normalizing I did a multiple blade smith aneal and then proceeded as normal. I used a but joint and scarfed the ends. I also angled the joint like this /. when I first did this I used some scrap pieces. I clamped the stainless in a vice and bent the carbon back and forth several times with no signs of failure. This was unhardened material. If yours has been hardend Then I would use the Hard silver solder. I said hard silver solder because there are some silver solders that are low temp and are often refured to as soft solders.
 
I've already made the knife, I just wanted to be ready the next time I get some damascus. I wasted 3 inches for the tang (keeping it one piece). Yes there is a world of difference between soldering and brazing (typically soldering is below 450 degrees and brazing is 450 and up). I found a site that sells silver alloy brazing material with the flux already embedded onto the rod. Its around 40% silver with other alloys. I will shape the tangs with male "v" and a female "v" I believe this will give the best strength. If course I will test my brazing technic first. I will also use a heat sink above the weld to protect the heat treat in the blade. Thanks for all the responses.
 
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