Soldering 416 and D2

Jeff Conti

Well-Known Member
I have searched for tutorials on soldering and seem to be stuck (not finding what I am looking for). I've seen a youtube vid on soldering brass and when applied (I may have done a poor job) the tactics I seem to have failed badly. I'll post a similar question on the WIP and tutorial section. I'm guessing that this isn't a new question and perhaps I'm using the wrong materials (Stay Clean flux and solder).
My process:
wash the knife and guard with soap and water
spray break cleaner on both
settle knife in the guard (balanced on 3 nails driven into wood)
apply lighter fluid liberally
apply flame
apply Stay Clean to the joint
Heat to brown
apply solder
FAIL
I'm guessing there is a problem with "cleaning" or the solder/flux are old (10 years).
 

Sticks

Well-Known Member
What I do, and have not perfected this but get OK results, is clean the surfaces with acetone,then rubbing alchohol. Any remnant of rouge, wax or oil will be a problem. Use stay brite flux and solder(as you noted). I've used the hardware store leadfree solder and its OK, but Stay Brite is better.

Apply some pieces of solder over the guard blade "joint". Apply the flux. Heat from the bottom, i.e. beneath the guard, very slowly. (You may even pre-heat before applying the flux.) Once the flux "burns", which happens in a hurry when overheated, its won't work. I think "brown" is burnt. Loveless says in his book when the flux begins to boil the solder should run. I've never seen that. But, the idea is to be very concerned about the flux overheating.

I don't think you can apply the solder as it unrolls as you may when soldering plumbing. That's why I cut a few small pieces and lay them end to end over the joint I want to solder. And don't forget to use a No.2 lead pencil to put graphite wherever you don't want the solder to be when your done.

Jay
 

Jeff Conti

Well-Known Member
Thanks Jay.
I think I was overheating the flux. How do you apply the flux (after the solder pieces are laid down?). I used to paint the flux on the areas that I wanted to but that never seemed to work either (maybe I burned it then too).
 

smithy

Well-Known Member
The first rule of soldering is that cleanliness is absolutely necessary. Use soap & water first, followed by alcohol. The second rule of soldering is that the parts must fit together perfectly. Solder will not fill a gap. The third rule is that both pieces to be soldered must reach soldering temperature at the same time for the solder to flow. Solder will always follow the heat, so first heat the pieces together by directing your flame all around both pieces to get them hot together. When the solder melts, quickly direct the heat to where you want the solder to go. If you have applied the solder in snippets around the joint, bring your flame to the opposite side to draw the solder through the joint.

Some notes on "soft" soldering,ie lead based solder that melts at about 400 degrees F as opposed to "hard" soldering which is based on a silver or gold based solder which melts from 1050 degrees:

1. Do not use too much solder. If you are using soft solder, flatten the round solder wire flat and then "snip" off what you need. I use snippets of solder aprox. 2mm x 2mm when soft soldering. I use about 3 snippets per side.

2. If your flux turns brown or black, stop and clean it off and start over. The flux is shot and you will not get a good joint

3. When soldering, keep your torch moving about the joint continually or you will get hot spots where the solder will melt in a glob and not flow throughout the joint.

4. Be careful of the flux that comes with most soft solder. If you apply too much and it runs over your blade, a stain on the steel may happen. I use a Q-tip to remove any excess flux
from the joint.

5. DON'T TRY TO RUSH--it only causes problems.

I am really new to knifemaking and I have a question (not trying to hi-jack this thread). If anyone out there "hard" solders the blade and guard, do you do it before or after H/T? ...Teddy
 
Last edited:

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
I've done enough soldering to know I will never do it again. I use JB Weld instead of soldering now with out exception. Soldering is not impossible. Like everything, it just takes practice. I don't like the clean up as it always takes too long - for me. Your mileage may vary.

I do know flux heated to brown won't work. Get it to where the flux bubbles and melts and then keep sneaking up to solder melting point.
 

Sticks

Well-Known Member
Thanks Jay.
I think I was overheating the flux. How do you apply the flux (after the solder pieces are laid down?). I used to paint the flux on the areas that I wanted to but that never seemed to work either (maybe I burned it then too).
Jeff,

I use a small paintbrush to apply the flux. Just remember the flux is very corrosive! Any that spilled or leaked on to anything iron or steel (vise, files, etc.)will change it to rust overnight. And remember to "wash" the soldered guard and blade well to remove any flux left after you solder. I rinse thoroughly and soak/agitate in baking soda and water. Some, I've read, boil the soldered blade/guard in baking soda water. I thought that this was one of those "Ya sure!" concerns, but the other day I noticed that a knife I finished several years ago was showing a black line where the guard meets the spine. It buffed out, but I think it was caused by flux I hadn't removed.

Jay
 

kamikazej

Gold Membership
I've done enough soldering to know I will never do it again. I use JB Weld instead of soldering now with out exception. Soldering is not impossible. Like everything, it just takes practice. I don't like the clean up as it always takes too long - for me. Your mileage may vary.

I do know flux heated to brown won't work. Get it to where the flux bubbles and melts and then keep sneaking up to solder melting point.
Boss dose the JB Weld work without pins ? I'm thinking of adding Mosaic bolster's to a damascus knife and wouldn't want pin's in the mosaic.
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
I will not work with out pins. It just seals the crack so no moisture can get in there...
 
Top