Advice about heattreating and welding

[JohnC]

Hello, I'm partway through making another knife, after seeing the bushtool elswhere and admiring the shape, I fancied trying putting a plate on the butt of a handle.

I plan to weld it on, but does anyone know if the right thing is to heat treat first, then weld or weld it on then heat treat? Or doesn't it matter?

01 steel 3mm

 

[spamel]

I'd weld it first, I reckon that would make more sense, but have you considered soldering it if you want to do it the other way round?

 

[JohnC]

Thanks for that, it makes sense, I'd rather not solder it, as I wanted to use it fro light(ish) hammering/crushing.

 

[Ogri the trog]

I'm guessing that it wouldn't really matter,
the plate being sufficiently far enough away from the important bits not to effect the heat treatment adversely.
But then I'm not a welder so feel free to ignore anything I say......

Ogri the trog

 

[Bernie Garland]

Weld it first,but i would have drilled a hole in the butt cap and tenoned the butt of the knife into the hole and filled the hole and tenon with weld,that way you have a nice square butt plate and easier to fit the scales,instead of trying to shape the scales round the weld,hope you get what i mean.

Bernie

 

[FGYT]

weld first as heat treated dosnt like being welded and can be very weak

ATB

Duncan

 

[Dave Budd]

it doesn't matter whether you weld first or heat treat first, since it's so far away fromt eh blade the welding won't affect the temper of the cutting edge

Only advice would be ot normalize the weld so that it's not brittle. Welds never break, the metal on either side of it does though. Known as the Haz zone, basically the grain grows and there is a sharp contrast between the superheated area next the the weld and the normal steel further away from it. All you need to do is heat the area to non-magnetic and leave it to cool, repeat if you like. Many welders will go over criticle joints two or three times to fade the hz zone into the good steel

If I were doing it I would weld first, normalize the back end a few times and then heat treat the blade. But you could do it by heating the back end with a torch and only normalizing the end. Mind you, even if normalized if you are no good at welding then it won't stick!

 

[spamel]

Weld it first,but i would have drilled a hole in the butt cap and tenoned the butt of the knife into the hole and filled the hole and tenon with weld,that way you have a nice square butt plate and easier to fit the scales,instead of trying to shape the scales round the weld,hope you get what i mean.

Bernie

I get you Bernie, that is the method I would use if soldering it!

 

[JohnC]

Many thanks for the advice, my welding is never pretty, and the pieces are 3mm thick so there'll be some practicing first I think.

 

[Singeblister]

If I was to weld it on I would heat treat first and wrap a wet rag round the blade. However I would solder it on after heat treat using the same method

 

[Scrumpy]

If you hold as much of the metal as you can in a metal vice this will slow up any heat transfer a lot.
Secondly why not silver solder it, very strong and quite easy to do, or braze it on?

 

[demographic]

Welds never break, the metal on either side of it does though.

Apart from when they are full of porosity or have lack of sidewall fusion, lack of root fusion,lack of interpass fusion, hydrogen embrittlement*, slag inclusions, solidification cracks, and a few others I can't remember the details of tonight , no the welds don't crack.

*Hydrogen embrittlement is usually in the parent metal (as you pointed out HAZ cracking) but can sometimes occur in the weld. Usually at the weld toe.



















Sorry to be pedantic but I used to work as a weld inspector and industrial radiographer years ago before the bottom fell out of engineering up here and I retrained as a carpenter

 

[big_swede]

If you hold as much of the metal as you can in a metal vice this will slow up any heat transfer a lot.
Secondly why not silver solder it, very strong and quite easy to do, or braze it on?

Agree, braze with silver or brass.. I would make a tendon with the brazing to..

 

[Dave Budd]

Apart from when they are full of porosity or have lack of sidewall fusion, lack of root fusion,lack of interpass fusion, hydrogen embrittlement*, slag inclusions, solidification cracks, and a few others I can't remember the details of tonight , no the welds don't crack.

*Hydrogen embrittlement is usually in the parent metal (as you pointed out HAZ cracking) but can sometimes occur in the weld. Usually at the weld toe.

Sorry to be pedantic but I used to work as a weld inspector and industrial radiographer years ago before the bottom fell out of engineering up here and I retrained as a carpenter

My bad :sulkoff: GOOD welds don't break! (All second hand knowledge gained sometime ago for me I'm afraid )

 

[Mike Ameling]

Another possible option --

Weld two flat tabs up from that but cap - just wide enough to slip the handle between the tabs. Then drill and rivet in place. The handle slabs would cover up those extra tabs and the rivet.

But since this is the far end of the handle, there is less concern about heat-treat of the blade. The handle already needs to be left soft/annealed for strength/toughness and workability. Clamping the cutting portion of the blade in a vise to protect its heat-treat from the welding heat works well. And playing a little heat from a torch over that end cap and handle after welding does help "normalize" the area. You can also clamp two thick iron bars on the sides of the knife blade to act as a heat-sink instead of clamping it in a vise. This would make it a little easier to move it around when welding that butt cap on.

Just another thought to share. Take it as such.

Mikey - yee ol' grumpy blacksmith out in the Hinterlands

 

[mick spain]

I wouldn't touch o1 with welder it's not recomended, but if you do it requires pre heat, weld, then post heat, depends what you are going to weld it with as well then HT the complete thing
As someone has already said they was a welding Inspector, that was my job at one time I was a coded welder as well, not at the same time though

I do it by grinding a spigot on the end of the tang. hole in the butt cap with a bit of a counter sink, pass the spigot through the hole heat the spigot up and rivet it on, then HT the whole thing. I have done many like that, and never had a problem

I have seen many welded items crack months after welding on this type of material and mostly when it's very cold, so wouldn't chance it

Here's a pic of how I finish it off

 

[demographic]

As someone has already said they was a welding Inspector, that was my job at one time I was a coded welder as well, not at the same time though

I was a coded welder before a weld inspector as well, its one of those natural progression things.

All my welding qualifications and even my NDT quals have long since run out now though as for some reason they don't think its a good idea to let someone who hasn't been doing it for years start using radioactive isotopes to check pipes.

Dunno why though

 

[mick spain]

I was a coded welder before a weld inspector as well, its one of those natural progression things.

All my welding qualifications and even my NDT quals have long since run out now though as for some reason they don't think its a good idea to let someone who hasn't been doing it for years start using radioactive isotopes to check pipes.

Dunno why though

Yep seems to be the progression, although I have come across quite a few inspectors who have never struck an arc
all my quals are run out now, but I changed back to welding a couple of times and then inspection, but to be honest I hate the site of welding now

Nice to talk to someone who has done the same work, it took me all over the world though so can't grumble at that,

 

[michiel]

I don't care how you do it, it looks great!

Mick, too bad you stopped making knives fulltime. How's your health coming along?

 

[mick spain]

I don't care how you do it, it looks great!

Mick, too bad you stopped making knives fulltime. How's your health coming along?

Hello Michiel, Thanks
I'm alright apart from my shoulder I have to see the surgeon tomorrow, to see how he is going to do the op, then I will know when I can Retire