Forge welding 15N20 into a usable thickness by hand?

A

AlaskanHunter

Joined
Nov 23, 2013
Messages
306
I've got some of JT's 15N20 that I've been using, and I'm loving it. I would like to attempt to use some of it for hunting/general purpose knives but I think it's a bit too thin as is. I've heard a bit of chatter about forge welding a few layers together for a more usable thickness. I've had hit and miss luck with forge welds and borax up until now. There always seems to be a small part that just won't stick, ruining the part (or all) billet. I am using a waste oil forge, so it's not quite as controllable as a propane forge, but it is pretty good. Would MIGing around almost the whole billet, leaving maybe an 1/8" - 1/4" gap and doing a kerosene forge weld work? Obviously I'd have to grind off the MIG bead after the forge weld was done. Does grinding the surface of the pieces before forge welding help?
What do you all think, good idea or bad? Is there a better way that I'm overlooking?
JTknives JTknives , I'd greatly appreciate it if you had the time to weigh in with your expertise on the subject!
 
If the layers are sealed from the air then no flux is needed. By welding all the way around you are protecting the layers from oxidising.
 
Yes grind the pieces as clean as possible before starting. if you Mig around all the seams that is a dry weld and the advantage of this is the oxygen left between the individual pieces is burned off when you get the billet hot and no oxygen can get back in there. the advantage of using flux is you know when the billet is hot enough by when the flux starts to dance. if you keep the oxygen from getting in your pieces and get it all hot enough, no shadows showing at all in the billet, your forge should be fine. just remember to keep the oxygen out and get the temp hot enough.
 
A trick for knowing when the billet is hot enough is to take a piece of 12 gauge mild steel wire ( a coat hanger is good) and when the billet looks hot enough, stick the wire in the forge for a second, pull it out and dip in a cup of flux, and then stick back in and push against the billet. If the billet is at welding heat, the wire will stick to it almost instantly. If it doesn't, heat a bit more. Re-test with the wire until it welds to the billet. To get it off just give it a twist.
 
Stacy E. Apelt - Bladesmith said:
A trick for knowing when the billet is hot enough is to take a piece of 12 gauge mild steel wire ( a coat hanger is good) and when the billet looks hot enough, stick the wire in the forge for a second, pull it out and dip in a cup of flux, and then stick back in and push against the billet. If the billet is at welding heat, the wire will stick to it almost instantly. If it doesn't, heat a bit more. Re-test with the wire until it welds to the billet. To get it off just give it a twist.
Click to expand...

last time i did that it stuck so good i could not get the wire off and had to pull the billet out and yank it off with pliers lol
 
" ... To get it off just give it a twist. ..."
"last time i did that it stuck so good i could not get the wire off and had to pull the billet out and yank it off with pliers lol"

Yes, and I bet you twisted it off with the pliers :)
 
Stacy E. Apelt - Bladesmith said:
" ... To get it off just give it a twist. ..."
"last time i did that it stuck so good i could not get the wire off and had to pull the billet out and yank it off with pliers lol"

Yes, and I bet you twisted it off with the pliers :)
Click to expand...
I guess that means that you had the temp just right? Thanks for the advice! Now I just need some time at my forge.
 
That was back when I did not weld my billets I wrapped them with coat hanger wire. I think if I remember correctly I axadently touched the coat hanger tip to the coat hanger wrap.
 
It seems that most folks that are doing the "kerosene" weld are using either kerosene or WD40. Kerosene is not available locally, but I'm wondering if #1 heating oil or JetA are suitable substitutes? After a little research, it seems that they are close enough, but the dye in JetA may be a problem.
 
Hardware stores will often have kerosene in gallon jugs for use in heaters.
Mineral spirits and paint thinner are quite similar to kerosene, and would probably work. I often use kerosene for jobs those two would usually be used for
 
Geoff Flato said:
Hardware stores will often have kerosene in gallon jugs for use in heaters.
Mineral spirits and paint thinner are quite similar to kerosene, and would probably work. I often use kerosene for jobs those two would usually be used for
Click to expand...
Hardware stores are nice - if you have them. I live in a small Alaskan village, and all our fuel is flown in with a C-46. If you need something other than their usual loads (100LL, JetA, 87Unleaded, or #1 Heating oil) then it's going to come HAZMAT airfreight....$$$. I'm hoping I don't need to go that route, but if I have to, I will.
 
#1 should work fine, if it's not dyed. We burn #2 here and it is dyed. I don't *know* dye will make it unsuitable. That's a possibility. Given your constraints I would try #1 and a couple bits and see, dyed or not.
 
I'd reckon any of those would work if undyed
Some guys use non chlorinated brake cleaner, and that's way more flammable than gasoline
 
DanH45 said:
#1 heating oil should work, and as far as I know diesel should work fine.
Click to expand...

In a pinch, you can use kerosene in a Diesel engine and it'll run. I've got 15 gallons of diesel that was contaminated with gasoline, so it was drained from the fuel tank on a truck. I'll be trying it out next week to see how it works.
 
You must log in or register to reply here.
Back
Top