My very first Forge Weld

O

Okie405

Joined
Sep 29, 2017
Messages
104
Today is the day !!!

My very first forge weld ever, will be successfully completed using Aldos 1084 and 15n20 for a 3 layer style San Mai. A set of kitchen knives for my wife.

I've done my homework, I think. Built a new forge with a real forge burner in it awhile back that gets plenty hot enough, got plenty belts for getting my mating surfaces shiny and fresh, got borax, learned how to weld last month.

I really want these two metals to stick/weld together nicely. Any advice for a first time forge welder. I've read the posts and am sure I know what needs to be done. I'm just nervous cause I tried it last year on my first forge that was one of them brick propane torch ones and it was an utter failure.

Wish me luck. I will share this evening how it goes.
 
Okie405 said:
I'm just nervous cause I tried it last year
Click to expand...
I remember that now! Good luck, but you know more than you did last year, so it'll go fine, I'm sure.

Not sure how much advice I can give, not knowing exactly what size everything is, but I'll share something I learned on my first san-mai attempt after a few years of doing damascus. My 15N20 is from broken saw mill blades at 0.070" thick and I doubled these up on each side of a 0.125" 1095. I tack welded the corners and in the middle of the 6" long billet. Because the outer material was so much thinner, they heated up and expanded a lot faster than the 1095 core and "bubbled" off the 1095. When I set the weld on the first heat, I swung a little harder than I normally would to flatten the 15N20 as well as set the weld, and ended up deforming the steel too much on the first heat to get a good weld, and the outer layer of 15N20 never fully welded.

So I guess my advice is, be more careful when setting your weld on your first heat when doing san-mai.
And perhaps don't tack the ends of the billet to allow the materials to stretch but remain flat.
 
If you want to make it a slam dunk, use your wire welder or TIG and weld the three pieces all the way around while clamped tight in the vise. Obviously, grind/sand all surfaces clean first. After forge welding them solid from end to end for sevearl heats, grind the edges clean of the weld metal, normalize, pickle, and make your knife.

If doing the weld as an open weld, weld the corners together and put a few other welds along the side. Weld on your handle if using one. Put in a can of kerosene to soak for an hour of so. Remove, let the excess kero drip off back into the bucket, and put in the forge. This is called hydrocarbon fluxing, and is only done once before the welding starts. Turn it regularly, and pull out when a coat hanger will self-weld to the billet when pushed against it. Warm the wire and dunk it in some borax flux, then push against the billet in the forge. If the billet is ready to weld, the wire will weld itself to the steel. Just give the wire a twist/pull to remove, wait five more minutes to make sure, and pull the billet to set the welds. Once you pull the billet, NEVER let it drop below a bright red color (1600F). Scale starts forming below that point, and you will not get a perfect weld.

Set the weld with medium blows quickly from end to end. Hammer a bit and put back in the forge before it cools below a medium red color. Dull red is too cold! Repeat several heats, then start increasing the force of the blows. You will hear the difference as the steel welds solid. No need for sprinkling with borax when using the hydrocarbon fluxing method. Repeat until it feels and sounds like a solid bar of steel when you are hammering. Let cool off and grind the edges clean to check the welds. If any still show a line, put back in the kerosene for a while, and repeat the welding until it is all solid.

Remember this rule:
It is hard to overweld a billet, but easy to under weld it. - Re-work the weld at least two more heats once you think it is all welded up.

Once the billet is welded, ground clean,and checked out, Do a normalization series of heats to reduce any grain growth. Then, soak in a bucket of pickle (PH Down) overnight to remove the scale. At this point it is ready to make a knife from the san-mai.
 
Last edited:
All kinds of things to say but I'm sure you've already read them in all the other posts.. however, when you think to yourself, ok, its ready to go.. close the door for at least another 5 minutes. I was told my first time, when you think its ready, wait 20 more minutes.
good luck.

edit: and what Stacy said.
 
Stacy gave really good instructions above. I've not tried the kerosene method, but use the "weld all around" method for SS San Mai and it works good. My only problem came up when a neighbor came over watching and while talking to him I let the billet overheat a bit..... almost melted really. My forge was too hot and when I took billet out and tapped with hammer and end of billet just crumbled.

Since I don't have a wire or tig welder I use stick welder to weld.
 
I should have closed the door and waited 5 minutes. It didn't weld. I think it wasn't hot enough. Was a bright yellow.

Going to buy a metal coat hanger now and some cut off disks. This is happening today. When I get back from the store I plan to regrind it all inside and out all shiny and new and weld it all back together again... or should I just start with new steel again?
 
Quick question. Cant find a metal coat hanger anywhere so I just got some of that weldable steel rod from the big box store. Same thickness as a coat hanger. Will that work?
 
Last edited:
Going again with new steel, got a full 4ft of each 1084 and 15n20. Take less time to prepare the new than to try and clean up the failed. Can always clean it up later
 
I9cTvcp.jpg
B8TxFbL.jpg
B8TxFbL.jpg
 
Just got the next attempt ground clean and scrubbed with acetone. Bout to weld it together.
50cadac5-5b14-4c47-bb4d-83b716fe1348

50cadac5-5b14-4c47-bb4d-83b716fe1348
 
Last edited:
Welded all the way around. I'm no pro at welding but they hold good. Fired the forge back up and will be starting round 2 here shortly.

 
Looking at photos in post #15 and I see where the bars are bent slightly leaving a small gap, especially at the end. I do not have the experience to know if that is a problem or not. On the few billets I've made I used a clamp to remove the gaps while welding.

Perhaps somebody can comment if the small gap could be an issue or not.

Ken H>
 
That's what color I tried to weld at last time. I'm going till the rod sticks this time..
20191005-143838.jpg
[/url][/IMG]

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