I have met the Devil, and his name is “Nickel”…
I know this isn’t much of an update, but I figured I’d take the opportunity to share with you some shop failures. It’s always at the times when you really think you’ve got things under control that something comes along and truly humbles you…
I have a new-found and deep respect for those who work with pure nickel in their pattern welding. I’m also now of the opinion that many of the people who say negative things about nickel in pattern-welded blade steel are only doing so because it’s such a pain to work with, not because of serious negative effects on the steel itself.
I started the current project in the exact same way as I’ve started every single pattern welding project to date. I researched the right materials and processes, called Delbert to discuss my findings and get any tips and tricks he had to offer, sourced materials (1018 and 201 nickel sheet in this case), and started carefully and deliberately to work.
To say that the first few results were a bit of a dissapointment is an understatement. Everything seemed to weld up properly, but under heavy forging or twisting, delaminations occurred on a scale I’ve never before seen in my work. I chatted more with Delbert, got more good advice, and soldiered on. More failures, but on a smaller scale. Instead of sections of the center of the billet delaminating when worked, it was down to some delamination of the top and bottom layers of the billet at the edges. Sadly, this requires an enormous amount of grinding to deal with. I have rescued a couple of billets though.
So, here’s the quick version of what I’ve learned about working with pure nickel…there will be MUCH more on this topic as time goes on, but this is the “30 second version”
- Augment your regular borax flux with about 25% of pure boric acid. The lower melting point helps coat nickel before it can oxidize.
- GRIND YOUR STEELÂ CLEAN. Even if you think it’s clean because it’s cold rolled, grind it.
- Weld HOT. I’ve been going at 2300+ degrees.
- Grind the sides of your billets flat after assembly. A good flat surface leaves less exposed nickel bits to oxidize and wreak havoc.
- Coat your billet edges with pure boric acid and melt it into a crust on the billet before the billet begins to soak. This may seem like a bit much (and I’m sure Del is laughing at me right now…), but it made the difference for me in the shop this morning.
- If you see a delam, or a crack. Grind it out ASAP. Unlike working with carbon steels, these little inclusions will not “work themselves out” during subsequent weld/draw cycles. Once nickel has oxidized, you’re done. Grind it off before moving on.
I’m pretty certain my issues were due to not getting flux applied and melted early enough. This would explain my top and bottom layer delaminations as those the outermost bars heat up first and will allow the nickel to oxidize. I’m now convinced that if the steel shows any color at all, even a dull red, it’s too hot and your nickel has oxidized. That’s why the boric acid helps, it melts at less than 400F and gets things coated BEFORE trouble starts. that said, it also burns off at a lower temperature, so your regular borax is still needed to handle the high end of the temperatures we work at.
I will be trying another technique used by jewelers to combat this problem as well and I’ll report on the results after trying it. Basically it amounts to dissolving boric acid in alcohol and painting it onto your workpiece. After that, the alcohol is ignited. The heat from the burnign alcohol melts the boric acid into a crust on the workpiece. This may end up being the way to go…I’ll let you know as I try it.
Just getting started with Damasus and Knives! injoyed the read! Thanks.
Keith Planche,Owner
http://www.kporiginals.com
kpswamp@aol.com
Bader