San Mai....in one hit?

[Tom Lewis]

Stacy, thanks for the suggestion. Where would you recommend I purchase the sodium bisulfate?

 

[Stacy E. Apelt - Bladesmith]

Home Depot, Lowes, any swimming pool supply, many hardware stores, hydroponics supply shops, water garden and pond centers, ebay, Amazon, etc. It is sold as ph down. Get the crystals, not the liquid acid. The crystals make an acid solution (sulfuric acid - H2SO4), but are safer to handle than the liquid.

A blast from the past :
In the past, sodium bisulfite was packaged and sold as toilet bowl cleaner. Vanish and Sani-flush were two popular brands. A few cents worth of a common chemical was sold for several dollars. It was banned because it ruined septic systems, among other reasons.

The same is true of the expensive roach control powders. Most are just borax/boric acid mixes.The raw chemical is sold by the 20# bag for the price of a can of roach powder.

 

[weo]

... are you saying that you had a ss/carbon billet cleaned up well, tacked only, and welded well with no flux and a fuel-rich forge? ...

My bad, my brain completely blanked out on the stainless adjective. Sorry about that all, please ignore my previous, ignorant, comment.

 

[Jesenius]

I don't have any mechanical forging equipment yet, and I just don't have the time or desire to do any laminating by hand.

But at work, I have a 400 ton brake press, and flat dies. . . .

I don't know if 400t hydraulic press is capable to make san-mai blade at one hit (probably Yes). A friend of My, Slovak blacksmith and knife maker Milos Gnida uses 30 tons hydraulic press (I think but I'm not sure). Here is a video clip from making a knife. I am pretty sure that He makes stainless steel san-mai blades too and they are very pretty. If You are interested You can see his work at this link. Here are SS san-mai knives. I think You can ask about his press at this link.

 

[kuraki]

Well I got my new forge welded up last weekend and I'm in the shop today to give this a go. Brought a lot of blade steel with me and have plenty of sst scrap to pick from. Just got the forge lined and a new flare on one of my burners and I'm about to start prepping and welding billets.

 

[kuraki]

So, I think it worked. My first trial I took a 1095 laser blank I had laying around, ground it clean, sandwiched the blade with 304 stainless which was also ground clean. I didn't screw around with acetone or kerosene or anything, just ground and sandwiched together in a vice. Then I TIGed up the perimeter with no filler. The 1095 was .25 thick so I ran 2 beads on each side.

I know this isn't ideal by welding through the ricasso, but this is just a test on cheap material. If it works out, it'll be a keeper knife.

Some challenges at the press but after working them out (my huuuuuuge dies are heatsinks. One hit and the billet is black). Heres an edge ground down. I don't have any acid with me to etch but you can see a faint transition line.

The tip had a delamination where I tried to start drawing it, but it was very shallow and I ground it out. Grinding it out I noticed the 1095 and 304 color differently when you get them warm, so I kept grinding to try and see what I have for adhesion. I think this is a good weld, but what do I know? Note, they're not changing color independently of each other, like an obvious weld failure. Just different shades at different rates. This was ground with a 40 grit flap wheel to take that for what it's worth.

So, I'm going to weld up some more billets and get them forge welded. I can draw them out later at home with a hammer if need be. This one is 304/80CRV2. I'll be doing 304/W2 as well. (Maybe I can get something with a hamon and a transition to stainless )

And since I had the laser running, why not make a sign for my shop

 

[kuraki]

I guess the answer is no, I can't. Every piece delaminated on one side as soon as I tried to draw out the edge. One side looks great, the other just pops off. I must not have heated them evenly.

 

[Tom Lewis]

Sorry it didn't work out. Thanks for all the pictures.
1. grind the surfaces and be sure they are clean before you stack them.
2. weld up all the edges.
3. immediately put in a forge that is up to heat. 2300 degrees.
4. let soak at 2300 plus degrees for 10-15 minutes.
5. press the billet together. I use a hydraulic press. I don't know why your press wouldn't work.
6. The stainless steel you are using may not draw out without delaminating. You may just have to use a stock removal method and not try to forge to shape. With 410 ss I have been able to draw the billet out.
Don't give up.

 

[kuraki]

Thanks Tom. I followed your steps but seeing you say 15 minutes at 2300 now I know I just wasn't hot enough consistent enough. I won't give up.

I had to rough grind this and etch it to Swede how it would look. It would have been cool. I'll finish it roughly and use it to break rocks or something.

I wore a camera through the welding process I'll see how that video turned out tomorrow.

 

[kuraki]

Oh, I just wanted to add - Cubitron 967F ceramic 50 grit is HUNGRY for 304 stainless. I've never used an abrasive that ate 304 that quick and cool. I started roughing this with a brand new 36 grit blaze. I didn't get one side beveled before it was toast. The 967 just tore through flattening the sides, finishing the bevel I started, and doing the entire other bevel. I was really impressed.

 

[kuraki]

Gave it another shot today following Tom's advice on heat. The only stock I had that was really suitable for a stock removal knife was some 2x.153 1084. Everything else was too narrow, too thick, etc. So I cut a 12" piece of 1084, then lasered out two 12x2 pieces of 304, cleaned everything up and TIG welded as yesterday. I noticed after reviewing yesterdays events in my head that I think Tom is really correct on the idea that drawing out a 304/carbon lamination is a bad idea, because every billet I made yesterday looked great until I started drawing. The W2 especially looked good, but when I began drawing it out, my TIG welds eventually burst rather than moving with the material, and the W2 began squishing out like a juicy cheesburger. I think that's where I lost the weld.

Anyway I also noticed I'd put a dip into my dies. So I milled them flat again to give myself the best possible chance for a good outcome.

Heating up. I soaked 5 minutes per side, and then for another 5-10 minutes I soaked by moving the billet in and out of the forge and flipping it periodically, trying to get as even of a heat as I could.

For what it's worth, I ran these burners at 10psi the entire time yesterday and today, from a single 20lb LP tank, with no freezing issues, etc.

Dies in the press. This press is controlled by limit switches. Since I only had one billet today, I set them to give it a .015" squeeze initially.

Then I went back into the forge, and brought it to heat again, making another .015" squeeze, and finally a third .015" squeeze. I then brought it to heat and beat the edge a bit with a ball peen to try and put some patterning into it. Nothing excessive. It didn't seem to delaminate, and my TIG welds never broke which I take as a good sign. Finally I brough it up to about 1500 evenly and let it air cool.

Hopefully I can do some grinding on this tonight and see what I've got.

 

[Tom Lewis]

Thanks for all the pictures. Thanks also for suggesting the Cubitron 967 belts.
I think if you don't try to forge to shape you should have a solid piece.

 

[kuraki]

Tom, you're the man. Thank you for your advice. That last billet came out perfectly. Now that I know not to draw, I'll start with thinner stock. This guy is going to be a bruiser.

Got this picked out for the handle.

 

[JG Custom Metal Works]

Man, I really like how that came out.

I wonder if this could be accomplished without a press? If I was able to weld up a billet entirely of high carbon steel and either 304 or 410 stainless and then set the weld by hand? Which would be a better stainless to use and, hell while I'm at it, what carbon steel would be optimal for something like this.

Sorry, not trying to hijack. It just looks so good I wanna try my hand at some stainless San mai. I've done non-stainless before but never stainless.

 

[kuraki]

JG- I think you could do it by hand I just think it would be hard to tell when your weld is set. If you have 410 I would use that which should allow you to do some drawing and forging to shape. I'm just using 304 because I'm swimming in it.

 

[JG Custom Metal Works]

JG- I think you could do it by hand I just think it would be hard to tell when your weld is set. If you have 410 I would use that which should allow you to do some drawing and forging to shape. I'm just using 304 because I'm swimming in it.

I'm not too worried about being able to draw it out and forging it to shape. My main concern is getting a good weld and not having to pay an arm and a leg for a premade billet. Any ideas on where to source 410 stainless steel for a decent price?

Which high carbon steel would be optimal for forge welding to 410? I have aome stainless steel San mai from Aldo that uses W2. Does it even matter which high carbon steel is used?

In terms of getting it to the proper heat, what colors should I be looking for? What are the signs of it getting too hot? I'll most likely use my Atlas Mini Forge. I was able to do non-stainless, San mai with 1084/15n20 but am unsure if it will have enough juice to do the stainless. It should though I think. I'm wondering if I should turn it on to max and let it rip? It has a max temp of 2350f, which I wonder if that would ruin my steel if inlet it sit for too long at that temp...

Again, sorry if I'm getting you side tracked here, I just can't get over how good that looks and the ease in which you seemed to be able to get it done.

Thanks again for making this thread! I appreciate the info.

 

[kuraki]

No side track, this discussion is the point of the thread.

You'll have to go at max as you want 2300-2400F. I don't think there is an ideal carbon to use. I welded A2, 80CRV2, W2, 1095 and 1084. They all welded fine. I just lost my welds when I tried to draw the billets out. The carbon moved easier than the 304 and broke the welds. I think you could use anything you'd like, with the caveat that the simpler alloys always seem to weld the easiest. I just ordered some .093" 52100 for more of this. .093 52100 core and the outside I'll use .060 304 for a 0.203" finished billet. 16 gauge is the thinnest 304 I have on hand unfortunately.

The hardest part about doing this by hand is knowing when your weld is set, which is why I think having a billet stack you know will hold up to drawing will help you, because you can go a little over board with your setting and not to the minimum required, without fear of losing your weld. Tom might have more insight on that. As I think about it, I think you're going to work one end to the other watching the arc welds you put along the edges. As you work, and they begin to stretch, you keep moving out so they don't break.

 

[Tom Lewis]

Kuraki, congratulations! beautiful blade.
There are those who know a lot more about this subject than myself. I don't consider myself an expert although I have successfully made stainless san-Mai.
JG, I like to use 410SS and O-1. 410SS can be purchased from Jantz. I don't hardly think you can get the billet too hot. After my forge reaches 2300 plus degrees I leave the billet in for 10-15 minutes. As far a colors, I like it to be the same color as the forge walls.
As far as setting the weld by hand, try it and see if it works. I use a hydraulic press with flat dies.