Welding san mai on Jewelry rolling mill

[Natlek]

I don t know why this thread is locked ?

San mai on small rolling mill

What do you think about that ? Welding two steel together is more about right temperature not pressure ? I m talking about making one piece of san mai steel , just for one knife at time ? Say core steel 1.5mm and from side say 0.5 , 1 , 1.2 mm........ stainless . This is jewelry rolling mill...

www.bladeforums.com

OK , I found one small rusty cast iron Jewelry mill here and I borrowed it for a few hours .....
I prepared three samples for testing, all 6.5 mm thick ,10centimeters long and 3cm. wide . I was afraid for mill , so I grinded the welds on a surface grinder so that they were flush with the steel . All successfully welded. For the first sample , I adjusted the rollers on 6.5 mm. welded in one pass! The second sample at 6.4mm. welded in one pass. The third copy the same. I was afraid to try to stretch little samples because it wasn't mine roll mill . It was left over from his deceased father and he won't sell it to me. So I think that temperature welds, pressure stretches .........steel
I take lot of pictures but have no idea in which folder I put them and I have hundreds of folders .When I run on them I will post pictures here .Now I am looking on E bay to bye one and convert it to motor drive . Some of them are capable to handle almost 5 tons.

PS . * I clearly don't understand how a rolling mill works *

 

[JoeBusic]

It should work. It worked for me. Tried on a borrowed Vevor one, with hardened rollers. 1060 worked fine. 14C28N worked fine (I want it thicker than 4mm). Broke them and both had a clean break with no delamination. M398 to 14C28N didn't work. Probably messed up the temp. 14C28N was a 4mm and 2.5mm stock and it was rolled to 6mm. Just crank it and it will be still yellow on the way out.

 

[Brad Martin]

To forge weld you need the right heat and enough pressure to set the weld.
While rollers are normaly used in a forging process to elongate and thin a billet, they can be used to forge weld if the edges are fully welded and drawing out of the billet is as minimal as posiable.
Drawing out will change the pattern of the cladding steel and the more you draw it out the greater is the risk of ending up with the core off centre and or failed welds, some of the cheaper blanks do have centring issues.
It does seem best suited to large scale production once all the fine tuning has been done.
Heat loss through the rollers is not your friend, the faster the steel moves through the better for avoiding it.
There will be a sweet spot of heat, pressure and speed and it will vary as you change steel types and thicknesses.
I think a press with kiss blocks or a limit switch is a better option for laminating a blade, it cetainly is a better option for making a billet.

 

[Stacy E. Apelt - Bladesmith]

I tried it with a large 1.5 HP chain driven rolling mill. The rollers are around 4" diameter.
We were doing seven layers for damascus and it didn't work because the rollers sucked the heat out too fast. The other issue is the speed of a rolling mill. They are designed to move at a slow and manageable rate.
We didn't try san-mai, but figured it would have the same issues as the 7-layer billet. It started to weld but stropped fusing about halfway down the billet.
After the initial hammer welding of mokume billets, we used the mill to draw out , but you had to re-anneal often. That worked pretty good because the temperature is not an issue and the metal is much softer.

The best mill for doing damascus and sand-mai I have seen in videos is the McDonald mill.

McDonald Rolling Mill

Tharwa Valley Forge sells handmade knives and teaches a range of courses in bladesmithing, leatherwork, knifemaking, blacksmithing, damascus steel making, longbow making and more.

www.tharwavalleyforge.com