Breaking forge welds

[Steampunk Jim]

Hi everyon!

I've been struggling real hard with forge welding , with the intention of making San Mai. After some helpful advice tuning up my forge , I was able to pull off what I thought was a good forge weld . A day or two later I heated things back up to try and draw the billet out thinner so I could start grinding a knife, and almost immediately my welds popped wide open.

So my question: did I do something wrong to break my welds or did I not have good welds in the first place?

 

[DevinT]

Not good in the first place. Tell us a little more about what you’re doing.

Hoss

 

[Stacy E. Apelt - Bladesmith]

You don't just weld the billet once. Re-weld it several times.

The biggest problem is not getting the billet the same temperature all the way through. You need to let it soak at welding heat until it is fully heated and then set the weld gently. Once the weld is set, re-heat the billet and work it harder until it sounds and feels like a solid bar of steel. Then re-weld it again.

If using a small forge, it isn't harder to get the billet fully heated. Always run the forge for a good 15 minutes to get the forge lining fully heat soaked. There is a good reason people who do damascus regularly make a forge just for damascus.