Bad Welds

P

pinpoint

Joined
Jul 17, 2001
Messages
234
G'day
I have had good success with welding up stacks of metal stapping and band saw blades and I've got some really good "course" patterns. However I've tried to weld up the stack, forge it down and then fold and weld, or cut and reweld the stacks to get a fine pattern. But I can't get the two stacks to weld together. Each time I hammer the stacks on the side the weld comes apart between the two stacks. On the stack that I cut, I ground a clean surface with a grinder and then welded the two ends together with a arc welder. After forging the stack down to about half the thickness I turned it on the side to even it out, but it came apart.
Any suggestions will really help
Thanks
Pinpoint:confused:
 
Pinpoint, Ive experienced the same thing especially when folding instead of cutting and restacking. I think the pieces need to line up very well with each other before welding them or they tear at the welded area. Be careful to not trap flux in the weld. It may be more time comsuming but Ive had the best welds by grinding to smooth clean metal and cutting and restacking. The layer count goes up fast if you cut your stretched bar into 3 or 4 parts each time. Hope this may help.
 
If it can go wrong it has for me.

I agree with Bruce try to keep the billet parralel. Its hard to know withiout seeing what you are doing. So I put in some things that I found cause me trouble.

If you let your billet get too wide before you try to get your sides narrowed that often causes de lamination not only the main weld but layers aswell. If you had say 1/4 inch thick and 2 inch wide that would cause you a bit of trouble trying to get it back to 1 inch wide.

If you hade the same 2 inch wide billet cut it into 4 bits welded them
twice to ensure good welds then tryed to narrow that on the side there should be less delaminating. Howeveryou would need to do some work on the flats as well as the sides. Well that is the general theory. the thickness are just examples.

The other thing that has gone wrong for me is if your gas is running low sometimes the welding heat drops off a little after a session.

edited..... I hit the side normally when the hottest straight out of the forge if I am concerned with the fresh weld ...

Hang in there you will get it. I have been lucky with brick banding which is only fine I started a billet about 6 years ago at a mates place with about 20 or 30 layers, may have folded once then twisted lovely.

The brick company now uses plastic strapping. you get that.
 
Bruce
It's good to know that I'm not the only one with this problem. My two stacks did not line up perfectly although I gave them a really rough grind, they weren't flat. I thought that would just be hammered out. So I'll get my stacks flatter and have a really clean surface. You know it didn't occur to me to cut the bar more than once. I'll now cut the stacks into 3 or 4 pieces.

Reg
How did you know my gas was getting low. In addition to the above I'll fix that as well.
They still use metal strapping a bit for packing heavy loads. I love using stapping and bandsaw blades that were just going to be thrown out.

Its good to make something really nice out of rubbish

Thanks for the help, it is invaluable.
Regards
Pinpoint
 
Would it help to weld all the edges of the bars together? I know it would eat up some time and welding rod but if it would decrease the chance of a bad billet it looks like it would be worth it.
 
I have had this problem in the past too. It seems to have come from not being hot enough when welding. After talking to Devin Thomas and Shane Taylor I have started to use more heat and letting my stack soak a little longer and then let it soak some more. I can now weld a stack grind fold weld then turn and forge on the side of the stack with no problems. I made this small billet this weekend by notching, folding, welding drawing out and then twisting. the bar was 4.5 inches long and 1.5 inches wide. I drew it to an inch square and four inches long before twisting.
 
Looks like you have a very sound billet there Bill.
I hope your going to show us the blade when etched.
 
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