Ignoramus15937 wrote:
On Fri, 30 Sep 2005 01:47:01 GMT, DeepDiver wrote:

"Ignoramus15937" wrote in message
...

You see the weld with slag removed, from both sides. I then used a
chop saw to cut the joined pieces to see what's happening in the
weld. To my surprise, the weld looked like it was original metal, no
sign of any dissimilarity or boundary.

It's very difficult to see dissimilarity and slight imperfections in metal
that has been rough cut. You should try grinding the cross-section smooth
and flat (a disc sander is ideal for this) and then polishing it. Then
you'll really see what's going on.


Here's what I tried.

I tried to do some destructive testing. I sliced a small slice across
the weld, put it in a vise and bent 90 degrees. Then I held it with
pliers and banged on it with a hammer, until it bent 180 degrees. It
bent and did not break.

The picture of the bent piece is in the same place.

http://igor.chudov.com/projects/Welding/02-Second-Weld/

If you want to subject it to an even tougher test, cut a longer length
(say 2") and hold it in the vice as before. Then bend it back and forth
instead of bending it just once. Eventually something will break. If
you're really unlucky it will be your vice :-), but probably it will be
the weld. If you did a really strong weld it will be the parent metal.
This type of test shows up slag inclusions because the repeated bending
gives cracks which begin at the inclusions the opportunity to grow.

As others have said, that's pretty good for a second weld. Well done.
Keep practising and soon you will have something resembling a rusting
modernist sculpture in your back yard!

Chris