Newsgroups: rec.crafts.metalworking,rec.woodworking
Subject: Re: BS blade welding
From: jmorton@euler.Berkeley.EDU (John Morton)
Date: 22 Aug 1994 20:04:24 GMT

In article <3333m9$is1@maggie.austin.wireline.slb.com>,
George Uptain <uptain@wildcataustin.wireline.nam.slb.com> wrote:
>
>Can anyone direct me to info on how to use the bandsaw blade welding 
>machine that is attached to our DuAll metal-cutting bandsaw.
>There seems to be four parts or stages to this. 
>1) cutting 
>2) grinding 
>3) annealing 
>4) welding

This may seem like a simple case of RTFM, but actually those DoAll
blade welders can give you a lot of trouble if you hit the wrong
thing at the wrong time.

1) Cut the blade to length.

2) Grind the ends so that they touch across their width when
butted together.

3) Raise the upper lever to vertical, then push it back to horizontal;
if the machine was left at the end of a previous weld cycle, this step
should cause the jaws to be seperated by about 3/8".

4) Clamp the blade ends into the welding fixture; they should butt
together in the same plane, and the joint should be centered.

5) Push the "weld" button, holding it for about 1 second so it can
enter the weld cycle.  There should be a shower of sparks as the jaws 
move towards each other and create the weld.

6) Let it cool a few seconds, then release the clamps, raise the upper
lever to vertical and back to horizontal again.  This time the jaws
should be maybe 3/4" or 1" apart.  

7) Clamp the blade as before, then stab repeatedly at the "anneal"
button to bring the weld to bright orange heat, then slowly back
to cool off.  Don't hold it down or you'll burn it up.

8) Let the blade cool 30 sec. or so, then flex the weld a few times;
if it doesn't break now it will not break under normal service.

9) Grind the weld so that no lumps remain on the weld area.


The various settings should be tweaked experimentally until you
find out what works for the blade width and gauge you are using.
Basically it comes down to "too hot" or "not hot enough".

The tricky thing about these welders is that by not doing the whole
routine (as described above) you get marooned in the middle of a
cycle, and it won't do anything the way it's expected to.  I
can usually free it up by jogging the weld button to a point
where I recognize where it is in the cycle by the movement of
the jaws.

Good luck ...

John Morton					University of California
jmorton@euler.berkeley.edu			Mechanical Engineering
{decvax,cbosgd}!ucbvax!euler!jmorton		Machine Shop