[AT] A long shot--Wisconsin part

[John Wilkens]

Thanks for the information Mike.  Hope you won't mind one more 
question.....   I've only just used the flux-covered brazing 
rod.  What method would you use to use "plenty of good flux?"  How 
and when do you apply it?  Is it the usual powered flux that you 
would dip your hot brass rod in?    John




At 11:52 PM 06/28/2006, you wrote:

>  John:  I might be able to offer some information on the rubbing of 
> the carbon stick on the weld.
>
>If you've ever had a nice fresh cast iron weld crack on you, you 
>will have noticed that it doesn't crack on the weld itself, it 
>cracks on either side of the weld.  without getting into all the 
>science as to why that happens,[I've tried for years to understand 
>it] it is basically because the heat of the weld draws the carbon 
>from the surrounding part of the metal to the heat zone of the weld, 
>and causes it to crack. So the theory was that the carbon would help 
>to fill in at the spots it was being pulled from, this is also the 
>reason for the pre and post heating, and burying in sand or lime, etc.
>
>  I do all kinds of welding on an almost daily basis, and a part of 
> that is sometimes cast iron, some of it with stick, and some of it 
> with heli-arc, I dislike it very much, there have been really great 
> products developed in the last 20 or so years for cast iron 
> welding, but its whole purpose is for
>repair, I have never seen it as a means of normal cast iron joinery. 
>No mater how much I've done, or what I see others far more talented 
>and informed than myself do, I just can't seem to get comfortable 
>with the whole idea of cast iron welding.
>
>That being said, my preferred method for the repair of cast iron is 
>brazing, be it with brass, silver, or with cast iron filler, it just 
>seems to "work" better. Just remember, clean, clean, clean, and 
>plenty of quality flux, and of course never forget that brazing is 
>dependent on capillary action, it is not a soft weld.
>
>  This is just my opinion, I hope it is of some help   ........ Mike
>
>





                    In the wide-open spaces of NE Oregon