[Farmall] O-12 chores

[Robert Johnson]

Karl , have you tried using a DHC 2000 ?.
I got one a year or so ago.
It took some adapting welding techniques , but does work that i wouldn't 
even attempt any other way .
Rob J.
----- Original Message ----- 
From: <olmstead at ridgenet.net>
To: "Farmall/IHC mailing list" <farmall at lists.antique-tractor.com>
Sent: Wednesday, December 27, 2006 6:45 AM
Subject: Re: [Farmall] O-12 chores


>I agree that I have little to lose, John.  And welding cast iron is
> certainly a talent that I would like to have.
>
> What scares me is the guys who say "I've welded lots of cast iron, just
> zapped it with the MIG, and it worked fine".  That goes against everything
> I've ever read about what happens in the iron adjacent to the weld, which
> gets very hot and then chilled by the base metal.  It winds up being very
> brittle and under a lot of stress.  In order to do a lasting job on cast
> iron, the whole part needs to be virtually red hot while you are welding,
> and then cooled very slowly.
>
> Then there's the problem with porosity, contaminated metal, warpage,
> cracking and so on.  Doing it right is not a simple matter.  I figured
> that I might be able to learn to braze a lot quicker than to weld.
>
> Brazing and soldering are also magical techniques.  In order to do what
> the experts do, you need to control the temperature of the pool so closely
> that you can keep it in the 'mushy' stage, where it doesn't liquefy and
> run right off the work.  I've never been good at that.
>
> Gotta obtain some 2" round stock before I can start making crank
> supports....  none in my scrap pile.
>
> -Karl
>
> ----------------------------
>> Great read Karl. Definetly a good play by play for anyone resurrecting an
>> old machine for the first time and not certain what to watch out for.
>> Likewise a good reminder for the rest of us.
>>
>> Got a challenge for you. Learn to weld cast iron. It's something I can do
>> on
>> my own projects but don't really want to do for others. Then again a lot
>> of
>> pros refuse to give a guarantee on some repairs. Breaks are easier to fix
>> than cracks. If you are already planning on remaking the part anyway, no
>> big
>> deal if you screw up, right? Whats the worst that can happen, you get 
>> good
>> at it? Lord knows I haven't gotten good at it but I've made a couple of
>> decent repairs on my Titan that are working just fine thus far. As with
>> anything, you need to know when to call in a pro instead of try it
>> yourself.
>> However these days finding a pro that can weld cast is getting to be
>> difficult.
>>
>> Having said all that, I still can't solder and braze worth a flip. There
>> are
>> going to be some repeirs on the Titan to be made with either lead or
>> solder
>> and I hope to learn how. That tractor had the intake broke off at the 
>> head
>> once. It was put back on with the prettiest brass work I have ever seen.
>> To
>> top it off the guy wet around the flange and built it up for added
>> strength.
>> I have never seen brass with swirl marks in it like welding but this guy
>> did
>> a flawless job. And this repair took place before the mid '40's. The only
>> thing I did was to make a spotface for the bolt head and face off the
>> bottom
>> of the intake.
>>
>> John
>
>
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