On Wed, 13 Apr 2011 22:15:14 -0700, "Steve B"
wrote:

My neighbor called me this evening about welding a cast part on the steering
mechanism of his tractor. It was dark, so I haven't been able to go out and
look at it. I shall look at it on my way out tomorrow on my way to Vegas.
He's going to check on the cost and availability of the part tomorrow, also,
then Friday, we'll pow wow and decide to try to fix or get a new one.

I have welded cast before, but never correctly. What I welded were
dissimilar metals, as in spindle tops on ornamental metal, which cracked off
easily when he kids hit them with sticks, or I bumped them during
installation I have never preheated, welded with Ni rod, and post heated.

I believe that if I clean this part, grind bevel the surfaces to get good
root penetration, preheat correctly, then postheat correctly, clamp to allow
for warpage, that I have a good chance of fixing it. How long it holds is
another matter.

Any pointers on: root prep, preheating temperature and length of time, arc
technique including length of arc, comparing this rod to any other rod that
may burn similarly, postheating and length of time. Is there any benefit of
gussetting the area for additional strength? What specific rod should I
get? How do I match rod diameter to work piece thickness? I have a laser
temperature gauge, but I believe this will be beyond the parameters of that
sensor. What temperature Tempilstick should I get?

I'll know more tomorrow when I see it, and will post a pic so you can have
an idea. He says the part is relatively easy to remove, and that would give
me the ability to clamp it on the bench and weld it in the flat position.

This will be a first for me, and a big deal if I can save my friend some
time and/or money. He's a great neighbor, and does tractor work for me for
fuel costs.

I do have some gas welding tips, and would this part be better gas welded
than arc? If I do that, what Ni filler rod should I get? Or can I get
electric rod, and use it for both types of repairs. A little voice tells me
no, but I'll ask anyway.

In the meantime, I can use just hypothetical advice until I get the
pictures, and a little better handle on this. If I can get all the info
pulled together, it looks like doing the actual welding Friday or Saturday.
Quick replies appreciated, as I'm going to pull the trigger on this Friday
or Saturday.

And is there any such thing as putting down the first pass the first day,
letting it cool overnight, buffing it, and then putting a beefy cover pass
the second day?

TIA

Steve

Heart surgery pending?
www.cabgbypasssurgery.com
Heart Surgery Survival Guide

I'd use oxy-acetylene, railroad rod and Ferro-flux. I don't know where
you'd find either railroad rod or ferro-flux these days, but I've
mended many broken cast iron pieces with gas, railroad rod and
ferroflux.