[T3] Invasion and Post Invasion Repairs

[Jim Adney]

On 9 Aug 2018 at 9:31, John LaFrancois wrote:

> Just thinking out loud here, I haven't checked this, but is it possible
> that the most of the bar is hardened, and the ends are softer?  Or the
> machining on the ends of the bar may have removed most/all of the
> hardening in those areas?  I would think that one might be able to keep
> some/most of the hardness after welding spring steel if the weld areas or
> heat were isolated, and quenched while still hot.

I checked the middle of a junk bar, and it wasn't hard there either. That 
means that the welding doesn't have to be much of a concern. Our welder, 
Bill, suggested that we let the welded end of the bar cool very slowly in his 
bucket of lime powder. When I came back after an hour, it was still quite 
warm to the touch.

The filler rod he used was ER70S-2, done with TIG. This left a nice bead 
that I was able to file easily.

So far this appears to be working quite well, so it looks like a gentle weld 
and slow cool is the way to go.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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