[TheForge] Shrinking Stainless Sheet metal

[The Millers]

That was actually the recommendation I made to my partners in crime  
who created the "opportunity"
to shrink stainless.

In my industrial  world experience you don't weld any stainless,  
inconel, etc without backup gas,
and copper cooling plates o the back.

I provided the instruction to a larger scale shop once I showed how  
to do a sample section.

The project is to make a very large scale custom restaurant kitchen  
counter for an open kitchen.

It has curves, and radii and such and they wanted a rolled bull nose  
versus a flat front.

The plan called for cutting the sheet goods to the right size,  
radius, etc. and then rolling a piece of
stainless pipe to match. Stitch weld on an angle iron guide on the  
bottom side tack the back side of the pipe
and then stitch and eventually fill weld in the front edge of the  
counter top to the top tangent of the pipe.

In demonstrating the sample to the guys I used purge gas in the pipe  
for cooling, as well between the angle iron and the pipe,
along with copper back up plates.

The "forgot" those parts of the instructions and I am now working  
with them to correct the warps.

Next time I will be there for the set up.

Ray



On Jan 25, 2007, at 5:10 PM, mpaietta wrote:

>        If you purge the back with argon using a purge plate
> then your welds will    come out great.
>
>    Martin
>
>> Stainless has a 25% higher thermal expansion rate than
>> mild steel.   This is why it is such a pita to work when
>> you are welding  it in   thinner sections it will warp at
>> the drop of a hat it is also a poor   thermal conductor,
>> much worse than mild so the heating is localized   more
>> than with the mild and the thermal expansion is acting on
>> a   smaller area resulting in greater warping.  If
>>    possible keep beads   short and move to a different
> area
>> to do next bead and keep working   different areas around
>> whole perimeter till the complete weld is done   to keep
>> from getting too much heat in one area. This will help but
>> it   is still likely to warp.
>>
>> Jim
>
>>
>> On Jan 17, 2007, at 1:38 PM, Ries Niemi wrote:
>>
>>>
>>>  Theoretically, it should move much like mild steel, but
>>>  its so damn   hard to get to move, ever, that it seems
>> to be harder to heat shrink. >
>>>  ries
>>
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