What kind of equipment do you weld with Jerry? How big of a gap
is acceptable? Is the acceptable gap size different for tig?

Paul Lamar

Jerry Hey wrote:

In building an engine mount I weld with MIG, TIG and Oxy/Actl.  I use
a little 110V MIG to tack weld the tubes in place. Then in one area
where the clusters are very hard to heat adequately with the torch, I
TIG weld.  The rest of the engine mount is Oxy/Act welded. The reason
I weld with Oxy/Actl is that it is often very difficult to get into
position with the TIG,  while having to have  one foot of the
pedal.Working around an engine mount  under the best of circumstances
requires a contortionist even without having to worry about the foot
pedal.

The subject of "fitting" is controversial.  Tony Bengelis (sp?) said
once to avoid gaps of 1/16 or 1/8.  Well, in reality  1/16 is easily
welded either by TIG or Gas.  And 1/8 is hardly impossible but you
will end up with wider, less attractive welds.  Of course, zero gap
is the best but you will not always be able to achieve it.  In
welding less than perfect fits, use a heavier rod.  I usually weld
with 1/16 rod, but use  3/32 as well. I agree with the post that said
you should complete all welds with the engine bolted in place and the
mount bolted in place. If you don't your final product may well be
unusable.    After each weld spend a little time with  the torch
stress relieving, the slow cool down seems to lesson warping quite a
bit. Jerry

Thanks Jerry. Sounds like very invaluable advice from an experienced
aircraft welder. Looks like I need to get my torch up and running
as well as my tig. Confirms my gut feelings on using the mm jig to hold
things in place while I weld it up with the tig. If it looks like I am 
doing a bad job I can load the whole thing in the back of 
the mini van and take it down to my local tig welder.

Paul Lamar
 
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