Ned Simmons wrote:
On Fri, 21 Aug 2015 09:03:21 -0500, "Terry Coombs"
wrote:

My little tractor has had a mishap , it put a con rod out the side of the
motor . Motor in question is a Kohler KT17 opposed twin . Since these are
rather hard - and expensive - to replace , I would like to repair the hole
by welding a patch over it . This unit is over 30 years old and oil soaked
,,, I've had reasonable success a couple of times , but nothing I'd write
home about , and I'm pretty sure the reason is I haven't been getting all
the oil out of the pores .
How long and at what temp do I need to bake this thing to be reasonably
sure I've got most of the oil out ? It will be degreased with solvent first
followed by a thorough scrubbing with detergent before baking . The part
looks to be die cast , which I believe means it has a fair percentage of
silicon in the alloy , which rod is recommended ? I have on hand 4043 and
5356 , but can get other if needed .
Or do I just need to bite the bullet and drop 130 bucks on a replacement ?
There is one on fleabay right now ... it's not that I don't have the money ,
I just hate to replace something that I can repair .

If the patch is 6061 then you definitely want to use 4043 wire. When I
repaired the cast door on my lathe I knew 4043 was the rod of choice
for the combination of 6061 and cast, but when I tried the 5356 that
was on hand I couldn't get it to work without cracking.

Back in the bad old days building marine hardware, 4043 was the rod of
choice and I don't recall ever having a problem welding the odd
casting.

I doubt you'll ever get the casting clean enough to avoid black smut
around the weld, but as long as it just needs to be reasonable
oil-tight and isn't highly stressed, you should be fine.

The inside & outside of the lathe door. I suspect someone tried to
pick up the end with a fork truck without paying attention to the
door. The patched-in pieces are a mix of original fragments and new
6061 material.
http://www.nedsim.com/news/DSCN0437.JPG
http://www.nedsim.com/Monarch61Rebui...arch61_16.html

How old is that lathe? It has an interesting look How toxic was the paint
you used?