[Vwdiesel] Not VW, but diesel and relevant

[James Hansen]

A point of clarification:   When in the open air, the can (or owl) placed on a tractor muffler is called a SHED.  Once placed on the muffler, it ceases to be a can, and transforms into a shed. I'll have to try the owl shed out, sounds clever enough to work.

There are two ways to go about closing a hole like you have Val. Resign yourself to some warpage, but you can minimize it, maybe enough to get away without having to sand the mating surface of the manifold flat. 
Grind away all the thin stuff, get to clean cast iron, might make the hole bigger while you do that.  No biggy, the thin will fall away when you weld anyway, might as well start on where it is thicker.  You could use a nickel to close the hole if that is what you want, but a piece of scrap cast is okay too.  Preheat to a very dull red as viewed indoors, not in full sun.  In full sun, the red you see will be too hot to weld easily and the puddle tends to fall away.  Use whatever method, nickels, multiple passes, etc, but keep the part hot, that dull red heat. Propane tiger torch is great for this, I use one on bigger cast routinely.  Personally, I just use a mig welder with mild steel wire.  I said heat is critical, the only way you get away with using a mig.  After you are done, reheat the manifold to a normalizing heat, where magnets no longer attract to the steel, hold it there a bit, for a few minutes, just play the torch over the area and beyond keeping it RED, then cool slowly-  Wrap it in fibreglass insulation, bury it in vermiculite, dry sand, I've used zorb-all cat litter type stuff too.  Let it cool for the day- should take 8 hours at least.  I'll use something like 2 bats thick of R-40 fibreglass top and bottom, or a foot of dry insulation above and below.  Bringing it to a normalizing heat removes all welding stresses (lets the molecules shuffle around), and will only have residual stresses from different materials/thicknesses left after cool, which is usually inconsequential- most of your stress is built up from fierce weld heat on cool material, and subsequent regional shrinkage.
I use a mig for most cast repair, and a lot of heat on everything to a friend's thin little cast norwegian biscuit press from the 1850's to heads and blocks. Very rarely do I use nickel rod, but it does work well. Eutectic makes some cast rod that is great I think it was eutectrode 244, but lincoln would have similar. I keep some in the service truck for emergencies. Good luck.
-james

-----Original Message-----
From: Vwdiesel [mailto:vwdiesel-bounces at vwfans.com] On Behalf Of Val Christian
Sent: September-07-14 8:10 PM
To: vwdiesel at vwfans.com
Subject: Re: [Vwdiesel] Not VW, but diesel and relevant

Actually, I don't use a can...I use a plastic owl, hollowed out and reinforced to fit on the muffler.  I point the owl at the steering wheel and seat, and the number of bird droppings has approached zero.  

An idea for your open air garages...


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