From: Fred Martin (mung@in-touch.net)
Date: Thu Jan 13 2005 - 10:22:21 PST
Sometimes when you try to weld cast iron that has heat applied to it
such as and irons (sp?) for a fireplace ...you find that the good has
been burned out of the metal and when you heat it to the temperature to
weld...the parent metal just goes to oblivion. This applies to electric
and gas (accetylene) welding. The general accepted method to repair an
exhaust manifold (in my mind, if possible) is to use furnace cement. And
it will eventually crack...but maybe you could put a sheet metal band
around it like is on some generators to help prolong the repairs life.
Furnace cement is available at the better hardware stores...muffler
cement from the auto parts stores seems to be the same thing. At the
temperatures that a diesel engine runs...the manifold temps can get
pretty close to brass and bronzes melting temperatures...in my
opinion. Fred Martin
Bob Ternes wrote:
>Boy. I had a big post typed up but deleted it in
>retrospect, since welding to cast is voodoo tech.
>You should know what sort of casting it is, and
>then understand the need for preheat and slow
>cooldown and a whole heap of techniques.
>
>Welding to cast is an art. I'm not saying this
>because I make beer money at this on the side
>(I'd say the real art is getting other people to
>pay for your beer in the first place), but
>because to explain the tech on it for 100%
>positive results would be difficult. How to
>identify different casting materials, when to
>grind out, when to v and when to burn a hot
>autogenous weld with filler to keep the puddle
>going, what to look for when preheating, how to
>stop porosity and what alloy or hi nickel rods to
>use when, when you want to pin and butter bigger
>pieces, this is a whole chapter. Then there's
>always the option to braze or do that powder
>stuff, which as a TIG guy I instantly mistrust
>(I'd rather run something like silicon bronze rod
>and 7 amps with my torch than braze to join even
>something like copper air lines and steel). ;)
>
>Doesn't matter anyway (is a "moot" point in the
>proper contemporary parlance of the list), since
>you want to keep the mani on the vehicle anyway.
>Bottom line is that you should take a look at
>"Pyro Putty" if you want to do a cheap repair on
>the vehicle. Probably will hold, and even if it
>doesn´t, well, you end up pulling the part for
>the welding repair you would have ended up doing
>anyway.
>
>Cheers
>Bob Ternes
>Semi Professional Differential Shaver
>
>--- 42Ford GPW <ilovejeeps@hotmail.com> wrote:
>
>
>
>>What is the best way to repair exhaust manifold
>>cracks?.....by this I mean a
>>repair done by
>>still keeping the exhaust manifold on the
>>engine!
>>
>>Is JB Weld still the best option ???
>>
>>Thanks
>>
>>Mike Curtis
>>1942 GPW(2) 1943 WC-52
>>1942 MB 1943 WC-56
>>1944 MB 1951 M37
>>1951 M38 1963 M37-B1
>>1955 M38-A1 1968 M35-A2
>>1972 M151-A2
>>1942 OPEN CAB LWB CCKW
>>FORD GPW SPARE PARTS/BOXES/TAGS, ETC.
>>
>>
>>
>>===Mil-Veh is a member-supported mailing
>>list===
>>To unsubscribe, send e-mail to:
>><mil-veh-off@mil-veh.org>
>>To switch to the DIGEST mode, send e-mail to
>><mil-veh-digest@mil-veh.org>
>>To reach a human, contact <ack@mil-veh.org>
>>
>>
>>
>
>
>===Mil-Veh is a member-supported mailing list===
>To unsubscribe, send e-mail to: <mil-veh-off@mil-veh.org>
>To switch to the DIGEST mode, send e-mail to <mil-veh-digest@mil-veh.org>
>To reach a human, contact <ack@mil-veh.org>
>
>
>
This archive was generated by hypermail 2.1.4 : Sat May 07 2005 - 20:39:27 PDT