How to Weld Dirty Cast Iron Parts with 72 Electrode

Weld Dirty Cast Iron Parts with 72 Burnt Cast Iron Electrode

Brandon at Zeigler’s Welding in Olympia, WA, uses Muggy Weld 72 electrode to weld a dirty, heat-affected cast iron manifold.

This manifold has extensive damage, the flange was broken off and tack welded in place. Most cast iron manifolds aren’t nearly as bad, but you will run into this from time to time, and when you do, make sure you have Muggy Weld 72 electrode in stock—most cast iron electrodes will just ball up and roll off while welding.

Maintain a close arc and weld no more than one inch of the cast iron at a time. Preheating the cast iron to roughly 200 degrees F prior to welding will remove the moisture in the weld area, and will help the weld cool slower which is imperative in welding cast iron exhaust manifolds. Peening the weld immediately after will enable the weld to stretch and relieve the stress between the cast iron part and the cast iron filler rod.

If cracks develop after welding, Muggy Weld 77 electrode can be applied on top of the 72 weld to eliminate further cracking. Both 72 and 77 can be used as a TIG rod, simply soak the rods in a bucket of water for about 5 minutes to remove the coating for TIG welding.

Muggy Weld 72 cast iron welding rod is recommended for non-machinable welds on exhaust manifolds, furnace grates, cast iron stoves, machine bases etc., as it has a high penetration, can anchor deep into the subsurface of dirty cast iron, and seals in porosity generating contaminates.

After inspecting the weld, the welder, uses additional 72 electrode to bridge a gap in the repair. 72 cast iron welding rod can also weld cast iron to steel, in addition to repairing dirty cast iron parts.

Another great attribute of 72 cast iron electrode is its ability to be used in all positions. This makes 72 an ideal choice for maintenance welding applications.

Brandon Harvey, Foreman, Ziegler’s Welding machined the exhaust manifold after completing the weld and stated “we machined that weld right away, no cracking under the surface…It works better than other products we’ve used”

Thanks, Brandon, and everyone at Zeigler’s Welding in Olympia, WA


NotePlease observe all AWS Safety & Health Guidelines when using Muggy Weld products.