72 and 77 Electrode Cast Iron Exhaust Manifold Repair Kit
$69.00
The Muggy Weld Cast Iron Exhaust Manifold Repair Kit saves you time and money on exhaust manifold repair. Using our repair kit, you can weld the manifold and make the repair without having to disassemble it first. If you can reach the crack, you can fix it while the manifold is still in place.
This kit provides an affordable alternative to repairing an exhaust manifold that could save you hundreds of dollars. There is no special heating or cooling required when using these rods, and no need to remove your exhaust manifold prior to making the repair. These qualities make this the ideal repair kit to have on the road with you if you’re trucking, RV-ing, or just traveling in general.
Why Choose the Cast Iron Exhaust Manifold Repair Kit
Repair in Place: No need to remove or disassemble the manifold when the crack is accessible
Burnt Cast Iron Capacity: Start with 72 rods to bond to heat-affected or contaminated cast iron surfaces.
High-Performance Finish: Use 77 rods to complete the weld with strong, crack-resistant, porosity-free material.
Efficient Welding: High-efficiency weld metal transfer prevents electrode overheating.
No Special Preheat or Cooling Required: This kit is designed save time and work with ease.
Stretch Tolerance: The weld deposit stretches more than nickel welds, helping reduce cracking.
Versatile Applications: Works on cars, RVs, trucks, buses as a mobile repair solution.
Kit Includes
The Cast Iron Exhaust Manifold Repair Kit includes both 72 Burnt Cast Iron Electrodes and 77 Cast Iron Welding Rods. The quantity of each depends on the diameter you select:
Store in a dry area at room temperature. Keep rods sealed in their original packaging or an airtight rod tube, to prevent moisture absorption. When stored properly, the electrodes maintain full performance and weld quality indefinitely.
How to Use the Exhaust Manifold Repair Kit
Clean the Repair Area. Begin by removing all grease, paint, rust, and debris from the cracked or damaged section of the manifold. A clean surface ensures a more effective bond.
Determine Accessibility. If you can reach the crack, you can repair in place without removing the manifold. This saves time and avoids the risk of breaking bolts or damaging gaskets.
Anchor the Weld with 72 Electrode. Start the repair with 72 Burnt Cast Iron Rod. Strike an arc and maintain a short arc length to achieve proper penetration.
Use Proper Technique and Temperature Control. Avoid long arcing or excessive heat buildup, which can distort the manifold. Instead, make small overlapping beads, allowing each to cool slightly before continuing. If you’re welding a long crack, weld an inch or two at a time and alternate ends of the crack to distribute heat evenly.
Remove Slag Between Passes. After completing a short weld segment with 72, chip and brush the slag away before switching to the 77 rod. This ensures a clean bonding surface for the next layer.
Overlay with 77 Electrode. Once the base layer with 72 is established, continue with 77 rod to complete the repair. The 77 rod provides a strong, porosity-free weld that resists cracking and can stretch up to 300% more than nickel rods.
Control Cooling for Best Results. Allow the repaired manifold to cool slowly in still air. Do not blow air, fan-cool, or expose the parts to drafts. Fast cooling can cause cracking. The ideal cooling process is natural and gradual.
Final Steps. When the manifold is fully cooled, remove remaining slag and inspect the weld. Grind or blend the repair if desired for appearance or fit, but machining is generally unnecessary.
Reinstall or Test the Manifold. Once the repair is complete and cool, reinstall or run the engine to confirm there are no leaks. The finished weld will remain strong and flexible under repeated healing and cooling.
Common Applications
Fixing cracked or leaking exhaust manifolds on cars, trucks, RVs, and buses
Repairing manifolds that have been damaged by excessive heat or thermal cycling
On-the-Road Repairs to prevent breakdowns or to finish repairs without full manifold removal
Frequently Asked Questions
Can I repair the manifold without removing it?
Yes. If the crack is reachable, you can use the kit without disassembly.
Why use 2 different rods (72 and 77)?
72 bonds to dirty, burnt, or contaminated cast iron, 77 is used for a strong overlay that resists cracking.
Do I need to preheat the manifold
No special heating is required in most cases.
What polarity should I use for the repair?
DC reverse polarity (electrode positive).
Can I use this kit for nodular or ductile cast iron?
The Exhaust Manifold Repair Kit provides a complete, reliable solution for repairing cracks in cast iron exhaust manifolds. Use 72 to anchor into burnt or contaminated areas, then finish with 77 for a durable, crack-resistant weld. Repair in place, skip removal, and get lasting results on a variety of vehicle types.
California Proposition 65: WARNING: This product contains chemicals including [Nickel], which are known to the State of California to cause cancer. For more information, go to http://www.P65Warnings.ca.gov
Exhaust Manifold Kit includes:77 is a premium electrode that produces welds which are high strength, crack resistant, and porosity free when applied to a wide variety of cast irons. The special tri-metal core wire has a high current carrying capacity and the specially designed coating converts the impurities of the base metal into slag instead of being trapped in the deposit. The high deposition rate creates an extremely narrow heat affected zone– a feature suitable for all weldable cast irons requiring post weld machining. 77 cast iron welding rods are softer than nickel rods, and have unique properties that allow the cast iron welds to stretch and elongate up to 300 percent more than other rods, which helps prevent the base metal and weld from cracking in the process. Key Features:
High efficiency weld metal transfer eliminates electrode overheating
Crack-resistant formula eliminates the need for pre-heating or special cooling
Ideal for heavy machinery, trucking, bus lines, automotive, marine, and RVs
Repair cast iron exhaust manifolds, engine blocks, industrial machines and more
______________________________ 72 is a nickel-iron non-conductive electrode formulated to join dirty and contaminated cast irons. This universal electrode can be used to weld a wide variety of malleable, ductile, and nodular cast irons. In addition, it is ideally suited for the repair of defective or cracked malleable iron castings. There are occasions in industry where exceedingly dirty cast iron is encountered. 77, which bonds well to most cast iron does have a limitation. Since 77 has controlled penetration, which is ideal for non-cracking and machinability, it may not be able to bond exceptionally dirty cast iron. 72 should be used for this application. It has a high penetration, can anchor deep into the subsurface of dirty cast iron, and seals in porosity generating contaminates prior to finish welding with 77. 72 is used for a cladding operation, then the weld is completed with 77.Key Features:
Flux coating does not side arc even after being heated
