How to Repair a Vise with Muggy Weld Cast Iron Rods

Muggy Weld customer Jon purchased our 77 electrode to repair an old cast iron vise and sent the following testimonial:

Yo! It’s working!!! Here is one side of the repair so far. I’m two steps below a beginner welder but was able to make it happen. I located the end of the crack with a 10x loupe then drilled a termination hole. Then I began to hog out a valley with a tungsten carbide Dremel bit. I only slightly warmed up the weld area with a map/oxy torch, final cleaning with a fine wire wheel, and slowly laid down the root pass 1/2″ at a time, peening with a punch between passes.

Here is the other side; the process was exactly the same. I encountered a bit more porosity on this side for whatever reason, so after the root passes, I ended up turning the amps down a bit and did some cosmetic fill work.

I found the weld itself is much harder than the old cast iron, which makes me think that this repair is now going to make this area even stronger than it was as cast.
Just like you guys said, the 77 is a really good color match to the cast iron once ground down.

Jon

Note: Jon stated that one side of the vise had more porosity than the first side. This is likely because the first side had been exposed to more contaminates than the other (dirt, oil etc), which soaked into the cast iron.

Tip

Heating the cast iron to around 400°F to 500°F may bake out some of those contaminates prior to welding.

Jon labeled himself a novice welder, but he repaired a large piece of cast iron that many professional welders would never attempt, thanks to 77 electrode.

Disclaimers:

Before using Muggy Weld products, please review and follow the welding safety guidelines provided by the American Welding Society (AWS):  https://www.aws.org/Standards-and-Publications/Free-Resources/#YourResources.

Additional product safety information is available at https://muggyweld.com/safety-guidelines

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Safety Data Sheets (SDS) are available upon request with purchase from MuggyWeld.com.

Updated 11/23/25

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