Malcolm Jones Member 181 and Coupe owner

I read a post recently about a member considering buying a MIG welder which prompted me to write a few words. Unfortunately I haven’t found the same post again to reply directly.

A word of warning from a retired Metallurgist.

I’ve heard many phrases banded about when it comes to welding, such as Oh! I’ll just tack it on there, or It’ll be alright, just weld it up. But you can’t weld that stuff like that, yes I can, I’ve never failed to melt two things together yet.
If you know a thing or two about welding Metallurgy, such comments frequently send shivers down the spine.

Don't weld anything, particularly safety critical components, unless you are confident about it's "weldability", you could very easily end up with hazardous brittle structures in the "Heat Affected Zone" (HAZ) immediately adjacent to the weld or even cracks and we all know what happens then!. By the way, when welding steel with poor weldability, a small tack weld will be more of a danger than a proper weld run because whilst it still obviously melts the metal it will cool far quicker than a larger weld and hence give a greater chance of hardened hazardous structures.
Medium to higher carbon steels are the hazardous things to avoid unless you know what you are doing and can use appropriate welding procedures. Things made of very low carbon mild steel, body panels etc. are ok since there is not enough carbon (unless they are painted or greasy) to form hardened/ brittle structures but higher carbon steels such as high tensile bolts, suspension or steering parts are obviously far more critical and require appropriate welding procedures. It is far better to leave these well alone. Furthermore, in my experience, not all garage welders know a great deal about "weldability" so beware!.

This is worth knowing also