Question about a weld inspection in Mobile that changed my mind on root passes

Ivan Butler · 2026-03-13T03:20:12.256775+00:00

An old hand from the union hall in Mobile told me my root passes on 2-inch schedule 80 were 'too hot and fast, you're just making a pretty bead over a cold crack.' I started using a lower amperage and a tighter arc gap, and the difference in the x-ray results was clear. Do you think a slower, cooler root is always better for high-pressure pipe, or are there times to run it hot?

bennett.james6mo ago

My old foreman in Baton Rouge made me run a 7018 root at 85 amps on 3-inch pipe. The slower fill just held up better under pressure.

4

laura_scott7mo ago

Heard a foreman say a cold root is just a crack waiting to happen.

2

morgan5747mo ago

@laura_scott, but a perfect root needs the right heat for the metal's thickness.

-1