Measuring Fillet Weld Size with Incomplete Fusion

Date 05-17-2018 13:59

If there is incomplete fusion in the root, the weld fails. The weld must exhibit fusion to the root, but not necessarily beyond the root.

Al

By welderbrent (*****)

Date 05-17-2018 17:45

The question is not, 'how do you measure' but instead should be, 'WHY WOULD YOU measure' a weld leg when it is obvious the fusion is not to the root?

If there is good reason to measure the leg, it would appear obvious you would only measure the area that displays fusion. But, per most any code and application I am aware of there would be no need. It failed the moment you were able to determine fusion did not go all the way to the root.

He Is In Control, Have a Great Day, Brent

By dbatten Date 05-17-2018 19:00

Thanks for the responses.

I'm aware that the weld fails due to the incomplete fusion regardless, but am filling out a report (poorly written) that lists each acceptance criteria of 4.9.4.1 separately. I was unsure of what to indicate for 4.9.4.1 (3), "Minimum leg size shall meet the specified fillet weld size", as a measurement is implied in the report.

Simply say "N/A Due to incomplete fusion" and call it a day or actually provide a measurement of only the fused area as Brent suggested?
This is probably just a matter of opinion at this point.

By Steelslinger (**)

Date 05-17-2018 20:01

I would vote for "N/A - Incomplete Fusion of the Root"

By welderbrent (*****)

Date 05-18-2018 14:27

Good Day,

Lets back up and answer a couple of your other questions as well as the most recent one.

So, all fillet welds are actually measured by throat dimension. That is how the Engineer has calculated the required strength of the weld. And, it is usually this measurement that is on the engineered drawings for proposals and bids. Then, the detail calls out the welds per leg size based on the D1.1 or other applicable code equation for such since this is the best, fastest, easiest way for welders and inspectors to check weld size. We ASSUME it is the correct size based upon all the previous generations of successful welding with a given process to a specified WPS with welders proven qualified to get fillet welds with fusion to the root.

SSSOOO, does the answer change if the weld is concave instead of convex? NO. Only the part of the fillet weld gauge used to inspect the weld changes in order to make sure the correct leg and thus throat dimension is achieved. The concave gauge is using both a determined throat and leg to make sure it is of proper size; not really sure I described that well but it works.

Now, if you really want to include a dimension on the report to illustrate how poorly the weld was fused, go ahead. Nothing says you can't. But, your statement that it is N/A or just 'Rejected for Incomplete Fusion to the Root' is adequate.

The code isn't going to tell you how to fill out the report and there are some items that are difficult to word on a standard report. Too much detail can mess things up. Use a Supplemental page and put something like 'See Note 1' on the report. Then place that note on the other page.

He Is In Control, Have a Great Day, Brent

By Lawrence (*****)

Date 05-18-2018 15:01

Here are some slides that speak to Brent's assertion that fillets are measured by throat dimension.

This is true... An isosceles triangle from root to toes is used for the measurement.

Calculations of the leg length is applied to flat or convex fillets and marked on the leaf gage.

Calculations of the actual throat are applied to a concave leaf gage, with a mark that is equivalent to leg length on a convex gage to avoid confusion and calculations by the inspector.

Hope I said that right.