Michael Horowitz wrote:
I"m familiar with the use of 'gauge' when describing sheetmetal.

I'm looking at 43.13 where it discusses welded patch repair. It says
make the patch out of material one gauge greater than that of the base
metal.

So I measure the base metal tubing (.035), go to the Inet and look up
a gauge chart and find that .035 lies between two gauge measurements.
And of course tubing suppliers talk in decimals, not gauge.

Faced with this difference in units of measurement, what approach do
you take? - Mike

I can't answer your question for certain (I'm not qualified). But-

I want to point out sheet metal gauge depends on the material (steel,
aluminum, etc). In other words, there are different charts for
different kinds of sheet metal (which is entirely different from wire
gauge sizes). I figure you know this, not everyone does. The Aircraft
Spruce catalog has this material referenced at the front of the metal
section. AC43.13 doesn't seem to have this info.

Anyway, I know what I'd do- to be conservative I'd pick the larger
measurement and go up one size higher than that. Of course that would
add even more weight