wrote:

When I noticed a pop rivetted butt join on the mast of a new boat I
suspected a mast repair job? When asking the US mast manufacturing company
as to why a pop rivetted butt joint was present on a 45 feet long new mast,
they replied that the longest aluminium extrusion available was 40 feet
long. They also stated that it was standard practice in the industry to butt
joint the length of a mast after 40 feet. They said that their masts were
elongated by inserting an internal sleeve and securing the joint with pop
rivets. They also mentioned that other manufacturers were using butt welding
technique instead of pop rivets.

Maybe this is standard practice but it was an eye opener for me. As anyone
notices that before?

Standard practice.

I've had people who absolutely refuse to believe that our mast is all
one piece because he said the only boat where it wasn't that way was
carbon fiber.