Frank Boettcher wrote:

On Tue, 04 Jul 2006 19:14:01 GMT, 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?

It's been many years, but I used to work in an aluminum extrusion
plant. We certainly were not limited to 40' max length.

Frank

On our type of boats, the limiting factor was shipping not
manufacture. The manufacturer used whatever they could get the best
price on and there are many different mast profiles that they used.
Some of the boats have the two piece mast and some do not.

Most of our masts were either 56 feet or 65 feet above the waterline,
and they were keel stepped so you need to add another 7 feet or so
onto that.