Aluminum Boom or Mast Cutting/Shortening
Boom shortening - As practiced by Charleston Spars, Charlotte, NC - 704 597 1502 - 16 Oct 01
Cutting F-Section Boom - has four internal lines in the boom
Can cut either end, may be easier to cut the back end
Stuff the lines into the boom and pull back out after reinstalling the boom end fitting
Make sure the lines are not crossed or tangled!!!
Pull them back out one at a time
(could use a fish line taped to inside of boom to keep lines properly oriented)
Existing 1/4 inch rivets - need big hand held rivet machine to install rivets
Can reinstall end using machine screws instead of rivets Note: used monel rivets on Crumpet's boom.
Machine Screws: 5/16" (diameter) 18 (threads per inch) 1/2" (length)
Drill tap for these screws
Tap through the boom into the casting
(drill new holes into casting - can't hope to align with existing holes)
Apply anti-sieze compound when installing screws
Use "round head" or "pan head" screws - whatever looks best to you
Use a saber saw to cut the aluminum
To get a straight line around the boom - get a wide (eg 4" wide) belt and cinch it tightly around the boom - then scribe the line at the edge of the belt to get a smooth straight line all around - could use thick paper or plastic to get the edge with a belt over that to cinch it tightly. (Note: used sheet aluminum flashing that worked very well for this purpose).
Protect the surface of the boom from the saber saw kicking out and scratching it, by taping the boom surface - could use two or more layers of electrical tape
Use paraffin wax on saber saw every couple of inches to keep it from loading up
Cut about 1/32" away from finish line, and file down to the finish line
Can use coarse wood rasp on aluminum - won't load up with shavings.
