mast repair

[mikee33]

yessirr and thanks for your patience with me. as i once again ask for help.It seems like drilling out two more 11/16ths holes plus larger for the inserts will weaken the area.. The doubler will help with that.

[Douglas]

After reading this thread, I decided to make Aluminum Flange Bushings, for the shroud tang bolts on my Forespar mast replacement.

The Forespar mast came with 1/4" X 2" diameter aluminum round disks welded to the outside mast wall with a 5/8" centered hole for the thin wall aluminum compression tube and a 1/2" tang ss through bolt.

I don't have a guideline to choose the outside diameter of the bushing that penetrates the mast wall for a ss 1/2" and or a ss 5/8" through bolt without allowing clearance for a compression tube.

I hope to use 2" outside diameter of the flange,,, which, will provide a wide enough flange apron to counter sink 2 or 3 flat head screws, to secure the flanged bushing to the outside of the mast wall.

I have been thinking that a 1" diameter hole in the mast would be sufficient size to spread the load of a 1/2" or 5/8" through bolt with a bushing to match the 1" mast hole.

Is anyone out there, willing to comment on these sizes or design ideas ?

Douglas

So nice to see that Brion is back on line, good on you mate !

[Bob Pingel]

Douglas-

I don't see a need to attach the flange to the spar with fasteners. The through bolt will hold the tang and bushing in nicely -- if the through bolt fails keeping that bushing in place will be the least of your worries.

I encourage you to checkout the aluminum/stainless bushing sandwich arrangement I described above. You can purchase this entire tang set/bushing arrangement through Brion for a surprising low price.

For reference, I would say the wall thickness in the bushings is 1/8" and the flange width is about 3/16" to 1/4".