boom vang fitting

[Jimlad]

kryptonite is hull 1620 and has a rigid boomvang attached to the mast by a plate and secured by eight bolts in two two parallel sets of four each.  I've noticed that one of the bolts is missing and two others turn freely when I try to tighten them.  I have a horrible feeling that the nuts are secured inside the mast and I'll have to drop the mast to securely reattach the boomvang.  I reckon the problem might have been caused by an uncontrolled gybe in the past.  Whatever the cause, it needs to be fixed.  Anyone got any views?
Cheers
Dave.

[Jim Price]

I cannot speak for your installation but most of those items attached to the mast are machine screw / bolts that are threaded into the mast itself.  Installation usually consists of drilling the pilot hole and the tapping the threads in in the mast for the bolt.  Otherwise you would not be able to reach up inside the mast far enough.  I guess it is possible with a deck stepped mast to have through bolts with nuts on the inside for the lower atatchments.

If your bolts are tapped into the mast and loose then the threads are stripped in the mast.  You will have to remove the plate and re-tap the loose fitting mast holes with slightly larger size bolt size to have secure fitting.  This may mean slightly enlarging the holes in the plate for those specific bolts.

If you are dealing with bolts and nuts, then the mast will have to come down (or up to get to the bottom).   

[Bruce Hanson]

Dave, a product called a HeliCoil is the standard repair to damaged threads here in fresh water, not sure if it is a accepted pratice in salt. It is a anodized piece that looks like a spring with the inside matching the size bolt you need and the outside is a nonstandard oversize diameter which matches a supplied tap. The kit comes with a installation tool and good directions available in most auto part stores here in the US.

[Ron Hill]

Jim : As mentioned you'll have to compress the vang and remove it.  Then back out the machine bolts and note which ones have stripped threads.  Those that are stripped need to have the next size larger bolt tapped and re threaded. 
Be sure to coat all of the bolt threads with grease or lanacoat when you reassemble.