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Beware Mast Foot weakness

Posted: Wed Feb 08, 2017 8:09 pm
by Tenaciousgreen
Let me explain why!

Yesterday I went to my boat to tension my rigging correctly after a friend let me borrow his Loos gauge. Having loosened all shroud to change some shackle sizes to give me greater tightning options, I began to tighten the forestay, only to loosen by accident and the bottle seperated and the forestay flew.

It was a little gusty and the boom was up, turning to grab the flying forestay, I witnessed the mast fall aft. Fortunately no other damage done as my life lines took the brunt of the fall as it fell slightly to one side, but couldnt understand how the mast had fallen aft.

On check the mast step? I found the the mast had broken away from the foot which was still secured on the step. As can be seen the bottom of the mast just broken away, giving in around the rivets. Obviously over its long life this part of the mast must have weakened.

So today, I spent the afternoon reparing the problem, losing 13mm in mast height, having to cut away to undamaged mast and refit the foot, adding an extra rivet to the rear.
I just hope the repair and loss of mast height wont cause too many issues or affect performance.

In hindsight, whilst my fault, I am glad it happened like this, rather than having to potentially deal with it whilst underway in the event of a forestay failure!

Re: Beware Mast Foot weakness

Posted: Thu Feb 09, 2017 8:39 pm
by Yara50
Wow, you were very lucky to get away with only minor damage. I am guessing that as the shrouds were loose, the sideways fall jambed the mast foot and stopped it from pivoting. When I am dropping (rather lowering), the mast, the shroud tension holds it upright until I give it a nudge. However in your case the weight of the boom would be enough to get it going.

Shouldnt think a little bit off the bottom of the mast would make much difference, as there is plenty of boom height adjustment, and clearance from the end of the boom for the head of the sail.

Re: Beware Mast Foot weakness

Posted: Sat Feb 11, 2017 11:35 am
by Tenaciousgreen
Yes, I was very lucky. Lesson learnt without too much damage caused, although I have now noticed a crack in the 27MHZ antenna base. Hopefully it is still working, but it is an old one, so not too fussed other than cost.

Hopefully, get her out on the water next week, when this awful pommie like weather buggers off!

Re: Beware Mast Foot weakness

Posted: Thu Feb 23, 2017 10:08 am
by Ozzie
Glad you fixed the problem Rich and reused your foot. For newbies its good to know these fittings are still available through Keely Marine for anyone considering buying an investigator and wondering about part supply .

Probably not a major issue but Bob Keely when I spoke to him suggests using Duralac when fitting a mast base even though it's aluminium on aluminium there can be some electrolyte action between parts. (Available from whitw. )

Interesting side issue , while looking up the spelling for Duralac I found this gem on Ausfish forums.


'If you do use Duralac be very careful about getting any directly on your skin, and be very thorough with you clean up. Whilst it is very good gear for what it is intended for, it contains known carcinogen compounds. In some countries it is restricted for sale to non professionals because of this.
If in doubt check the US EPA site for reference to Duralac. For some reason it has not come under the same scrutiny here, same for MDF dust particles.'

Re: Beware Mast Foot weakness

Posted: Fri Feb 24, 2017 5:21 pm
by Tenaciousgreen
Thanks for thst Ozzie, I didnt use any compound and i dont think there was any on prior to my repair, so I am not too concerned.
Got her out on the water twice this week and there is no noticeable difference to performance. So all in all, pretty happy considering.