The evolving riddle of Duet’s mast rake – Part 3

June 26, 2014 at 8:42 pm

So Duet’s mast was too raked and her forestay and roller reefing foil was too long… and then one evening I remembered that on a historical survey in her paperwork there was a picture of the foot of her mast showing corrosion, and there was a receipt from a local yard for removing 25mm off the bottom of the mast.  (This survey had been done in 2011 and had shown up a few issues that had been rectified before sale).

My hunch was then that her mast had been shortened to remove the corrosion but her rigging had not been readjusted correctly…

Survey Mast Corrosion

This is the picture from the survey of her mast corrosion before it was fixed.

So I contacted the previous owner who did confirm that this was the case and the work had been carried out by a professional yard.  Apparently 2 inches were removed from the bottom of the mast, and rather than adjust the rigging, the chainplates were shortened by the same amount… except that the forestay has no chainplate and couldn’t be shortened.  So they left it long!  The previous owner also admitted that he never sailed her again after this work was completed.

Professional Repair

This is a picture, also taken from Duet’s file, of the repair immediately after it was done. The yellow stuff is Duralac to help prevent further corrosion.

At least this confirms what I kind of have already figured out!  As mitigation on my part, when I bought Duet she was on the hard in a very tightly packed yard and it wouldn’t have been so obvious to see that she was so raked.  I did start to notice it when she was in the marina but thought it might have been due to ballast (she did have a very heavy engine hung on the transom) but it was only this year when she was out on the hard again at the Academy that it really started to niggle me and I put it together with the weather helm.

However, the previous owner did also give me some advice for reducing the weather helm:

  • Keep weight out the back end, keep the prop out of the water (but he had the outboard mounted on the transom and I’ve put it back in the well)
  • Reefing the main first (this will move the centre of effort forward)
  • Ease the mainsheet (again this will move the centre of effort forward)
  • He also recommended new sails, apparently he’s got a fully battened main on his new boat which made a big difference (this is quite an expensive option though)

Note:
I’ve done some research on this now and it seems that taking off a few inches of corrosion on the bottom is a really common, and is the correct way to fix this issue. Apparently if a mast fails it usually goes further up around the spreaders.  As long as the mast is sat in the shoe correctly it’s not a weak danger point. So that gives me peace of mind at least.