Re-rigging the mast to specs

Moderator: GreenLake

Re-rigging the mast to specs

Postby fatjackdurham » Sat Sep 02, 2017 10:38 pm

Hi all, it's been a couple of weeks. I've been busy with other projects, but today I spent the whole day re-rigging the mast to try to correct the poor job a previous owner had done adapting a mast to this boat.

Based on the North Sails tuning guide, I determined that my mast was a little too long. I trimmed off 8 1/2" from the bottom, and reattached the tabernacle. Then, I moved the forestay and shrouds up by the same amount, putting the top rivet of the strap at 15' 1", and the pin of the shrouds at 14' 10". The only difference was, I attached the forestay at the same height from the tabernacle as the shrouds. The tuning guide specifies that the shrouds should be attached 15' 3" above the base of the mast at the cuddly bulkhead, but it doesn't say if that is the top of the strap, the pin, or the point where the strap angle meets the mast. Before, the forestay had been about four inches lower. I wasn't sure if this was correct as the tuning guide only specifies how high to attach the shrouds, but doesn't mention the location of the forestay.

Well, as you can probably tell from the photo below, I have a bit of forward rake. I measured the distance from the masthead to the stern gunnwhale and it was 26' 1", about a foot longer than the tuning guide specified.

Besides this change in mast points, I also fabricated a topping lift, based on the article. I made the lifeline with swaged eyes myself, but its a bit short. Not a problem, but the line I used to rig it to the boom is also to short, so I am again going to have to buy more line.

BTW, the measurements guide specifies a 44' main sheet. Really? My new one is a little short at 27', but 44' seems a little too long. Thoughts? I was going to go with 35', but I wanted to ask your thoughts.

Anyway, back to the point. After the trig session shown in the second photo, I have determined I should raise the shroud attachment point to 15' 3" from the base of the mast at the top rivet, and lower the forestay attachment by 2" to 14' 11" at the top rivet. Doing this should set my rake at 25' 1" to the stern from the top of the mast (well, as far up as the halyard can hoist my tape measure, anyway.).

If I can find more stainless rivets, I'll do it tomorrow. But, I have ransacked the three nearest TractorSupply stores near me, and none have 3/16" x 1/4" any more. The fourth store within driving distance will be my target tomorrow. Otherwise, I'll have to order them online and wait.

And, three weeks since I sent my motor in to get fixed. It needs a new carb. I don't understand why it's taking so long. I know it's old, but lets be real. There isn't a product on this planet that can't be ordered online and delivered in a week.

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Re: Re-rigging the mast to specs

Postby fatjackdurham » Sat Sep 02, 2017 10:44 pm

BTW, the two tone sail is just a photo processing error, they are intact all white.
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Re: Re-rigging the mast to specs

Postby GreenLake » Sun Sep 03, 2017 2:14 am

If you really end up with a forward rake, I'd expect you'd be very disappointed with your boat's performance.

Remember to measure twice (better thrice), drill once...
~ green ~ lake ~ ~
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Re: Re-rigging the mast to specs

Postby fatjackdurham » Mon Sep 04, 2017 6:42 pm

Ok. Moved the for stay mount down three inches, took up about an inch and a half on the shroud turnbuckles, and moved the spreaders up five inches. Now my rake measures 25' 7", which will have to do until I can get out on the water to test.

One issue I noticed is that even with the stays tight, when I tug out on the forestay, it moves and I can see the mast tabernacle flex and even the deck flexes a little. I know it should't, because the mast goes through the deck down below. And it's not easy, it takes a good tug to do, but I am wondering about it. I am not concerned. The stays are tight enough and I had to use the winch to attach the forestay, so I am confident it won't be a problem.

Sorry for the bad picks. I used my crappy iPad. Here is the new outhaul tackle and the topping lift tackle. I am very pleased with both. Eye splice on 3/16" line was hard....

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Re: Re-rigging the mast to specs

Postby DigitalMechanic » Mon Sep 04, 2017 9:32 pm

It looks like your making progress. If you got your standing rigging pre-measured (say from DR Marine), and you can attach it to you mast, then you are half way there. I imagine all specs are from the partners (top of the cuddy hole where the mast pokes through). Many of our boats have been de-masted along the way of their 40-50 year journey, and the keelson has been shortened to fix tears from those delightful incidents. Point is that the height does not have to be spot on, just close enough. I lost a mast a year or so ago. I was lucky enough to fish it out of the river and re-attach it (god bless the crab fisherman that laid the trap I got stuck on, but that is another segue story, lol). I had to cut the keelson back a few inches to remove the damage and re-attach the tabernacle. Ultimately I put a wood block in the bottom of the boat sandwiched between some castings, which brought the heigh back close enough to spec to work the turnbuckles to apply the desired tension I want on the rig. It has held up thus far.

You have the turning guide so you should be able to get it good enough to sail on the trailer. The mast rake should be 25+- an inch from the top of mast to the transom. You can measure the port/starboard lean by grabbing the main halyard and walking from side to side of the boat and marking with your thumb. When all said and done you will want to make sure that there is enough tension on everything so that it places the mast even starboard/port and 25ish inches from transom to top o' mast, while introducing 1" prebend. Prebend can be measured by taking the main halyard and holding it to the gooseneck, and then measuring the distance between the halyard and mast at the spreaders height. If you got an inch, you are good to go.

More detailed rigging explanation here...

Hope you get it licked and can sail soon! She is a nice looking boat!
Last edited by DigitalMechanic on Mon Sep 04, 2017 9:52 pm, edited 1 time in total.
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Re: Re-rigging the mast to specs

Postby fatjackdurham » Mon Sep 04, 2017 9:44 pm

Thanks. Good info. Getting there. I am hoping weather will let me sail my ne more time this year.
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