Spreaders/Spreader brackets

Moderator: GreenLake

Spreaders/Spreader brackets

Postby Adept » Sun Jul 24, 2016 8:35 pm

Hello all,

My mast is one of the mast jack style meaning that there is nothing at the bottom to prevent the mast from rotating (unlike the later models that fit into a metal cast step). When I bought the boat the spreaders had pins going through the mount points closest to the mast, but no pins on the outer holes to keep the spreaders locker in place. When I set the mast up I thought about putting pins in the outer holes, but it seemed as having pins in both would put a lot of backward force on the spreader bracket.

The pics below show what's happening on the water - please excuse the bird droppings on the deck. The last pic illustrates my concern. The path of the stays is to the aft of the mast. If the second pins are put into the bracket locking the spreaders forward, there could be a lot of strain on the bracket or the aluminum spreaders.

On my previous boats had a cast mast steps and spreader brackets that would allow the spreaders to pivot freely to allow them to align to the spreader path.

Has anyone experienced something similar? Advice?

2233
2234
2235
2238
Adept
 
Posts: 14
Joined: Sat Mar 12, 2016 8:55 pm

Re: Spreaders/Spreader brackets

Postby jeadstx » Mon Jul 25, 2016 2:02 am

D&R Marine sells the heavy duty spreaders that have the squared end to go in the bracket with a slot for the stay to be secured with a wire on the end, They also sell the mast step casting.

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
jeadstx
 
Posts: 1216
Joined: Tue Jul 08, 2008 11:10 am
Location: Dripping Springs, Tx

Re: Spreaders/Spreader brackets

Postby GreenLake » Mon Jul 25, 2016 4:24 am

I have a mast jack, but have never observed mast twist. The mast is roughly egg-shaped in cross section, and the mast partners (that is the opening in the cuddy) has fairly limited tolerance. Whether that is factory original or whether some previous owner added a bit of fiberglass to make that opening more form-fitting, I don't know. The fact is, the fit is so precise that the mast won't drop unless it's nearly perfectly aligned.

My boat has what Rudy from D&R Marine calls "Javelin" spreader brackets. They are completely free to swing both forward and back. There's nothing wrong with that, because the load on the spreader should be in line with the spreader. In my case, the problem is that the hinge only allows movement in the horizontal plane, while the spreaders get some off-plane loads (the hinge isn't strong enough to handle those, and breaks - it's just a pin through two holes at the inboard end of the spreader, and the holes give out).

I don't know hat the "casting" is supposed to fix. The bottom of my mast ends in a casting that has a circular hole, which takes the threaded rod that constitutes one half of the mast jack. The other half is the circular nut on which the mast casting rests, and which can move up and down to tension or de-tension the rig. Nothing there will prevent any twisting.

I would first see that you eliminate the mast twist. If you do have a mast jack that you use for tensioning the rig, then the place to fix the angle of the mast is the partners. Mine have about an inch of laminate; that's enough material to apply something like a structural filler and then sand it to shape. (3M High Strength Marine Filler would be up to the job I think, as would some of the epoxy pastes. The 3M product is fiber-reinforced and polyester-based, which makes for a quicker cure). All you would be doing is reduce the opening to match the mast more precisely at the correct angle.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7137
Joined: Mon Jun 18, 2007 3:54 am

Re: Spreaders/Spreader brackets

Postby TIM WEBB » Mon Jul 25, 2016 11:04 am

Every DS manual/diagram I've ever seen shows only one clevis pin per side, in the hole furthest outboard:

https://daysailer.org/Manuals
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
TIM WEBB
 
Posts: 1208
Joined: Wed May 18, 2005 10:28 pm
Location: RIVERSIDE, CA

Re: Spreaders/Spreader brackets

Postby Adept » Tue Jul 26, 2016 10:40 am

Thanks for the responses.

The partner has some space around the mast - I suppose I could use cedar shims as a temporary measure to reduce the twisting.

I'll look into replacing the spreaders, but after buying the boat, fixing her up, buying various new fittings and new sails, new investments are being postponed to next season :cry:
Adept
 
Posts: 14
Joined: Sat Mar 12, 2016 8:55 pm

Re: Spreaders/Spreader brackets

Postby DigitalMechanic » Tue Jul 26, 2016 6:58 pm

My mast is on a tabernacle, but the holes the screws go through in the cuddy floor are worn out which allow the mast to rotate left or right a bit. Agreed with GL that the shape and partners are egg like. So, the movement cannot be too much, at least for me it cannot. I run close to 200lbs of rig tension on the side stays, and notice that the mast really does not move once the mast is up and the rig is tensioned. In fact I usually hand adjust the mast to have the track point as straight aft as my eye can get it before actually locking in the forestay. Things really don't move after that.
DigitalMechanic
 
Posts: 374
Joined: Sat Nov 07, 2015 7:00 am
Location: Jacksonville, FL


Return to Rigging

Who is online

Users browsing this forum: No registered users and 27 guests