Author Topic: Spreader Replacement  (Read 474 times)

jankowskiben

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Spreader Replacement
« on: March 21, 2021, 09:49:08 PM »
Spreaders on my main mast are warn at the mast rattle fore and aft more than they should.  The pin holes in the aluminum spreader are egged out, and both the spreader mount and but base show wear.   Side effect of a mast stepped year-round for decades.  Mizzen mast spreaders remain like new. 

Looking to replace main mast spreaders and mast mounts.   Has anyone done this replacement?  Suggestions, advice appreciated. 

Thanks!

Dale Tanski

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Re: Spreader Replacement
« Reply #1 on: March 22, 2021, 10:41:52 AM »
Finding exact replacements will be very difficult to obtain.  We have taken old and "loose" spreaders and their mounts and TIG weld them to replace the missing material. We then remachine the parts to all fit the way it used to. 

If you could send us a few pictures of both ends I could ge a better feel for the amount of wear we are talking about.

Dale

Obersheimer

(716) 877-8221

"Maruska"
Pearson 365 Cutter Ketch
1976 Hull #40
Buffalo, N.Y.

jankowskiben

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Re: Spreader Replacement
« Reply #2 on: March 23, 2021, 10:40:15 PM »
Thank you for a thoughtful reply, Dale.  Existing spreader bases are in good shape, spreaders themselves are warn.  Egged out pin holes and bell shaped where ends meet the mast mounts.  Would love to find someone who can tac weld to replace wear. 

Dale Tanski

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Re: Spreader Replacement
« Reply #3 on: March 24, 2021, 07:46:28 AM »
It would appear that the boat spent lots of time with a rig that was tensioned way too little, allowing the spreaders to bounce back and forth with each wave.  When the uppers are tensioned properly, the spreaders are held in place by the compressive loads on the spreader and typically never move about. 

Yes, your holes are worn, very worn.  The tell tail flaring of the trailing edge against the mast (bell shaped) is huge give a way of the rocking back and forth.  My guess is someone along the way in owners had a wooden boat and was used to slack shrouds, and carried that train of thought over to a boat that doesn’t pull itself out of shape (hog) with heavier rig tension. 

The holes can indeed be welded in and re-drilled to establish the correct inner diameter.  I just had another thought however… How handy are you? My guess is because you even recognized this issue, your mechanical skill sets are a bit above most.  You could fix this yourself without welding.  You could drill out the holes and insert flanged bushings into the new oversized holes that would give you the correct inner diameter.  Go to McMaster Carr and search for "Sleeve Bearings".  Then click on the picture of "Flanged Bearings " in the left hand margin under “Bearing Type”. Scroll down and select "Corrosion-Resistant Flanged Sleeve Bearings" in the lowest "Flanges Sleeve Bearings" category.  Here you will find 954 Aluminum-Bronze Bearings.  Select the correct "shaft diameter" which is you pin diameter, and then select the next "Housing ID" which would be the size of the hole you re-drill your existing holes.  The flange will keep the bearing in place and all you will have to do is file or sand on a belt sander the bearing portion until it becomes the correct depth and allows the spreader base to slide into the spreader.  Aluminum-Bronze is nice and hard but will not be so hard that you cannot "remove" some of it easily. 

My spreaders are laying at my shop so if you need me to recommend a sleeve, just let me know.  If this is outside of your wheel house we can do it for you.  Welding is the most permanent solution I suppose, but it will take far longer, cost more and ruin the anodize on the spreader itself.  This might be the excuse you need to paint them anyway.  One advantage to the bearing insert is that 40 years from now the next owner can pop them out and replace them with a fresh set. 

One other thing…  Traditionally spreader pins are standard clevis pins with a head on one end which is what you have.  Sometimes they even used riggers pins which have holes and rings on either end with no head.  There is no reason that you cannot use a stainless bolt and NYLOK nut in place of the pins.  You should/must use a bolt that is not threaded all the way to the head as the threads act like a file if there is any movement.  Select a bolt that has a smooth shank as long as you can get it just so there are threads sticking out. Cut the remainder of the threaded section out just above the NYLOK nut.  We typically install the nut on the bolt and then cut off the remainder of the threaded section of the bolt.  A bolt method has several advantages.  One is that you can apply some tension and slightly tighten (not crush) that connection and increase the resistance to movement of the spreader to spreader base connection.  The snugged up bolt also does not move around creating additional wear as time goes on and there are no rings to get snagged and accidentially removed or cotters to get out. 

Hope this all helps.
Good Sailing

Dale @ Obersheimers
"Maruska"
Pearson 365 Cutter Ketch
1976 Hull #40
Buffalo, N.Y.

jankowskiben

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Re: Spreader Replacement
« Reply #4 on: March 24, 2021, 09:07:03 AM »
Very helpful, Dale!!  Thank you.  My boat spent decades sitting with the rig up year round, and poorly tuned, in Wisconsin.  I actually thought about over-drilling and using a bushing, but didn't know where to start looking for a vendor.  Like the idea of avoiding heat from welding.   

I'll take some measurements next time I'm at the boat yard.  That said, if you have a chance to take measurements I would greatly appreciate it.  I'm fairly handy, but don't do this sort of the every day.  Extra eyesight is invaluable. 

Thanks, again!
Ben

jankowskiben

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Re: Spreader Replacement
« Reply #5 on: March 29, 2021, 09:42:37 PM »
Bushings in place.  Turns out my clevis pins are tapered slightly toward the head.  Will be replacing and/or swapping with bolts.  Thank you, again, Dale!!! 

Dale Tanski

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Re: Spreader Replacement
« Reply #6 on: March 30, 2021, 08:05:11 AM »
That's the ticket!
Dale
"Maruska"
Pearson 365 Cutter Ketch
1976 Hull #40
Buffalo, N.Y.

SV Alfresco

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Re: Spreader Replacement
« Reply #7 on: April 01, 2021, 09:14:23 AM »
On my spreaders, one of the hooks where shroud goes was broken off by the yard. Drilled a hole and use wire to keep the shroud in place. Is there a better solution?

Dale Tanski

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Re: Spreader Replacement
« Reply #8 on: April 01, 2021, 10:07:08 AM »
Using a seizing wire to hold shrouds in place at the end of a spreader is a common method in smaller boats.  Another method we like is when the rig builder uses a small plate held in place with screws at the end of the spreader.  The plate captures and holds the shrouds that ride in the slot at the end of the spreader.  I’ll have to look at my spreaders, but I believe that you can flatten the spreader end slightly for a spot to drill and tap the screw holes to hold the plate.  Any 2 hole plate such as a backer plate will work. 

Let me look at my spreaders and I will get back to you.

Dale
"Maruska"
Pearson 365 Cutter Ketch
1976 Hull #40
Buffalo, N.Y.

jankowskiben

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Re: Spreader Replacement
« Reply #9 on: April 04, 2021, 09:46:04 PM »
Fitted the spreaders w/ bushings at the mast today.  Tight up and up/down - spreaders now rest at an angle the bisects the shroud!

Trouble is fore/aft play.  Belling is so severe that the spreader tips are free to move a few inches fore/aft at the tips.  Unsure if this will be an issue when rig is upright and tensioned? 

Wondering about adding metal to the belled area on the inside of spreaders with low temp aluminum brazing rod:  https://www.amazon.com/Blue-Demon-BDTP-125-01T-Aluminum-Zinc-Brazing/dp/B01MCTUIUN   

Thought is to build up metal on the inside and grind to fit with a dremel tool.  That said, I don't know enough about metals to evaluate corrosion implications of aluminum/zinc brazing.  My boat is in salt water.


Should I be considered about fore/aft spreader play?  Thanks!!