Spreader (lower) rivet replacement - size & suggestions

[svaurore]

My first post, hope this is the right topic category.

I'm a new owner of a Sun-Rise 35 (last year of production, 1989, commissioned 1991). Here's a pic of a loose rivet in the spreader arm:



I'd like to learn the size and depth (specification) of the rivet, so I can replace it. Could anyone point me to this information? My plan is to loosen the rig and remove the spreader. Since I live in Japan, items like rivets of this size and a heavy-duty gun may be things I need to order in advance of removal. Any advice is greatly appreciated,

Richard

[rene460]

Hi svaurore,

Welcome to the forum.  You are on the right track, noticing and attending to that rivet.  I don't know the size or length of the rivet and you may need to try and measure the diameter, and remove it to measure the length, not much help if you have to order it in I know, but the length has to provide the right grip range and the diameter should be a firm fit in the hole.  Due to the corrosion, you may be better to enlarge the hole for the next size larger to get a good fit.  If you do not get other replies, try contacting the mast manufacturer who may be able to advise you if you tell them the mast serial number or at least make and year of the boat, as it looks like a special fitting.

Additional preparation to consider, order some corrosion resisting grease to slow down future corrosion, the Aluminium spreader corrodes to protect the Stainless steel rivet, as you would use for any other mast or boom fittings.  Cleaning the corrosion product and some special paint for Aluminium will also help.

It is a really nice fitting and removing the split pin and pivot shaft will allow you to bring the spreader to the deck for cleaning up and rivet replacement.  (Order a replacement split pin as it has been opened wide.). Also loosen the shrouds on both sides, and mark the location of the outer end of the spreader on the shroud so you can replace it at the same location.  The spreader should bisect the angle between the upper and lower shrouds and be fixed from sliding up or down.  Check the other side while you are at it.  If you only loosen one side, the mast will be pushed out of line by the other side, and it is easier to keep it straight than tune it back to straight later.

I hope this helps, if it is not clear please ask, 

rene460

[svaurore]

Hello rene460,

Thanks very much for your excellent suggestions, and welcome.

One question, after I remove the split pin, is it possible to use a punch and mallet to push the pivot shaft out of its bearings, or would this cause damage? It's difficult for me to tell how the hinge system is put together (my first experience with this).

I'd add that when sailing, I believe this spreader was riding up (and down) to some extent on the shrouds -- what might be a good way to fix the spreader from sliding up or down?

Thanks again,
Richard

[rene460]

Hi Richard,

Glad to be of assistance.

For removing the pin, a hammer and punch will probably be essential, it is important to capture the pin before you start, perhaps with that useful duct tape wrapped right around the spreader, as if it suddenly releases it will be extremely dangerous to anyone on deck and in any case will almost certainly bounce into the water never to be seen again.  The pin looks like stainless steel in an aluminium casting, a notorious combination for corrosion, like gooseneck pins and the shafts of other boom pulleys.  Use protective grease on reassembly.

However a hammer and punch is brutal, especially when you are up the mast, and a safer process is to mock up something like a wheel puller with threaded rods, nuts and two bars with holes drilled in the appropriate places.  If this description does not convey a suitable picture, send me a PM with your email address and I will send you a sketch.

It is not a good idea to sail with the spreader ends sliding up and down, they can reach a point where the shroud suddenly goes slack, probably in strong wind or wave conditions.  On small boats they are often bound with stainless steel wire, but this is a bit inadequate for our larger boats.  Again I would try contacting the mast manufacturer to see if they have special fittings.  It depends a bit on whether you have a single shroud from mast head to chain plates, or an additional diagonal from the mast at the upper spreaders to the end of the lower spreader as they must all be fixed together at the end of the spreader.  If you have a good rigger they may be able to help, or quite likely someone else will join the conversation with more precise suggestions.  I am not sure whether a simple clamp above and below the spreader end causes any corrosion problems in the wire strands.

The main point is that they must be fixed to the shroud, angled up so the spreader bisects the angle between the upper and lower part of the shroud as the force causing the sliding is least at that point.  Then, depending on the actual arrangement you may need to pad the end with soft leather to protect the sails when running.

rene460

[svaurore]

Thank you again Rene,

I just PM'd you..

[so36idavid]

Oct 6, 2015 2:48:52 GMT svaurore said:

I'd add that when sailing, I believe this spreader was riding up (and down) to some extent on the shrouds -- what might be a good way to fix the spreader from sliding up or down?

I second the suggestion to contact the rig manufacturer on this, they should not be sliding. The next step would be to go up the rig, take the spreader boots off and see what's going on there. Inspection will probably tell you what you need to do.

A technique that I've used in the past is to put a few tight turns of monel seizing wire around the shroud both above and below the spreader and through a pair of holes drilled close to the ends of the spreaders. Generally these holes will already be there. You may also want to put some rigging or other tape around the shroud where it meets the spreaders, just to stop them corroding and/or chewing into each other. 

If you're up there and unsure, take a picture and post it here, I'm sure someone will have a good idea.

David

[svaurore]

Thanks, here's pics of starboard lower spreader tip (and a shot of the standing rigging) -- there's a "C" hook, fixed with a screw -- I suspect this hook may have become too loose, if it was supposed to be sung to begin with (a single screw doesn't seem like it would be sufficient to keep tension on this clamp?):

Lower-right spreader tip (top)


Lower-right spreader tip (bottom)


View of mast & standing rigging

[rxc]

One bit of experience on using a punch to get that pin out. I had to do that to remove my spreaders, each of which has two pins that go thru a central aluminum casting that spans my entire mast (43DS with RF). The pins were corroded in place and after I soaked them in PBlaster I tried to tap them out with a punch. Turned out that the punch made it even more difficult because I used a much smaller punch than the pin. I effectively mushroomed the tip of the pin and turned it into a rivet. With subsequent pins I used a bigger punch and once they were loostened I grabbed the tend with a vice-grips and twisted them out. They will have to be replaced, but it seems that they are much softer than I had imagined. They will deform if you hit them hard enough and then they are really difficult to get out.

Also, if a pin is loose, you WILL launch it when you hit it, so install some way of catching it (one pin of mine is irretrievably lost in high grass).

Oh, and I don't envy you doing this on the mast. Would STRONGLY advise taking down the rig first and doing it on land. How are you going to keep the mast straight when you loosten the stay and then hoist yourself up there and remove the spreader?

[so36idavid]

Oct 7, 2015 7:46:22 GMT svaurore said:

Thanks, here's pics of starboard lower spreader tip (and a shot of the standing rigging) -- there's a "C" hook, fixed with a screw -- I suspect this hook may have become too loose, if it was supposed to be sung to begin with (a single screw doesn't seem like it would be sufficient to keep tension on this clamp?):

It's quite hard to see what's going on under that spreader boot. You might have to take it off to figure this out. I assume that the screw head that's visible on the upper side is the one that snugs the  "C hook" (whatever that is)? It appears that some kind of fitting slides into the end of the spreader and is then secured by the screw? If that's the case then it shouldn't have loosened unless the hole has been elongated. If that's the case then the solution would be to drill it out and use a bigger screw. Or possibly through-bolt it. 

Without knowledge of your specific mast I would advise talking to the manufacturer or a rigger who knows what he's looking at. Sorry...

David

[rene460]

Hi Richard,

It is amazing how quickly little jobs like replacing a loose rivet can get out of hand.  After focussing on the details of the job it is necessary, as rxc has pointed, out to stand back and look at the whole job before beginning.  

I had assumed that so long as you loosen off the port side upper shrouds before you start, the lower stays would be enough to get you up to the lower spreaders, but I agree with the point that you need to be very sure of this before proceeding, and defer to his greater experience in this area.  Other forum members may also be able to advise on what they do.

It will not change the details of the job, but it is worth reviewing what facilities are available to you at or near the current marina, and the one you are moving to, for removing the mast, before you start, especially if you are not sure of the age of the rigging.  It may not be too expensive if they have a crane available where you slip the boat for antifouling.  Can you ask other owners what they do?

David has also made some good observations on the spreader tips.  It is a great strength of this forum that so many members have such expertise to contribute, and do contribute.

I am glad the sketch was helpful

rene460

[svaurore]

I have the spreader hinge-pin 'pusher' built now. The sketch was more than helpful!

Tomorrow I'll be at the boat scoping things out. First, at the spreader tip, to see if I can detach the eyelet hook assembly from the shrouds.

Everyone's advice is very much appreciated, especially on monel wire and boots, both of which can be added, given I can fix the spreader itself. Plenty to consider, as well.

I live in a small city on an island with few yachts. Possibly a mast can be pulled in two places I know of, both involve over a day of motoring the boat, half a day by car, daily yard fees, and questionable expertise. This is not to mention overall expense. If I were going to do a complete overhaul of all the spreaders and the electrics, such a job would make sense. But I just want to remove one lower spreader first. to put this in perspective, the proper stainless steel rivets may not be available in-country. To move the boat, pull the mast and then find this out?

Please tell me how foolish this is:
1) I remove the lower-starboard spreader.

2) I fashion a spreader blank out of hardwood (done in a couple of hours).

3) I mount the blank, while fixing the removed spreader, over 7-10 days (max). I snug the upper shrouds with tension against the spreader blank.

4) Weather: Over the next 2 weeks, max winds 7 knots, usually 0-4, no waves in the protected fishing harbor. The boat is fendered against a pier along its portside length, with spring lines and a double set of bow and stern docking lines.

Is there concern that the 4 inner shrouds (2 per side) to the lower spreader are insufficient for mast support, if I ascend on a mainsheet halyard (with spinnaker halyard as a safety line)? I'm not going up beyond the lower spreader.

Penny for your thoughts,
Richard

[so36idavid]

If you're using halyards to ascend then you need lateral support at the masthead, particularly as you swing outboard towards the spreader tips. I would not be confident in going up with slack upper shrouds. Maybe use spin halyards fastened to the toe rail or midships cleats?

[svaurore]

Thanks, will do.

[rene460]

Hi Richard, 

I strongly agree with the suggestion to use a halliard to the toe rail or suitable mid ship cleat to give side support to the top of the mast.  A halliard tied off on the base of the mast does nothing for you, so I would use all that you have, as it is hard to be sure how much tension you get in each.  Assuming you have main, jib and spinnaker halliards, and possibly a boom topping lift, you should be able to use one to lift yourself, a second as a safety line and still have two for the mast.   If you have a spinnaker pole topping lift it may also exit the mast high enough to be useful.  All tied off to different deck fittings.

It is also worth considering if you can make your wooden spreader so it fits just above the normal spreader and take a little shroud tension off the aluminium spreaders as this will retain some top mast support and also ease the compression load on the spreader and make the pin easier to remove.  It may need some fore and aft support so it stays in place while needed.  Just a thought, if you can think of a way to do it.

rene460

[svaurore]

Grateful for all the advice and suggestions!

I was successful today in removing the spreader (lateral support from halyards was provided, when the shrouds were slackened).

The spreader tip was tricky, at first, after removing a rather small set-screw on the top, I could barely move it up/down on the (still tensioned) shrouds, and could not see a way to pry off the cover. Since I could move it, I decided to go to the next step and loosen the shrouds and try again. With the shrouds loosened, I was able to pull out the entire cap assembly, with the hook still firmly attached around the shrouds. The end pops out, and the hook is held by something about the size of a 7-8mm nut and washer, in back (I used a pliers to loosen it, it wasn't all that tight).

The spreader mast hinge became actually a bit loose in its socket after shroud de-tensioning. That was a surprise. I was able to tap the pin out, without a lot of force, and a bit of twisting.

So I discovered some strange facts. The hinge pins on the port and starboard lower spreaders differ. The port side (which remains tight) uses a hollow pin with an open slot along its length -- so it's a compression pin, which compressed as it was pushed in. This pin (and the hinge-plate holes it sets in) eyeball as smaller in diameter than the starboard side -- which uses a solid stainless steel pin. So this is weird. I can see no machining on either of the hinge plates -- no outward sign of modifications.

So the main problem with the spreader is (was) twofold:
1) The hinge was or became or was originally (if a retrofit) a bit too small for the hinge plate and this created horizontal play in the spreader.

2) The broken rivet created play between the spreader body and its own hinge fitting (tang).

3) It's unlikely the spreader tip was moving much, vertically, unless the shrouds were also moving oddly under sail, in (feedback) response to the loose spreader.

At this point, I'm not exactly sure how to replace the stainless steel spreader pin, as I can't imagine adding diameter thickness to it.

The pin measures 10mm dia. x 87mm length.

 (The pin is also loose in the spreader tang -- it just seems the wrong size). If I could find a compression pin the right size (as on the port side spreader) that might be one solution. (It shouldn't be difficult to replace the rivets in the spreader -- and go up one size, if I can source stainless rivets -- they aren't that big.)

My mast is ZSPARS -- there is no visible model/serial number for the mast, that we could see.

That's about all for now -- we have a 3-day weekend here, and I'll do some consulting later this week and see what can be fixed or replaced.

It was a challenge! Having the spreader and its parts in hand makes things a whole lot easier.

[so36idavid]

I would guess that at some point the compression pin worked itself loose or maybe enlarged the hole a little and then a previous owner put in his fix. 

McMaster-Carr has a wide assortment of stainless compression pins (they call them "spring pins"), if you were in the US you could order one exactly to size for about $3. I'm sure that there are industrial supply places in Japan, but if you can't find it you could probably order them from the US and eat the price of shipping. If that doesn't work I'd be happy to source them and send you a couple of them.

Why not just drill out the hole, put a big stainless bolt through the whole contraption and go sailing?

David

[svaurore]

Thanks David,

Glad to have your suggestions and thanks for your offer of help. I am right now looking online for "spring pin" (aka "slotted spring pin") availability in Japan. For sure, a non-threaded stainless bolt (with threads only at the tip) is possible, but a spring pin seems best. I was hunting around, wondering what those things were called. (It's the same in Japanese, in katakana -- looks like they exist here.)

[rene460]

Hi Richard, 

Looks like great progress so far.  Those hollow cylindrical pins with the longitudinal split are sometimes called roll pins.  Might help with looking for the appropriate translation.

Is there a chance that in the past there has been confusion between 3/8 inch (9.525 mm) and 10 mm sizes.  You almost need callipers to pick the difference, but a 3/8 in pin will be a very sloppy fit in a 10 mm hole.  One inch is 25.4 mm exactly for any other conversions you need.

The 7-8mm nut is more likely 8 mm, as 7 mm is a unusual (but not impossible for a specially made component) size, but again, if any imperial sizes have crept in, 5/16 is 7.94 mm but the thread pitch would be different.  Good news that the hook restrains the spreader tip.  Is it possible that the hook is initially adjusted by the nut lie component, then pulled up tight by insertion of the screw.

rene460

[svaurore]

Yes, I've been looking at the metric conversions and sizes, always good to be aware. Today, I removed one rivet, the loose one, which was broken off, and then after locating local stainless rivets that seemed to fit, I cleaned off and drilled out the remaining rivet -- it appears to be bronze. Can't have been original. With the rivets out I could pull out the tang. The tang wasn't properly drilled out for the second rivet, which was why it failed. There was some aluminum corrosion as well, around the holes (not a lot). I drilled out to 5mm, only slightly larger, and drilled through the connecting side of the tang.

I wasn't able to source Tef-Gel, or the Locktite product, but did find Bostik '"Never-Seez" 'Mariner's Choice', which I'll use on the fittings (rivets, nuts and bolts).

The hinge pin I took out was exactly 10mm in diameter. A French builder with its life in Japan -- would Zspars use non-metric fittings on the mast? You'd have to work hard to retrofit non-metric fittings here, on a sailboat mast. If I wasn't able to find a M10 spring pin (which is un-compressed at 10.6mm, and has compression at 10.3mm -- hoping this is enough to take up the slop, as the next size up is 12M), I was thinking about a spring pin at 7/16" (or even 1/2") -- probably sourced from the States.

So the spreader tip assembly is really simple (still haven't put a wrench on that nut which as you say is likely 8mm). First it's mounted to the shrouds, locked down tight with nut and lock washer, then it snaps into the spreader tip, finally it's secured by just one modest screw into its plastic base, through the top of the spreader - as you thought. There is plenty of positive shroud tension keeping that assembly in place.

I surmise that originally the hinge plate had a proper spring pin? And someone retrofitted a solid pin that never really fit right -- along with bronze rivets. I'll never know. I'm concerned the holes have widened too much for an M10 spring pin -- it will be tighter than before, and the spreader will be securely locked down to it's tang. Famous last words.

If lucky, I'll have the spreader back on the mast this Sunday (more famous last words).

I'll take some photos soon and link them in case anyone wonders what this all looks like, just been too busy. I cut the old incandescent (or halogen) light assembly off the spreader, and plan to do this to the port side as well, and replace with LED assemblies, by and by.

Oh, one more reply -- I found "roll pins" both at the local home center and online -- none I could find in Japan were large or long enough --- also they seemed to be made (here) of budget-level iron.

[rene460]

Hi Richard,

If the 10 mm pin is loose in the whole it does not look like a metric/imperial mixup.  Is it possible that the hole has worn?   Quite a mystery!

 Quite a mystery, but the more important issue is how to proceed.  The bolt solution and go sailing starts to sound quite rational.

At least the spreader tip is sounding good, and the 5 mm rivet will fix the original issue.

rene460

[svaurore]

I ordered 10mm and 12mm spring pins, and will check them for fit against the hinge tang on the spreader. The solid hinge pin that came out is about as loose on the tang as it is through the mast hinge.

If neither of the spring pins will work, I'll try and work out a sleeve-and-bolt arrangement, a nice workable idea (thanks for it).

[svaurore]

Some photos (waiting for the spring pin to be delivered),

Spreader hinge assembly:


Close-up of rivets positioned:


Spreader tip assembly. The nut takes a 10mm socket: