removal of anchor locker

[mjsouleman]

Mark, did you have any issues with your bow chain plate or were you just being careful and proactive?
Frank

Frank,
I have owned this 1983 sailboat for 9 years and I have no idea if or when the chain plates had been replaced. For my own peace of mind and while I was removing rub rails and fixing deck to hull leaks I figured what the heck why not.

Removing the bow chain plate was not bad, My brother helped and was paid lunch and gas money to turn the screwdriver while I put a wrench on the nut. 1.5 hours of work, scraped knuckles and achy back and the chain plates were off.

 

[Prairie Schooner]

Frank,
I have owned this 1983 sailboat for 9 years and I have no idea if or when the chain plates had been replaced. For my own peace of mind and while I was removing rub rails and fixing deck to hull leaks I figured what the heck why not.

Removing the bow chain plate was not bad, My brother helped and was paid lunch and gas money to turn the screwdriver while I put a wrench on the nut. 1.5 hours of work, scraped knuckles and achy back and the chain plates were off.

Mark,
How did you find a metallurgist to do this inspection?
Jeff

 

[Loren Beach]

Different SS plates will exhibit different "aging. When we removed all of the plates on our boat for the re-fit, I was really curious to see if we'd find any microscopic (or maybe not so micro....) cracks. Our complicated welded bow fitting (same as most 80's E boats) was fine. I buffed it up to a mirror polish before reinstalling.
Our big SS back stay tang was also in perfect condition, and was also polished up. Ditto the shroud base fittings. However, a sister ship had to replace the BS tang, a year prior, due to small cracks around several bolt holes. I saw the part and it was indeed worrisome once removed and cleaned up.
Our ship wright told us that this is not unusual. A lot of boats over 30 years old (to use round numbers) will have SS that is either corroded where you cannot see - behind or under - and also will develop cracking.

Everything depends on the alloy and the fabrication and installation procedures done all those decades ago. And, how well sealed it has been to keep water out from around the back or any parts under a deck.

We inspected all of the bolts for the bow and stern plates, too. Buffed the heads to a mirror finish. Satisfying Work!

 

[Christian Williams]

I concluded that the cracks in my backstay chainplate were the result of Ericson practice of "screwing" bolts into the glass transom, essentially tapping them with no allowance for movement. That prevented the chainplate from self-aligning, as it would have been able to if the holes allowed any play. You could observe the slight misalignment by eye.

When I installed the new chainplate into appropriate holes, it self-aligned immediately.

I think the backstay fitting in particular must be sometimes overlooked in inspections because on the hard it's an awkward ladder placement and in the water it takes a dinghy.

......

 

[bigd14]

You could observe the slight misalignment by eye.

A bit of thread drift here but this got me thinking about the forestay chainplate on my 30+ which is ever so slightly misaligned to the forestay (the mast is centered!).

I had a new chainplate made using the old one as a template and it was an exact match so I believe that the original forestay was installed slightly angled. Furthermore, the single long wood screw that holds the upper part of the chainstay to the "fo'c'sle" regularly works loose since the wood core is likely rotted in there. The chainplate visibly twists when the sail is full and the forestay bends to one side or the other. The anchor roller likely supports the chainplate a bit on the starboard side. I know some models have the chainplate welded to the anchor roller to prevent this twisting. I suspect this twist is undesirable but I am not sure how much of a problem it might be or how much it might shorten the chainplate lifespan. For now I will be repairing the fo'c'sle this spring and using a through-bolt to replace the woodscrew. And I will likely plan on replacing the forestay chainplate in another 5-10 years (freshwater boat for now) to proactively avoid any issues. Pics below.

Removing the bow chain plate was not bad, My brother helped and was paid lunch and gas money to turn the screwdriver while I put a wrench on the nut.

I was able to get some of the lower bolts off single handedly using a vise grips on the nut, but the ones way up in the bow needed an assistant. There is a funky little tie-down bracket that attaches to a chainplate bolt and one of the bolts from the anchor roller/tack fitting unit to help disperse the forestay tension loads (or more likely the halyard tension loads for hank on sails).

 

[Kenneth K]

A bit of thread drift here but this got me thinking about the forestay chainplate on my 30+ which is ever so slightly misaligned to the forestay (the mast is centered!).

A bit of a side point, but do you know if that lower turnbuckle bolt is a threaded all the way through, or does it have a solid section in the middle with two threaded ends?

I think a rigger would prefer the latter, which any machine shop could quickly fabricate from a normal bolt.

What is the deck fill for?

 

[bigd14]

A bit of a side point, but do you know if that lower turnbuckle bolt is a threaded all the way through, or does it have a solid section in the middle with two threaded ends?
View attachment 46219

I think a rigger would prefer the latter, which any machine shop could quickly fabricate from a normal bolt.

What is the deck fill for?

Hey Ken, good eye and catch. That is a Profurl clevis pin with threads only on the ends provided by Rigging Only when they duplicated all my rigging, so it's all up to spec! The original was just a bolt I think. They were very helpful in providing everything I needed with lots of emails and phone calls back and forth. Love those guys...

The deck fill was for an optional forward water tank that was never installed. There was a hose running from the fill to the space under the V berth, which was removed during the anchor locker modification. When I replace the cracked and rotten fo'c'sle structure I may have to remove the deck fill to create enough space to bond the new materials in place. I may also be able to get away with simply making a new structure out of G10 and bonding it directly to the deck with thickened epoxy rather than with a lot of fiberglass tape. The 7 big through-bolts holding the stem casting down should stabilize the entire structure. And now I am just realizing that trying to convert the topmost chainplate screw into a through-bolt wont work because the three stem casting bolts are in the way. Ugh...

 

[mjsouleman]

Hey Ken, good eye and catch. That is a Profurl clevis pin with threads only on the ends provided by Rigging Only when they duplicated all my rigging, so it's all up to spec! The original was just a bolt I think. They were very helpful in providing everything I needed with lots of emails and phone calls back and forth. Love those guys...

The deck fill was for an optional forward water tank that was never installed. There was a hose running from the fill to the space under the V berth, which was removed during the anchor locker modification. When I replace the cracked and rotten fo'c'sle structure I may have to remove the deck fill to create enough space to bond the new materials in place. I may also be able to get away with simply making a new structure out of G10 and bonding it directly to the deck with thickened epoxy rather than with a lot of fiberglass tape. The 7 big through-bolts holding the stem casting down should stabilize the entire structure. And now I am just realizing that trying to convert the topmost chainplate screw into a through-bolt wont work because the three stem casting bolts are in the way. Ugh...

View attachment 46220

"deck fill was for an optional forward water tank "
On my 1983 E-30+ the forward water tank and fill tube are still in place but I have a paper design to use repurpose that water tank as a fresh water source for the head.

 

[mjsouleman]

Mark,
How did you find a metallurgist to do this inspection?
Jeff

Started with a shop on Fish St in Tiverton that does all the SS work for Safe Harbor Sakonnet. From there I stopped by Seven Star Marine engineering in New Port.

 

[mjsouleman]

Mark, did you have any issues with your bow chain plate or were you just being careful and proactive?
Frank

Frank,
Just being careful as this is a 40 year old sailboat and there was no history of maintenance.

 

[Kenneth K]

And now I am just realizing that trying to convert the topmost chainplate screw into a through-bolt wont work because the three stem casting bolts are in the way. Ugh...

Well, if you build the new "fo'c'sle" out of G10, you might be able to drill a hole from the top (or side) to hold a barrel nut that catches the chainplate screw (bolt). Even cooler if you could tap threads into the G10 as well, but the threads would have to match up with the barrel nut threads, which might be tough.



If there is not enough space for a barrel nut in front of that forward center casting thru-bolt bolt, perhaps you could just just omit the forward casting bolt--I don't see how there'd ever be enough upward force on the anchor roller assembly to require all seven bolts. Or, have someone make a custom, oversized (say 3/4" dia) dual-axis barrel nut that can capture both the chainplate bolt and the casting bolt.

 

[bigd14]

Dual-axis barrel nut, wow that's next level!

I feel like the tapped G10 might eventually work free/damage the threads given the constant movement of the chainstay. I think a standard barrel nut and omitting the forward bolt may be the ticket. That way everything is replaceable as needed. Excellent ideas, thank you.

 

[Loren Beach]

If looking for a way to drive threaded bolts into the flange of the deck to secure the edge of the "anchor tub" you might want to consider threading bolts into G10. Note that you do want to consider the holding power of the frp plate, but my intuition is that this might be done using a quarter-20 bolt, or more likely a #12. An inch wide piece of G10, about 3/8" thick should hold the threads very very well. It could be epoxied into place underneath and then the fastenings just drilled and threaded into it from the top the normal way.
This would allow disassembly later, albeit with still having to break loose the sealant bond.

This was the method our ship wright used to replace all of the fastenings for both our vent hatch (Lewmar #20) and our fore hatch (Lewmar #70). The bolts withstood extreme torque when installing, with no stripping out of threads at all, I should note.
Strength should not be a concern, as the tub is not subject to any lifting forces and is not 'structural' to the front surface of the foredeck.