Repairing forestay tang in Anderson 22.

[Samoddie]

It turns out that the 40 plus year old boat I bought has a forestay tang that is fixed to a fibreglass structure inside the anchor locker (access is not joyful). The fibreglass seems to have been formed round a piece of wood. The stainless plate that the forestay is secured to is bolted to that (by a bolt that was rusty, but secure til I ground I out). The fibreglass itself is presumably OK, but the wood it was (I think) formed round, is powdered. Forestay tang allowed water to seep into the compartment, from which there was no escape. My plan, at present is to try to build a resin replacement for the wood from the inside, while destroying as little as possible of the current structure (a fore aft orientated vertical plane seen in pic at end of the 25mm blue water pipe section. I thought then to add to the fibreglass layers, and then bolt forestay tang back in place with 10mm A4 SS bolt. What thoughts have people who actually know about boat building?

 

[anoccasionalyachtsman]

I can't see your picture, which may be because you're restricted as a new user. If you email it to ybwemail @ gmail.com I'll post it for you.

If it shows what I think you described then your plan is good, but do use epoxy and eglass for a proper bond to the freshly abraded old laminate.

 

[oldbloke]

The way you have written it, it sounds as if there is only one bolt holding the tang. It may be a typo, but I would want the attachment to the boat to be much more spread out and would also be happier with a through bolt and a plate on the outside

 

[AntarcticPilot]

I thought that Anderson 22s were made of pure unobtainium and could expect to outlast the heat death of the Universe? No to mention being able to approach light-speed if handled correctly.
For those who don't get it, there is a rather over-enthusiastic proponent of the Anderson 22 on these fora!

 

[alahol2]

I feel for you, I had exactly the same problem (different class of boat). Unfortunately even a slim Hobbit would have had difficulty doing any sort of GRP layup. I even considered removing a chunk of foredeck to gain access. If you can get in there and do the work then your plan sounds like a good one.
Bear in mind that the internal bulkhead will be offset slightly so that the tang of the forestay fitting is on the centreline.
I managed to solve the problem by fitting a substantial, horizontal stainless plate that transferred the load to the hull sides. That was only possible because of the design of the hull/deck join.

 

[anoccasionalyachtsman]

The way you have written it, it sounds as if there is only one bolt holding the tang. It may be a typo, but I would want the attachment to the boat to be much more spread out and would also be happier with a through bolt and a plate on the outside

I think this one's in shear through the web, so as long as it's as big as the single clevis pins holding the forestay on then one is absolutely fine.

 

[lustyd]

there is a rather over-enthusiastic proponent of the Anderson 22 on these fora!

I thought he left after relentless ribbing about the A22?

 

[AntarcticPilot]

I thought he left after relentless ribbing about the A22?

Not sure, but I think he's still around under a new ID. But he was quite good-natured about being ribbed - I think it was something else.

 

[lustyd]

Ah good to hear it, he was certainly a great contributor

 

[Greenheart]

Hello Samoddie. I'll tell you all I know...from your description, I had broadly the same problem, although in an Achilles 24...

...but I really think it's similar or identical to solve.

I was appalled when I looked in the front of my anchor locker, which was torture to reach into. The original (mild steel) 'tang' had been fitted by the builder to transfer the forces from the rig, through the fairly thin GRP deck, to the much sturdier bow.

After 40 years, the tang was just a rusty stain on the locker-wall, and the only thing spreading the rig-loads applied to the deck bolt, was a piece of 20mm plywood the size of a pack of cards, under the deck. It had been bent and flattened by the upward forces...

...really not good, and I wondered how many other Achilles 24-owners drive their boats hard upwind, not knowing or daring to think about when or whether it may let go, and topple the mast.

Anyway, you want to know how to solve it. My solution was not subtle, but it was very strong.

Firstly, given how admirably that little piece of plywood had spread the burden of the rig-loads for so long, I was determined to replace it, in case my main solution ever failed, as the builder's own original tang, had. I used a 20mm-thick slab of acetal (nylon) which is extremely robust, but can be planed to fit, and I needed to shape it because the deckhead wasn't totally flat.

Then I drilled two 8mm holes, 40mm vertically apart, straight through the (reassuringly thick) stem of the boat, at a point which emerged inside the anchor locker - so the line taken by the forestay now continued straight through the foredeck, and ended at the much sturdier solid GRP bow, low down...and I bolted an 8mm-thick U-bolt through the drilled holes, bend inwards...

I also needed to make the U-bolt to which the forestay is attached on deck, extend below deck in the same way, so I bought an 'eye-plate' like the one below, which fitted onto the threaded ends of the U-bolt sticking through the acetal plate below the deck...

All I needed then, was to strongly connect the two steel eyes, one low in the stem, the other on the 'ceiling' of the anchor locker...

...so I bought the right size of bottle-screw, and I'm still amazed at how effective the result was. It deserves a better photo...

I nearly bought an Anderson 22 a few years back, with the help of the gent who's been mentioned here. At the time, I knew nothing about 'tangs', nor the inadequate metal which Anderson and Achilles builders had used for such an important component in a marine environment...in my ignorance, I was nervous when told it might need doing. But seriously, if I could achieve this solution, anybody could; and it wasn't even very costly.

Meanwhile, if you're worried, it's worth reflecting that we don't hear often about yacht rigs falling down.

EDIT...Reading the opening post again, I don't think Samoddie needed to follow my advice as much as I needed to give it!

 

[Keith 66]

I had exactly this problem on an Anderson 22 that i virtually rebuilt some years back. Access to repair is very tight. I solved this by the simple expedient of cutting the deck moulding right across about 9" back & lifting the nose off. It was then easy to chop the old plywood tang out & rebuild the area.
I chose to fabricate a new stemhead fitting with decent offset roller & central above deck forestay attachment point. The other side to the roller had a ring for an asymetric bowsprit. No more poncing about under the deck!

 

[anoccasionalyachtsman]

Here are @Samoddie's pictures..

 

[Samoddie]

Wow, this forum is good isn’t it! I am not sure what was meant about me not needing to read the post (one with pics) possibly it was a reference to how long your post was . I found it very helpful. I like aspects of whats gone on there. Not sure I am super keen on having nuts visible on the bow (Anderson’s are very pretty, as forum members may have heard....). Would placing countersunk screws through the thick glass of the bow be a worthwhile additional resilience?

On another note, how much thickness of glass do I need to add to the central fin to give it enough tensile strength. Appreciate it has to be woven fabric to work with resin. I think the moderator is going to add my pics, if the email address he sent is acceptable to the server. My worry is that there isn’t much of a surface area orientated in the same direction. Whole compartment is only about 9-10 inches high.

 

[Greenheart]

Wow...that anchor locker looks like a dream of ease, compared with reaching into the mostly-covered bow-locker of the Achilles.

 

[Samoddie]

Thanks dancrane. Read your bit again. As pics show, there isn’t an obvious way of either taking the force line to the stem (will need to check) nor, more importantly copying your solution without taking out the existing fibreglass fine like structure. The key challenge if I am to retain that structure is that it will be hollow, so will need protecting against compression forces of bolt if nothin else.

 

[Samoddie]

I had exactly this problem on an Anderson 22 that i virtually rebuilt some years back. Access to repair is very tight. I solved this by the simple expedient of cutting the deck moulding right across about 9" back & lifting the nose off. It was then easy to chop the old plywood tang out & rebuild the area.
I chose to fabricate a new stemhead fitting with decent offset roller & central above deck forestay attachment point. The other side to the roller had a ring for an asymetric bowsprit. No more poncing about under the deck!

@keith66 did you use glass to transfer load onto the original glass of the structure (ie central “fin”) or did you somehow otherwise transfer load to the hull?

 

[Greenheart]

Morning Samoddie.

I had replied pretty quickly when I read the word 'tang' in your opening post, believing that your problem was exactly comparable to mine...but then I looked at your photos, which show a slightly different scene from the tang issue aboard the Achilles.

That 'fin' structure under your deck seems (to me) to have been fitted to spread the upward load using the strength of the glassfibre bond to the floor and bow, rather than any solid anchor-point, though it also presents a small solid obstacle beneath the deckhead.

When I described my solution on the Achilles 24 owners' page there were flattering words in response, but people said as you have, that they'd prefer to rely on effectively gluing a strong-point to the inside of the anchor-locker, rather than use visible bolts outside the stem...

...I fully understand that, but I doubted my own ability and the ability of epoxy, to adhere securely and permanently to the very old flat GRP surfaces, in the perpetually damp rough-and-tumble of the anchor locker.

To me, it seemed that Butler Mouldings (who built the Achilles) had made a woeful job of the tang - because not only was it cheap short-lived unprotected metal, but the angle that the tang had followed towards the stem, was much too horizontal (its remains are the dark mess just visible above my bow U-bolt in the 'finished' photo...

...so even new, it wasn't providing the secure down-force that my fix now does.

I'm really a big fan of epoxy, foul toxic stuff though it is. But my solution didn't use any adhesive - just a well-spread anchor-point in the strongest spot available.

I may have misunderstood your description, but if the 'fin' is damp rotten wood encapsulated by GRP, I believe I would cut it all away before fabricating a solution. That GRP may be fine, or very moist too, so why take a chance?

If the floor of your anchor locker is fairly solid (mine in the Achilles felt thin, tremoring like a drumskin when chain landed on it) then I guess you could spread the load to the floor by heavily glassing a triangle of some tough non-absorbant material like thick acetal, into the extreme bow...

...then regard the acetal as a reliable strong-point to which your forestay can be extended below the deck, using a short rigging-screw and eye-plates.

Personally, I think the fin introduced more problems than it solved, because as well as presenting only a narrow surface to resist upward forces on the underside of the deck, it also conceals any ingress by water through the deck at the forestay foot, and didn't leave anything to check visually, or any access to enable repair...

...the fact that this is the anchor locker, means if there is ingress through the forestay foot bolt-holes by rain or sea, the water will drain below without causing problems...whereas putting the connection with the forestay foot inside the fin, required 100% waterproofing, which failed.

Sorry, far too many words for clarity. I'll edit it down to nothing later when I've read it through.

 

[anoccasionalyachtsman]

Morning Samoddie.

I had replied pretty quickly when I read the word 'tang' in your opening post, believing that your problem was exactly comparable to mine...but then I looked at your photos, which show a slightly different scene from the tang issue aboard the Achilles.

That 'fin' structure under your deck seems (to me) to have been fitted to spread the upward load using the strength of the glassfibre bond to the floor and bow, rather than any solid anchor-point, though it also presents a small solid obstacle beneath the deckhead.

When I described my solution on the Achilles 24 owners' page there were flattering words in response, but people said as you have, that they'd prefer to rely on effectively gluing a strong-point to the inside of the anchor-locker, rather than use visible bolts outside the stem...

...I fully understand that, but I doubted my own ability and the ability of epoxy, to adhere securely and permanently to the very old flat GRP surfaces, in the perpetually damp rough-and-tumble of the anchor locker.

To me, it seemed that Butler Mouldings (who built the Achilles) had made a woeful job of the tang - because not only was it cheap short-lived unprotected metal, but the angle that the tang had followed towards the stem, was much too horizontal (its remains are the dark mess just visible above my bow U-bolt in the 'finished' photo...

...so even new, it wasn't providing the secure down-force that my fix now does.

I'm really a big fan of epoxy, foul toxic stuff though it is. But my solution didn't use any adhesive - just a well-spread anchor-point in the strongest spot available.

I may have misunderstood your description, but if the 'fin' is damp rotten wood encapsulated by GRP, I believe I would cut it all away before fabricating a solution. That GRP may be fine, or very moist too, so why take a chance?

If the floor of your anchor locker is fairly solid (mine in the Achilles felt thin, tremoring like a drumskin when chain landed on it) then I guess you could spread the load to the floor by heavily glassing a triangle of some tough non-absorbant material like thick acetal, into the extreme bow...

...then regard the acetal as a reliable strong-point to which your forestay can be extended below the deck, using a short rigging-screw and eye-plates.

Personally, I think the fin introduced more problems than it solved, because as well as presenting only a narrow surface to resist upward forces on the underside of the deck, it also conceals any ingress by water through the deck at the forestay foot, and didn't leave anything to check visually, or any access to enable repair...

...the fact that this is the anchor locker, means if there is ingress through the forestay foot bolt-holes by rain or sea, the water will drain below without causing problems...whereas putting the connection with the forestay foot inside the fin, required 100% waterproofing, which failed.

Sorry, far too many words for clarity. I'll edit it down to nothing later when I've read it through.

Dan, the OP proposed laminating up a piece of grp to replace the ply, and I think that's more suitable than acetal (which would be tricky to bond). An all grp web is a very strong thing, but I certainly agree on chopping it all out and grinding everything back for a good bond.

 

[Greenheart]

Yes, acetal doesn't stick to anything easily. I was imagining a block of it being enclosed and secured within heavy glassfibre, so that the screws to which the new 'tang' could be attached, could bite through the glassfibre into something which is both very strong and impervious to waterlogging; but maybe a stub of epoxy and glassfibre webbing will do that equally well...

...but (apart from its small 'footprint' on the deckhead) it would still largely rely for its resistance to upward loads, on the bond between new and very old glassfibre.

Aboard the Achilles, it never occurred to me to make a single solid structure encapsulating the tang, as I understand Samoddie's boat has - and in retrospect I still think there's benefit in keeping the bolt-holes in the deck (which must be subject to eventual gradual water ingress) separate from the anchor-point.

I may yet be wholly missing the point.

 

[Gary Fox]

I thought he left after relentless ribbing about the A22?

That's rubbish, he loved the banter.
Who are you anyway?