Forestay Fitting Backup Structure Failure

[Bluenose]

Yesterdays wonderful sail turned a bit south just after we saw that beautiful Six Metre again. I was on the foredeck and notice that the headstay fitting had lifted off the deck. Resisting the urge to panic we turned around and headed home. I attached the jib halyard to a pad eye I install for the cruising chute and took a look at the damage.

So it turns out that the backup structure that holds the forestay fitting to hull had failed. I didn't have my camera so I won't have picture for a bit, but it apears that the structure had gotten wet and finally failed. Here is a quick sketch of what I think is going on.



My goal is to get out and get some pictures and I will pass them along asap. I would love to hear from anyone who has seen an elegant and simple setup for this type of backup structure. I am not to keen to replicate the existing setup.

Thanks, Bill

[Tim]

I'm not quite clear what's going on with the current setup, so pictures will probably be a huge help when available.

[Bluenose]

OK, Pictures are in. And the first obvious fact is that this failure gave lots of warning. Water marks showing a long history of leaks. Definately my bad for not getting to this sooner. It is in a challenging location to inspect but still. I definitely dodged a bullet this time.

Here is a view looking forward in the "v-berth".



And a closeup of the failure.



Here is a picture of the top of this backup structure. Really the only thing keeping the mast up was the fact that this hunk of wood crap was trapped below deck.



If there is one good thing it is that rotted wood comes out easy. I loaded a bunch of tools into the dinghy ready for a struggle and removed this mess in 10 minutes.



Here is what is left of the head stay backup structure. On top you can see how the head stay fitting is sandwich between two pieces of what used to be wood.



Here is a photo of the deck.



I am off to the mainland tomorrow for epoxy and fiberglass supplies. It should also provide ample opportunity for some thinking about my repair options. This will be my first fiberglass repair job so I welcome any advice.

Thanks, Bill

[Duncan]

Your description was very good, to the extent that the photos confirmed just the way you had described it in words.

Fools rush in where angels fear to tread, and I don't have any expertise in this, but I have a feeling you might be just as well off to replicate the original structure. This is just food for thought, but the original design seems none too bad - it ties in the hull and the deck together at very strong points for each. In that sense, it's pretty well-conceived. The failure was long term, and due to degradation of the material, not structural weakness in the design.

There are, of course, plenty of ways this could be re-engineered, but the only problem identified was that the material eventually failed due to water intrusion and rot. I'd therefore be inclined to rebuild it the way it was, but to give the wood a good soaking of epoxy plus a couple of layers of glass. That should encapsulate the wood, i.e. make it far less vulnerable to rot. This way you solve the problem, without creating any new ones by doing a new design that might have unforeseen consequences?

I guess it wouldn't hurt to reinforce the underside of the deck, give it a big triangular backing plate, and tab that into the vertical supports, but that might be overkill.

Anyway, this is just thoughts, but I guess my point is that I'd hate to mess with something that seems to have worked very well in the first place. This is based on thinking that it only failed because it couldn't have been expected to last forever, and, as you say, because the signs of deterioration weren't immediately obvious.

I'm very glad it failed without you losing the rig, which would have ruined your whole day!

[catamount]

I think the key thing to remember as you put this back together that it serves primarily in tension, counteracting the upward pull of the stay on the deck. An alternative might be some sort of tie rod (or stay) running from the underside of the deck fitting down to an eye (or other fitting) thru-bolted (or otherwise strongly attached) inside the stem. You could rig this up with a bit of rigging wire that matches or exceeds your stay, an appropriate turnbuckle, and the right terminal fittings (forks, eyes and/or toggles).

Good Luck,

Tim A.

[Bluenose]

I managed to pick up my supplies from West Marine and still make the early ferry home. So I tore into the backup debris. The bolts holding the headstay fitting were just about rusted through. On quick twist of the nut and they sheared right off. It did, however, take a few determined nudges with the hammer to get the remains out of the holes. Then I had to tackle the headstay fitting with a little sand paper for some instant gratification.





Thanks Duncan

There are, of course, plenty of ways this could be re-engineered, but the only problem identified was that the material eventually failed due to water intrusion and rot. I'd therefore be inclined to rebuild it the way it was, but to give the wood a good soaking of epoxy plus a couple of layers of glass. That should encapsulate the wood, i.e. make it far less vulnerable to rot. This way you solve the problem, without creating any new ones by doing a new design that might have unforeseen consequences?

and catamount

I think the key thing to remember as you put this back together that it serves primarily in tension, counteracting the upward pull of the stay on the deck. An alternative might be some sort of tie rod (or stay) running from the underside of the deck fitting down to an eye (or other fitting) thru-bolted (or otherwise strongly attached) inside the stem. You could rig this up with a bit of rigging wire that matches or exceeds your stay, an appropriate turnbuckle, and the right terminal fittings (forks, eyes and/or toggles).

for the ideas and suggestions. I pondered them during my ferry rides. I have to confess that my first idea was to replace the current setup with wire rigging. But now I am leaning toward replacing the current structure with a little more water proof setup. I still have a bit more time to ponder. I have arrange to rent a temporty slip at one of our local docks so I won't start the real work until next week. I almost decided to do the work on the mooring but then came to my senses.

[Tim]

The key to longevity with any structure--no matter what it's made from--is to avoid long-standing contact with water. Clearly, what started the process here, and eventually led to the failure, was long-term water infiltration through the deck fitting. The original structure may have left something to be desired in terms of execution and overall quality, but it still did pretty well for a long time.

Chainplates are tough to seal well at the deck because they tend to require long slots, and the loading is dynamic, causing the structure to move naturally. So regular resealing of any chainplate penetration is a must, but is frequently neglected. A lot of bulkhead and knee failures occur from ignoring the simple task of rebedding.

Wood is strong and easy to work. If it'd been kept dry, I imagine the original wooden structure here might have lasted essentially forever. Perhaps there are better materials to use now, and certainly you should consider all avenues, but don't necessarily overlook wood as a structural material only because years of neglect caused a very old structure to eventually fail. It looks to me like there were plenty of signs of impending doom before the failure occurred.

Other construction options here that I immediately see might be to replace the wood with a structural composite like Coosa board, or to use tie rods of wire rigging or rod stock. Creating a longitudinal bulkhead that extended further forward into the stem would allow more bonding area for tabbing to strengthen the eventual connection at the hull and deck, instead of the sort of free-standing structure in the original setup. I'm sure there are other considerations here as well, which may not be evident from the information at hand.

Everything requires maintenance, and good maintenance will make just about anything last for a very long time.

[Bluenose]

Everything requires maintenance, and good maintenance will make just about anything last for a very long time.

Tim you are very right about this. My Bluenose is my first sailboat and I purchased her from a self professed professional boat builder. Without knowing anything about boats I doubted this right off. I found myself in a position to do work that I was inexperienced to do and was and am in a bit over my head. I did a lot of work just to get her into the water but in hindsight my priority list was skewed towards splashing. Reading this site and watch you restoration work has provided me with some insight and confidence to try things that had been pretty intimidating.

About wood, what type would you choose?

[Summersdawn]

What about GRP panels? They are strong, you won't have to worry about rot, and bond well.

[Bluenose]

Since I had some time before the slip I had reserved became available I went to work recreating the wooden backup structure for the headstay fitting. I had decided to basically recreate the existing fitting but try to enhance the structure to be more water resistant if the headstay plate fitting leaked through the deck in the future.

My first decision was to use a solid piece of wood in lieu of the sandwiched plywood construction of the original. I matched the existing shape of the original wood and cut a notch in the middle to accommodate the headstay plate.

On Sunday evening the slip at the Galley Dock that I had arranged to use for my repair became available. So we rowed a short distance from the mooring and set up electricity. Monday bright and early I ground away most of the old bedding compound and fiberglass that supported the old plywood backup structure and carefully fitted my new piece.

Now that I had it fitted in place I marked the location of the headstay plate and drilled the holes. I replace the existing steel boats with stainless and coated the wood in epoxy. I also decided that maintenance wasn?t as important as longevity so I filled the slot with a mixture of 404 filler and epoxy.



This morning we mixed up a batch of 404 filler and epoxy and I filled in and around the existing bedding. This was my first real epoxy work and it turned out better than I thought it might







Finally, a headstay fitting. Although we still have a ways to go.



Tomorrow?s plan is to lay up fiberglass between the post and the sides of the hull. This will again be a first.

[Jason K]

Bill,

As you may know, you'll want to sand a smooth radius in the epoxy before you lay down the fiberglass. The 404 filler can be tough to sand, so you may want to be sure you have some fairly aggressive sandpaper on hand to deal with the more prominent peaks and ridges in the epoxy. Also, wipe the epoxy down with a wet cloth to remove any amine blush, this will help ensure that your glass bonds well.

Thanks for the photos and the updates - keep 'em coming!

[Bluenose]

Thanks Jason,

Good advice. I think I have some old 50 grit from a belt sander I never fell in love with. I think I will cut it up and wrap it around a PVC pipe and make a sanding block, I mean tube out of it. I am starting to get excited about this project. Excitement combined with my level of experience is probable dangerous, but what the heck. Tonight the new wife is cutting out the fiberglass layout patterns (she took a pattern making class for goodness sake!). Am I lucky or what. Two boats and she helps with repairs.

Cheers, Bill

[Bluenose]

Finished!! Today was such a nice fall day for sailing that I put off bedding the cover plate until after a short sail. No pictures yet of the my first fiberglass job (I was too Jonesing to go sailing) but here is the track of our "test" sail (New Garmin GPSMAP 76S). The normal South wind took a holiday and let the West wind play which is perfect for sailing in and out of Fisherman bay. A nice break form the usual tacking dual through the narrow channel.



The crazy loop was to sail around a beautiful Bristol Channel Cutter from Friday Harbor. Another great day for sailing up in the San Juan Islands and it was just the two of us and one other sailboat motor sailing off in the distance. If anyone is thinking about coming up here to do a bit of sailing and cruising, bring a sweater and think about late summer or fall. No crowds, great wind but just no promise of only sun.

Bill