Stemhead L Bracket to hull repair

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Stemhead L Bracket to hull repair

Postby W0QNX » Tue Oct 04, 2022 11:15 am

Hello all, I bought a boat or a "project" as most know when you buy an old boat. It's a mostly complete 1978 Daysailer II. It seems to be sturdy enough for me to repair and someday (soon I hope) to sail. I'm down here in Pensacola Florida so I have water to explore soon.

To the point, I've read enough on the forum to know how to check things out and look for problems before the first sail. I have found the Stemhead L bracket inside the hull just below the Stemhead fitting located on the foredeck is completely broken free of the factory "goop". The goop broke clean in half with the back half loose and the goop front half (forward of the brass L angle part) intact in the hull. I think I've read enough to surmise a repair of:

Gluing the L bracket down to the remaining goop with Sikaflex 292i.
Add a couple fasteners (1/4"?) through the front hull (just below the hull to deck radius) will work.
I may also add a plate running vertically (bolt to bolt) from the added lower L bracket bolt to the frontside U-bolt (tow hook) inside the hull.

Is this the correct repair method as of late?

So, is the Sikafex to the old goop OK? I doubt it adds much to the strength and I think the bolts through the hull suffice for strength. Nothing is broken yet other than the factory goop. You can see from the picture that I was able to remove the Stemhead fasteners and the brass L bracket is fine.

Also while I'm in there is the board the "tow" U-bolt passes through a piece of plywood? How thick? I'm thinking if it is easy to remove the plywood and replace it now I should do that while it's opened up. I think that needs glassed up and replaced right?

Does that look like the old single bolt threaded tow eye just above the U-bolt? It doesn't pass through out the hull so I guess it can be remove with the board.

I'm pretty able to do most any kind of wrenching or work and have done that lifelong but fiberglass will be a new venture for me.

Picture is looking to the front inside the hull with the L bracket goop at the top. Two holes with the sunlight are the Stemhead bolt holes in the deck. Right click on pic and open for a bigger picture.

Image
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Re: Stemhead L Bracket to hull repair

Postby RaleighRancher » Wed Nov 16, 2022 9:51 am

I don't know the "correct" way, but I had to do a similar repair this summer after accidentally tearing the forepeak deck up from the hull. (Here's that threadhttps://forum.daysailer.org/forum/viewtopic.php?f=11&t=6716, with lots of helpful suggestions by Greenlake.)

What I ended up doing was to scrape away all the old goop and sand down to bare hull on the inside, extending out a few inches to each side. I drilled two holes in the stemhead L bracket/tang, tapped them, and put in a pair of stainless steel screws. Then I reinstalled the stemhead tang. Then I prepared about two cups of thickened epoxy to mayonnaise or hummus consistency (or your equivalently thick deli condiment of choice) and put that in a plastic bag. Cut the corner from the bag and squirted the epoxy behind and all around the tang. Then I wetted out a 2" wide band of fiberglass cloth and bedded that into the new epoxy, in between the two new screws in the tang, and out onto the bare hull. I'm thinking the screws and the glass cloth were probably unnecessary. The key to the whole thing is whether I managed to get a good bond between the epoxy and the hull. Time will tell.

The other approach that I contemplated strongly was to install a brass bar from the tang down to the back of bow eye. That would've required less prep and certainly would be quite permanent. Ultimately I was a little unsure about how the dynamics of the forestay and the bow eye might interfere with each other and opted for an approach that was closer to the factory original.
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Re: Stemhead L Bracket to hull repair

Postby GreenLake » Wed Nov 16, 2022 2:45 pm

The idea of tying to the bow eye isn't a bad one. It would certainly be extra strong. Not sure about brass. Bronze maybe.
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Re: Stemhead L Bracket to hull repair

Postby W0QNX » Tue Nov 22, 2022 12:09 am

I'm guessing this forum is near dead for reads and replies.

I did the repair back maybe Oct. 10th. Added the Sikaflex and 2 bolts out the front and a stainless strap down to the bow eye bolt. Probably stronger now than it was new with the bow eye strap.
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Re: Stemhead L Bracket to hull repair

Postby GreenLake » Tue Nov 22, 2022 3:25 am

What can I say? I have access to the logs from the hosting service, and they show a consistent rate of people visiting, and there's no obvious trend in the number of page visited or bytes of data downloaded. If anything, we are on target for a bit of an increase in the number of GB of data transferred in 2022 over 2021. This is true even though there seem to be fewer people posting, at least we've lost a few of our more active contributors due to life changes or boat upgrades. The forum software is not particularly mobile friendly. Which is something we could look into.

Glad your repair works for you and I agree what you have should be stronger than factory original.
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Re: Stemhead L Bracket to hull repair

Postby W0QNX » Wed Nov 23, 2022 10:27 am

I'll post what I did to make this repair.

I worked out the position of 2 each through drilled 1/4" holes to be added into the Bow front just below the top deck joint curved lip. I drilled the top hole only so I could measure down inside and be sure the second hole would fall on the lower area of the L bracket. I placed the L bracket back in place "loosely" with new bolts ran down through the upper deck. I then held the factory Bronze "L" bracket back into the original position of the L bracket depression left in the factory goop (I pushed against it with a board) and then start drilled (marked) the L bracket for the first hole. I finishing the hole in the bracket after it was removed from the inside held position. With one hole in place I measured the length needed to keep the second hole on the L bracket and then drilled the second hole from the bow front. I then bolted in the L bracket back in with the top deck bolts and the first new bow (top) 1/4" hole and start drilled the bow second hole, remove it and finished drilling it after removing the bracket from inside.

So my new top deck chainplate bolts are in the original factory position (the factory bronze L bracket is tapped to 1/4") from above and the new drilled bow bolts come in from the front. Ready for some "glue" and tighten things up.

I positioned the factory Bronze "L" bracket back into the original position of the L bracket depression left in the factory goop and inserted the new chainplate 1/4" bolts down through the deck to the L bracket NOT TIGHTENED DOWN. The L bracket DOES NOT TOUCH THE DECK BOTTOM on my boat. If the L bracket is back in the factory position there is a gap from deck bottom to L bracket top. I added glue (Sikaflex 292i) onto\around the L bracket and placed it into the depression left in the factory goop. I installed the new bow through bolts and tightened them up. Since I was gluing back to the old factory "goop" I feel the expensive sikflex 292i was a waste of money over regular Sikaflex. The glue joint is no stronger than the factory (deteriorated) goop. YMMV here.

The lower new bow bolt has a 1"? wide by 3/16"? SS strap installed and a second nut added to secure the strap at the top. The strap runs down and fastens to both bolts of my bow tow line U bolt eye with second nuts over the U bolt nuts.

I've only sailed the boat twice since the repair so I can't claim much yet but I think this bolt up method is probably stronger then the original O'day design.

Right click on pic and open for a bigger pictures.

Image

Image
Last edited by W0QNX on Fri Nov 25, 2022 9:55 am, edited 1 time in total.
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Re: Stemhead L Bracket to hull repair

Postby GreenLake » Wed Nov 23, 2022 5:56 pm

Very nice. The only thing I'd like to double check with you is whether you used any TefGel, Duralac or other galvanic insulator where SS is in contact with bronze. Always a good idea when you have dissimilar metals, but perhaps not quite as critical as with an aluminum/SS common to mast and boom fittings. And not exposed to the elements in this case.

I don't understand the significance of the gap below the foredeck. It doesn't strike me as a feature, more like an accident of sloppy manufacturing. As long as the stemhead fitting doesn't move when you tighten the forestay, all should be well.
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Re: Stemhead L Bracket to hull repair

Postby W0QNX » Fri Nov 25, 2022 8:54 am

I did not use any insulator on the threads. I may go back in later and do that.

I think the L bracket to deck gap is because the L bracket was set and glued in to the hull front before the deck was set in place and joined to the hull. It's also hard to see from the photo but the L bracket is not even parallel with the deck. I'd guess about 5 to 7 degrees difference in the parts both left to right and fore and aft. There is no access into the front area through the forward bulkhead at the factory assembly time point. No pass though hole in front until "we" add it on a DS2. Right?

I think per design the DS2 has a sealed chamber below the cuddy and floor decks stem to stern other than the floor ports and rear transom drain hole which is plugged up during sail. I'm guessing the boat top deck was set in place last after they filled that front area with the foam pieces.

I reckon they left the L bracket down a bit so it will not touch the deck bottom during mating of parts to NOT hold the hull to deck radius joint "gapped up" anywhere. I think the reason you see some of the L brackets with the 2 deck bolts drilled so far off center is because they are drilled blind down through the deck after the deck install. And those holes are tapped as there is no access for nuts under the L bracket. The deck adds no strength to the load route? of the path from bottom to top (hull to mast attach point). And that front hull L bracket held with the "goop" is the weak point with time. What is that goop anyway? Mine looks like old auto Bondo. My load path now goes from the bow tow eye bolts to the mast attach point.

The L is tapped so the stem chainplate bolts are like vertical extensions of the load path rather than "tightening the deck to the L bracket" bolts. That is also why I added the nyloc nuts beneath the L bracket. Mine should not come loose in the future.
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Re: Stemhead L Bracket to hull repair

Postby W0QNX » Fri Nov 25, 2022 9:41 am

Maybe these pictures will help explain the gap I left in my repair. From the factory it appears the L bracket is glued in place with the goop before the deck to hull mating. It is simply set into a glob of goop (slightly below deck height) and covered with more goop. No bolts placed through the front of the hull which I think would add a LOT of strength to this assembly.

The first picture shows how the L bracket was found when I bought the boat. The stemhead bolts down through the deck had been tightened up closing the deck to L gap and bringing the L up to the bottom of the deck away from the factory glue point at the bow. Note the (3/4") space at the bottom of the L showing the distance the L had been moved up out of the glue joint. This makes it clear to me the L does not need to be against the deck above. I was also counting on the Sikaflex conection of the L bracket to old goop area to create a bond holding the L at the correct point for repair drill holes and strength. Knowing what the glue (goop) quality is now (poor) I doubt this joint adds much strength hence the bolts needed passing forward through the hull.

The second picture is the back half of the goop I found inside the fore hull area mixed in with the foam blocks when I removed all the foam. This goop should have still been covering the back area over the L bracket but had broken free. I would guess when this stuff broke and the L bracket hung free inside the previous owners tightened the chainstem bolts up tight.

Right click on pic and open for a bigger pictures.

Image

Loose back half of the goop joint.

Image
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Re: Stemhead L Bracket to hull repair

Postby GreenLake » Fri Nov 25, 2022 6:18 pm

Very clear explanation, and hopefully useful to all who come later to read the archived discussion.

I think your reconstruction of how/why this was put together this way are very convincing. Obviously, the whole point of the L bracket is to offload the deck, so that certainly works.
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