Install Bow Eye-Bold on Fixed Keel Sailboat

[Mistress Sirena]

They make them in 1/2" allso rated at 10000 lbs make up backing pad from FG roving
12X12--10X10--8X8--6X6--... grind the area you want to place the U bolt wet out all the pieces with good epoxy .will hold the whole boat no problem .

[Time2Go]

Having just moved my ODay Mariner today and assisting with a few other boats
Most had the winch on the trailer set to match the height of the eyebolt on the
boat. You don't want the winch pulling up or down but straight on.
Helps to keep the boat even on the trailer bunks

[UNCIVILIZED]

+1 on adding successive layers of reinforcements & epoxy, although I'd recommend something a touch stronger, & easier to laminate, like alternatingly angled patches of heavy tri-axial glass.

If you like, in order to create a more flat surface, inside, for the backing plate, post glassing. Get a block of G10, & grind it to fit the taper on the inside of say, the front 2"-3" of your hull. Then glue it in place with some epoxy mixed with milled (fiberglass fibers) AKA "Bog". And then start your glass reinforcement on top of it.
Although it might be wise to drill undersized holes through the block & hull, from the inside out, all of the way through both the block & hull, prior to starting your glass pad.
They'll serve as guide/pilot holes later on.

In terms of how to lay up your additional reinforcing. Just keep adding layers on in slightly bigger pieces, at alternating angles, so that each one has a good, independent area of contact with the hull.
The alternating the patch layup angles at 30, 45, or 90 degrees to one another, help with this.

If you have to stop part way through the laminating, no worries, just put a layer of peel ply on when you stop for the day. That way, when you come back, & everything's cured hard, but you still have more glass to add, you just pull off the sheet of peel ply, with no worries about amine blush to remove, or needing to grind before starting to glass again.

Once you get your thickness where you want it, use some door skins & a hot glue gun to make a mock up of the backing plate. This method will let you get the angles (and hole placements in it for the bolt all laid out & drilled in advance). That way, you can take the mockup to your shop, or the hired out shop, & make the angles in the plate fit the boat on the first try.
Plus, & you can also drill a few small mounting holes in the backer while it's on the work bench, in addition, of course to the primary holes in the backer.

FYI, it pays to have the primary holes in the backing plate (backer) drilled a little oversize, as the holes which you drill in the stem are never perfectly straight. So this gives you a little wiggle room for fit. And the hefty washers on top of the backer, underneath of the nuts, cover up this small gap.

From there, were it me, I'd fully drill through the holes in the bow, & dry fit everything. Then mix up some bog. Tape off the area around where the metal backer will go, & apply a 4mm or so layer of bog, to thus create a perfect(ly) molded, & mated LZ for the backer.

Then bolt everything together lightly, to create said, perfect backer mounting pad, after making sure that there are a couple of layers of some type of stout mold release on the bolts & nuts.

After that, walk away, & let things cure. Later, you can glass over the plate if you want things to be stupid strong.
-There's a section on epoxying metals in the WEST System guides.
And once that's all done, apply a bit of bedding compound (or not, if you use the bolt with the boot from Wichard).

Then it's time to crack open a couple of cold ones ;-)


PS: You can go with a non-booted bolt, & either use your own favorite sealant to keep things watertight. That, or put a bit of modeling clay around it's holes on the outside of the boat as a temporary seal. And fill in the gaps around the bolt's legs, inside of the boat, with neat resin.
Although for this, you have to build small cofferdams (with modeling clay) around the bolts on the inside of the hull, so that you have a cavity under & around the bolt which will hold the resin while it cures.

Ah, and here are some of your bolt choices, from Wichard anyway. I favor/recommend the U-bolts with the factory rubber boots. Fastenings
Were she my boat, I'd adorn her thusly http://marine.wichard.com/fiche-A%7C...000000-ME.html
Often enough, for small quantity purchases, I get glassing supplies at reasonable prices here www.fiberglasssupply.com in addition to the supplies bit, they're some very nice as well as helpful folks.

[UNCIVILIZED]

Dan,
Not to monopolize the thread, but I reread your posts, & ID'd a few more problems which you mentioned.
If working space up forward, inside, is stupid tight, you can go with a bigger, differently shaped G10 unit than I first suggested. Perhaps even to the degree of making a door skins & glue mockup of the inside of the bow, prior to doing any reinforcing.

Then use the mockup to build a G10 version to fit inside of the bow. This one would be pretty much triangular in shape, albeit, perhaps be flat up front for a short distance/space. And it'll have a top & bottom to it, as well. With the G10 tapering at it's aft edges, especially where they meet the hull sides.

From there, you'd first bond your G10 box structure into the bow using bog, along with a pair of temporary (disposable) bolts to hold it in place as the bog cures.
Followed by tabbing the block into the hull with successively larger pieces of pre wet out tri-axial cloth. And you can put each piece of wetted out cloth onto a piece of Viaquene for ease of handling.

I'd say 3-5 layers of triax on the top, bottom, & from the insides of the box out onto the hull should be sufficient. And it'll make for less laminating, & thus less working in the bow.
The extra strength in that region of the hull will come from the thicker & larger pieces of G10 carrying the load. And your G10 "box" needs to be tall enough to accept the backing plate which comes with the U-bolt.

Just make sure to use good gluing practices, particularly with the G10 box to hull interface. And to make sure that there's a good taper to the G10 where It meets the hull, so that you're not creating any substantial hard spots with it.

Aside from that, installing the U-bolt's already been pretty much explained.

Also, it's pretty easy to extend the tongue of a trailer. Mostly, all that's required is a section of box beam, & some large "U-bots" which are square in cross section. And you can even revert the trailer to it's "normal" length with a bit of wrenching, when you need to.

PS: I know that it's kind of obvious, but when you're building the G10 box, ease/bullnose all of it's outside edges, & tape them up well. And on the inside, lay in some bog filets around the corners, & tape them like the ones on the outside.

[Terra Nova]

UN--I believe you might be over-thinking this installation.

[UNCIVILIZED]

Originally Posted by Terra Nova

UN--I believe you might be over-thinking this installation.

Yeah, odds are you're right.

[JPA Cate]

Originally Posted by Terra Nova

UN--I believe you might be over-thinking this installation.

Aw, I dunno TN... you never know when the OP might fill the boat with concrete and steel punchings and then want to lift the whole thing vertically by the bow eye! Can't be too strong, ya know...

And for the OP: years ago I had a Catalina 22. It had a single screw bow eye, 3/8 inch diameter , that was simply stuck through the hull layup with a cluged up fender washer on the inside for reinforcing. Never gave a problem, and those very early Catalinas were not known for "overbuilding"!!

IMO you are not very likely to generate very high stresses with a typical trailer winch setup, even when pulling her out of the water.

Cheers,

Jim, using Ann's computer.

[Danmcgaffin]

I'm not sure what a fairing pad is. Would that be similar to a backing plate, but installed on the outside of the hull?

[FlightPlan]

Originally Posted by Danmcgaffin

I own a Tanzer 7.5 sailboat which is just under 25 feet long. It has a fixed keel and was designed to be launched and retrieved with a crane, so it doesn't have a bow eye-bolt. However, I keep the boat every summer at a state park lake where there is no crane to place the boat onto my cradle trailer during retrieval in the fall. Although the water depth at the launch ramp is sufficient to allow the boat to be floated directly over the pads before pulling the trailer out, there is no really good way to prevent the boat from sliding back into the water as the trailer is towed up the launch ramp. Therefore, I am hoping to be able to install a first-time bow eye-bolt that can enable holding the boat into place with the trailer winch.

My two main concerns with this project are 1) whether and how an eye-bolt should be installed without damaging the hull and 2) at what location the eye-bolt should be installed relative to the waterline and the rub-rail. I am told that Tanzer built rather thick and solid hulls, but I am not confident I can safely add an eye-bolt to a boat that was not designed to have one. FYI, two photos from winter storage are attached that show the relative configuration of the water-line, trailer winch and rub-rail.

I am open to opinions/suggestions on whether, how, and where to install a bow eye-bolt. Maybe it shouldn't be done at all and I should continue to muddle through by holding onto bowlines while lying back in the pickup truck as it pulls the trailer up the launch ramp.
Thanks,
Dan

I would take a line from the port winch to the hitch with a turning block then back to the starboard winch. I would not trust an eye bolt in the keel.

[Terra Nova]

Originally Posted by Danmcgaffin

I'm not sure what a fairing pad is. Would that be similar to a backing plate, but installed on the outside of the hull?

Inside the boat's stem will be a mirror image--a female V, instead of the male V which is the bow of your boat. Rather than fabricate a skinny backing plate to fit the bottom of this V, it is recommended that you fill the sharp V section with a sufficiently thick block to allow for a larger flat backing plate, and to spread the load on the backing plate over a large enough area.
Bow eyes usually come quite long enough to allow for a good thickness.

[SkiprJohn]

Just to let you all know that his boat weaighs about 4500 lbs with all gear aboard. He is not going to be lifting the boat by the bow eye or dragging it through a field. He is going to be adjusting it on a trailer and preventing it from sliding backward as he drives.

You don't need 1/2" u-bolts or eyes. You could use 5/16 or 3/8. You also don't need to build up the interior of the hull. At the v it is plenty strong with overlapping layers of glass. You could add a bit of epoxy filler to flatten the area where your backing plate would rest to give it more uniform strength but again it is not needed if you bed the whole thing in 4200 or 5200.

Of course that's just my opinion.

[SkiprJohn]

Originally Posted by SkiprJohn

Just to let you all know that his boat weaighs about 4500 lbs with all gear aboard. He is not going to be lifting the boat by the bow eye or dragging it through a field. He is going to be adjusting it on a trailer and preventing it from sliding backward as he drives.

You don't need 1/2" u-bolts or eyes. You could use 5/16 or 3/8. You also don't need to build up the interior of the hull. At the v it is plenty strong with overlapping layers of glass. You could add a bit of epoxy filler to flatten the area where your backing plate would rest to give it more uniform strength but again it is not needed if you bed the whole thing in 4200 or 5200.

Of course that's just my opinion.

Anchored in a hurricane would be a different story.

[Dave Lochner]

Originally Posted by SkiprJohn

Just to let you all know that his boat weaighs about 4500 lbs with all gear aboard. He is not going to be lifting the boat by the bow eye or dragging it through a field. He is going to be adjusting it on a trailer and preventing it from sliding backward as he drives.

You don't need 1/2" u-bolts or eyes. You could use 5/16 or 3/8. You also don't need to build up the interior of the hull. At the v it is plenty strong with overlapping layers of glass. You could add a bit of epoxy filler to flatten the area where your backing plate would rest to give it more uniform strength but again it is not needed if you bed the whole thing in 4200 or 5200.

Of course that's just my opinion.

SkiprJohn, mostly I agree with you. Better to use ⅜", a very small increase in cost for more strength. The backing plate needs to be flush against the hull so some fairing might be needed, but probably not much.

The OP should give the next owner a break and avoid the devil's caulk (aka 5200) This is a fitting that may need to be rebutted at sometime and the location and 5200 will make that next to impossible.

[Danmcgaffin]

SJ and DL, I agree with the 3/8" recommendation and using 4200 instead of 5200. I won't know what the inside of the stem looks like for a few weeks since the boat is blocked in by several other boats in the indoor winter storage facility. However, if it's necessary to build up a flat surface on the inside of the stem I haven't made up my mind on what material to use. I guess the choice of whether to use fiberglass, patching compound, fender washers, etc. will depend on the shape and thickness of the stem. I think it would be best to keep it simple without compromising the integrity of the U-bolt. I know I'm the OP but what does OP stand for? Thanks.

[Dave Lochner]

OP = original poster