Attaching Tie-Downs to Fiberglass

[Dockhead]

I am trying to install a new tie-down for my life raft inside the life raft locker on my boat, just for some added security.

The obvious thing to do would be to drill through the deck with a couple of eye bolts and backing plates and be done with it.

But putting unnecessary holes in the decks of plastic boats is something I have a passionate aversion to doing. So what if I glass in a couple of eyes on the surface of the deck (this is inside the locker so not visible) instead? Is it possible to make such an attachment reasonably strong? There is a flat smooth surface I could do this on.

[Bill O]

How about a SS helicoil insert? Not certain what you are mounting it to (f/g over wood?), but could drill out and fill w/epoxy then set your threaded insert.

We've done this on deck w/some HDU board and is working well to hold down hardware.


Bill O.

[estarzinger]

there is a whole range of adhesive padeyes, depending on the strength you need.

Click bond is one of the leading brands at the medium strength area https://www.clickbond.com/product-de...-tie-down-ring

the whole click bond line is good to know about - for cable routing and ties and mounting studs, and so forth - extremely fast and easy to use and reliable.

Ropeeye at the higher strength https://www.ropeye.com/shop/ropeye-xs / https://www.velasailingsupply.com/ou...eye-soft-eyes/

You can self-fabricate these pretty easily at a low lower cost if you know what you are doing (re adhesives and simple tool use). (for the 'no hole' 'stick on' model) Rope eye essentially spreads/fans out the dyneema fibers and then glues them in a sandwich between two pieces of carbon plate. For higher strength 'thru hole' models often a knot is used which can't pull thru the hole.

[Bill O]

Originally Posted by estarzinger

there is a whole range of adhesive padeyes, depending on the strength you need.

Click bond is one of the leading brands at the medium strength area https://www.clickbond.com/product-de...-tie-down-ring

the whole click bond line is good to know about - for cable routing and ties and mounting studs, and so forth - extremely fast and easy to use and reliable.

Ropeeye at the higher strength https://www.ropeye.com/shop/ropeye-xs / https://www.velasailingsupply.com/ou...eye-soft-eyes/

You can self-fabricate these pretty easily at a low lower cost if you know what you are doing (re adhesives and simple tool use).

Click bond has a fairly versatile line of attachments. Thanks for posting.

Bill O.

[Colin A]

You could laminate in some G 10 and drill and tap it.

[HopCar]

I’ve epoxied a block of wood to fiberglass and screwed into the wood. It was a pretty strong mount.

[Dockhead]

Thanks for all the excellent ideas!!

What Colin A suggested is kind of what I had in mind, and I wonder if anyone has actually done that.

But ClickBond opened a whole new horizon for me! I didn't know about these. There are many uses for something like this on my boat. I am looking for a source in the UK.

[Almost-There]

I just lost a long post but here's the short version.

Cut a hole in the top skin about 3inches around the fasteners location.

Remove the core and prep the surface for epoxy.

Feather the outside edges like you're doing a structural repair or as close as possible.

We used to use large washers welded to the nuts. But if you can't weld them you can use flanged nuts or just set the washers on top.

Thread some old bolts in and either cover the threads in tape or hot glue.

Mix some thickened epoxy and fill the void with the nuts and washers in place.

Once its cured make sure you can unscrew them but don't take them out just yet.

Now its time to cut some glass mat in progressively larger sizes corresponding with the beveled area. Glass them in like a structural repair .

Now add some filler and fair the area smooth.

Remove the old screws and thread in your eyelets and you now have a VERY strong mount without holes to the inside.

Depending on how big you go and the backing etc you can mount some heavy loads like this . It's especially good for places where its gel coat inside and you don't want screws showing .

[Halien]

I've used a variety of Weld Mount fittings on my boat. So far they appear to be indestructible with regular use.

[foufou]

I've attached a thimble to a mast using a piece of glass cloth with epoxy. The thimble was for 3/16 line. The cloth was about 3"X 8". I pulled the middle third cross fibers out. Epoxied the cloth. Then twisted the middle into a rope. Placed the rope around the thimble and pasted the remaining flat parts together and onto the mast. This part held forestay and shrouds on a 20' mast. Sailed hard for over ten years. Very strong. And inexpensive. Try a practice part first. I hope this brief description makes sense

[Chuck Hawley]

Originally Posted by HopCar

I’ve epoxied a block of wood to fiberglass and screwed into the wood. It was a pretty strong mount.

I like this approach. First, secondary (post-cure) bonds to fiberglass are pretty ineffective unless you're careful. You want to have a clean, relatively flat place to do your bonding, and to use some thickened epoxy to smoosh together between the wood (or G10) and the surface. Your wood block (or other material) should have tapered edges so you can avoid voids along its perimeter. Then you should cover the block with a few layers of glass and epoxy to spread the load over a larger bonding area.

Not easy to do in the confined spaces of locker, bilge, etc. However, it should get you a very secure place to mount a padeye or cleat or whatever.

If you were very clever, you might be able to insert some T-nuts in the proper orientation in the wood, bond the wood in place, then uncover the T-nuts, but that would be more challenging.

Cheers,

Chuck

[meirriba]

Do I understand correctly that you store the L/R inside a locker?
I would prefer it to be mounted in a visible and easily accessible position (e.g. on stern pushpit or something comparable).
Apologies if I misunderstood...

[Almost-There]

Meirrba,from his description he's trying to fasten it down inside a locker that is on deck to keep it from moving around.
Some boats are equipped with lockers on deck just for life rafts and life preservers etc.

[roverhi]

Originally Posted by meirriba

Do I understand correctly that you store the L/R inside a locker?
I would prefer it to be mounted in a visible and easily accessible position (e.g. on stern pushpit or something comparable).
Apologies if I misunderstood...

The problem with deck mounting life rafts is they can be swept off the deck by breaking waves. If you are going to mount a raft on deck better make the lashing points super strong and hope a breaking wave doesn't rip off some of the deck along with the raft in seriously bad weather.

[Jim Cate]

Originally Posted by meirriba

Do I understand correctly that you store the L/R inside a locker?
I would prefer it to be mounted in a visible and easily accessible position (e.g. on stern pushpit or something comparable).
Apologies if I misunderstood...

I suspect that DH's efforts here are related to the recent event chronicled here where a Petersen 44 was knocked down by a boarding wave and the externally mounted life raft was swept away.

Sobering thoughts considering his upcoming cruise to Greenland... I don't blame him for being conservative with essential lifesaving equipment!

Jim