DIY Ropeye deck eyes?

[paulajayne]

Design your fitting to take a brass cap on the underside - knot can be inside it.

Have a look at tank fittings - a reducer fitted in the top will give a good rope stop.

HTH

[atmartin]

Originally Posted by mrybas

No, still trying to figure that one out. The button knot will be tight against the g10 backing plate, so this seems like a tough spot to try and make watertight. Maybe its easier to try and waterproof from the outside where the dyneema passes into the boat?

Cool idea, I would try to waterproof from bottom, but there's no harm in trying to squeeze goop into the top as well. Something like this avoids metal fittings (except for machine screws):



Of course, if you're going this deep, you might also consider just making a fiberglass chain-plate, fully bonded into the hull, and attach your dyneema to that.

[stnick]

On your Smart phone a free app KNOTS 3 D . I use it to teach knots to new students.

[estarzinger]

The french have been DIYing these for about a decade on the G-class and such boats.

On those boats, in many areas they just dont worry about little deck leaks, so the just fill the thru deck tube of with silicone and leave the knot exposed underneath.

Where they want it watertight - it has always been a screw cap that I have seen. At the inexpensive end - pvc screw cap on a threaded pvc pipe which is neatly epoxied to the backing plate. On the more 'custom' end of things they profile and machine threads (or cast - this is often carbon at the high end) into the backing plate and screw a cap on that.

The flat cap screwed on in atmartin's would work, but would be heavier (I think) because the backing plate needs to be thicker.

It is real easy to machine plastic like delrin, and I imagine if you bought one ropeeye and dissembled it and took it to a machine shop, they could make you 10 pretty inexpensively. I have always wondered (dont know) if Ropeeye actually sources those parts and if you showed them to someone in the plastic fitting/plumbing world whether they could just get exactly the same wholesale for pennies.

[foufou]

If the load is close to parallel to the surface it is attached to then there is no need to drill through. I have made a hounds fitting on carbon masts that used a piece of fiber glass cloth rectangular in shape. I pulled the cross strands out LC the middle third. Twisted the middle third into a rope and wrapped it around a thimble. Epoxied the entire thing and applied the the two cloth thirds together onto the mast. . Don't know if the description is easy to understand. I can't do a drawing now. On a bus....but it has worked flawlessly for ten years

[waterman46]

OP didn't say how strong this fitting must be but mentions stress is nearly parallel to hull. For best strength no leak and simplicity just buy SS u-bolt, drill 2 holes in line with stress, add SS backing plate. A thimble could be captured between hull and u-bolt if required. SS U-bolt only about $4 at Home Depot, backing plate is scrap.

[Benz]

Mike, I did exactly what you're talking about, but didn't need the waterproofing. I just tied a diamond knot in a piece of Dyneema and pushed it through the FG tube I'd glassed. I suspect it's stronger than a ropeye, since that carbon button is holding all the strands with essentially glue.
My favorite ghetto waterproofing, which I think would be fine in your application, is toilet bowl sealing ring wax. Just pack the tube tight with it around the dyneema, and it will squish in. It's not like the dyneema moves around, once you have the stays tight.

[james247]

Originally Posted by mrybas

These seem like they would be fairly easy to make your own. I was thinking a piece of dyneema tied into a loop with a button knot. Pass this through a small as possible hole in a g10 backing plate.

The harder part would be keeping the fitting water tight. You could fill hole in the deck around the dyneema with sealant, but won't look great and probably leak a little bit. Any better ideas to waterproof the hole in the deck? Maybe a watertight electrical compression fitting?

Seriously how much are you saving.

[mrybas]

Originally Posted by james247

Seriously how much are you saving.

I️ think Rope Eye, Antal, etc charge $200-$300 for their version. Could be DIY for $40. If you had multiple over your deck, I️t would save thousands.

[valhalla360]

Originally Posted by waterman46

OP didn't say how strong this fitting must be but mentions stress is nearly parallel to hull. For best strength no leak and simplicity just buy SS u-bolt, drill 2 holes in line with stress, add SS backing plate. A thimble could be captured between hull and u-bolt if required. SS U-bolt only about $4 at Home Depot, backing plate is scrap.

I must not understand the purpose because something like this seems a lot simpler and more reliable.

[thinwater]

Originally Posted by atmartin

Cool idea, I would try to waterproof from bottom, but there's no harm in trying to squeeze goop into the top as well. Something like this avoids metal fittings (except for machine screws):



Of course, if you're going this deep, you might also consider just making a fiberglass chain-plate, fully bonded into the hull, and attach your dyneema to that.

I do like the idea. Yes, obviously an SS pad eye would be simple. But we don't learn much that way, do we? I will go out on a limb and say it is a VERY rare boat that would not be better off with low friction rings in place of blocks in a few applications, and that Dyneema is better than polyester for somethings even for cheap cruisers. But most like to stay with what they know.

You need to be 100% certain no water gets in the sealed area, because it will freeze and blow even bolted G10 apart. Ice will blow steel apart. The potting needs to be complete.

Once you get this worked out, is it really much harder to make than a pad eye? There is only one hole to seal instead of two. The G10 can be small bits and scraps, not much more than is needed with a pad eye. To get to uber high strength will require some more engineering and testing, but to get to a few thousand pound WLL should be doabale.