4th June

Been busy with non boating things over the last couple of days but did manage to collect the "eyes".

Now Nuts is happy and can see where it is going.

Fired up my tractor this evening and did some pulling tests.

Was an interesting exercise.   

I epoxied 3mm dyneema into 20mm deep holes of different diameters and different epoxy mixes and at different angles (straight and 45 degrees) and pulled them apart whilst measuring the kg force.

Results:

Both ends in single 7mm hole with thickened epoxy.  Pulled out at 80kg.  Easy but not good.

2 loops glued into 5mm holes ( one with vertical holes and the other with 45 degrees angle) with unthickened epoxy.  Dipped the ends first to let capillary action draw some epoxy into the fibers and pushed the ends into holes filled with neat epoxy resin.  Was a bit messy and would not work on a vertical surface.  Also not easy to get the rope end to go into the hole as it opens up.  Did pretty well on the pull test  - 216kg on the straight drilled holes and 260kg on the angled holes.

Last test was 6mm holes also straight and angled but using thickened epoxy so it does not run out the hole on a vertical surface.  Gave the rope ends a swirl in the mix and pushed them into the epoxy filled holes (using a small nail to get the strands in).  Results - straight holes 330kg and the angled pull 220kg.  The angled pull pulled out a piece of the wood.

After these test I decided to compare with stainless steel saddles screwed into the same piece of wood.

I tried two different types of saddles.  Used the same 20mm by4mm screws for both without drilling pilot holes.

What they looked like after being pulled out.  They were not easy to find as when they pull out it goes with a BANG.  Stamped sheet saddle on the left went at 281kg and the cast? saddle pulled out at 288kg.  The cast one looks like new but the other is scrap.  I was amazed at how much pressure can be put on 2 small 20mm screws in pine pulling directly out and not in a sheer direction.

So -  Conclusion - Stainless saddles screwed into pine are pretty strong, clean and quick.  Using Dyneema to make glued in saddles also works and would go with 6mm holes (using 3mm dyneema) with thickened epoxy resin and maybe neat resin dip to fill rope ends.  The 6mm holes were also the easiest to use.  This is the cheapest and lightest option.  I would only use these systems for tie down points inside the boat to keep things in place. Especially if you want to use a small ratchet strap for things like a battery or  anchor storage as you can make the hold down saddle strap whatever size you like.. Through bolts on backing pads with big washers for anything safety related on deck though.

Trimtab fittings got a small polish and tab filled, sanded and epoxy primed.  Now just got to mount the flying bridge and helipad.😃