Naiad's mainsail is bent onto the mast using individual grommets that have plastic parrel beads threaded onto the line and while this works most of the time, the fact that the grommet, being made from rope, is flexible, means that there are occasions when the grommets jam when raising or lowering the sail, even with the parrel beads.

My intention originally was to use wooden mast hoops, but I put on the various hounds and mast bands and bedded them down securely forgetting to buy and install the hoops first, hence the use of the grommets.

However, I have found that you can get replaceable mast hoops that have bolts instead of being riveted. With a 100mm or 4" diameter mast I needed 125mm or 5" hoops but as a check I made a 5" internal diameter hoop from plywood to see how far the hoop would go on the mast.

A CNC router is a very useful tool. The plywood hoop took less than 30 minutes to make.

This is as far as the plywood hoop will go, the hounds for the shrouds are too wide to allow it to go any further. So I ordered four of the replaceable hoops from Australia.

They arrived very quickly and look really nice.

Here I have removed the end screw and the three bronze bolts and there is very little spring back as you can see.

A closer look shows that the hoop has opened up slightly with the outer end moving back between 10 and 15mm.

The hoop passed over the truck easily.

And the top mast band even with one block still attached.

The upper hounds were passed as was the mounting block for the AIS aerial, but not the hounds for the shrouds as expected.

To get over the hounds the hoop needs to be wound past the obstruction.

Almost there.

And done. For the first part anyway. I may have been able to open the hoop wide enough to fit over the hounds but winding it around spirally doesn't open the hoop as much and thus there is less strain on the hoop, which is a good thing.  

The same procedure is followed for the lower mast hoop.

Until the hoop is past the obstructions and now on the part of the mast where it belongs. You'll notice that the hoop has opened up a little more as the holes are now about 20mm apart.

Even so, it was not difficult to tighten the hoop such that the bolts could be fitted as you can see here. You can also see the end screw that stops the outer end of the hoop from lifting up.

The bolts will be take out one by one, cut to length and refitted with a little thread lock to secure the nuts.

This looks nice and I'm pleased that I've finally done it.

However, it's not warm outside today (for England, that is) and my hands are very cold, so...

Time for a cup of tea.