Preparing our Mizzen Mast for Dyneema rigging

Today it was time to start getting the mizzen mast prepared for the Dyneema Rigging.

FR4 Tangs

Jane got busy on carving the FR4 mast tangs. We need 8 (2 forestays, 2 cap shrouds, 2 lower shrouds, 2 running backstays). This was working with the basic “triangles” I cut the other day (see DIY Mast tangs for Dyneema:┬áprogress).

We did vacuum up the dust from the workmate and from the tarp as we went.

Between getting started, interruptions and recharging the dremel she managed nearly two completed tangs today. They are getting a bit quicker but it is going to need quite a few more days work!

Mizzen mast prep

Meanwhile, I started work on the mast itself.

There were some things we knew we needed to remove:

  • one remaining radar reflector bracket (the other has already broken off)
  • the radar mount (we no longer have radar, we would not trust a new radar to this mount!)
  • the deck light (we want LED and it was in poor condition)
  • a couple of plastic cleats (one of them broken). There are already 4 original alloy cleats and only potential for 4 lines at the mast head.
  • the VHF aerial (we need a new one for both VHF and AIS).

When we saw how much corrosion was under some of these (indicating that the different metals had not been electrically separated causing galvanic corrosion) we decided that this is our best opportunity to do a full refurbishment.

So as well as removing the deck light we also removed the external channel for it’s wire (that was riveted to the mast).

Having decided to do a full refurbishment I spent some time doing research. We have decided to go for a full epoxy paint. So we are removing anything that doesn’t look absolutely perfect. At the lower end of the mast the gooseneck, winch bases and original cleats are all looking good, plus they are low enough that they could be removed and refitted with the mast up.

Further up the mast the two higher shroud attachment points have stainless plates riveted to stop the through bolt elongating the hole. I was a bit concerned about some signs of corrosion, so I have removed them (and the VHF bracket). You can see the end of the compression tube in the bolt hole. In this picture you can see I have taken off the mast head, which also came off very easily (note that I have replaced the very bad halyards with messenger lines). I will add an extra line for an internal topping lift rather than use the external block that is shackled on).

Here you can see the lowest shroud attachment. No stainless steel plate for this one as there is not enough space above the hole due to the spreader attachment. Looks like some corrosion where whatever was used as a barrier between the stainless steel and the aluminium has failed.

Top of the mast with the mast head removed.


We are going with mostly International Paints Products. So 2 part epoxy Interprotect Primer (grey) followed by 2 part Perfection Undercoat (white) and then Perfection gloss top coat (Mediterranean White).

Before the primer we need to prepare the surface. So sanding (I’ve ordered a special ScotchBrite pad – we need to be careful not to use anything metallic when doing the surface work as it could cause more galvanic corrosion), the cleaning with acetone before applying the primer ASAP (the aluminium oxidises really quickly which stops the primer adhering properly).

After the Primer we will use thickened epoxy to fill all the holes that are no longer needed and make good any areas where we had to sand away pitting.

We are aiming for 2 coats primer, then 1 coat undercoat and 2 coats top coat. We have ordered enough paint for the main mast as well. So we will get that prepared to the same point and sand, and paint with primer together (then the rush is a bit over).

Once the painting is done we have a few more things to fit and so I have been sourcing some of these.

  • new bolts, washers and more to attach the tangs for the dyneema shrouds. The imperial measurement bolts won’t be ready until 8th September which delays putting the mizzen mast up. It took ages to sort out and calculate the bolt lengths as it is affected by the angle the shrouds meet the mast.
  • new VHF/AIS aerial (probably from Digital Yacht as we will probably use their AIS devices)
  • new deck/cockpit light (probably on the spreaders rather than the front of the mast so they light up the area for reefing the mizzen).

I have been looking up how to install wiring in a mast and avoid them rattling as the boat rolls. Seems the best way is to install electrical conduit and rivet it to the inside front of the mast. Not sure yet about this.

I also want to sort our lazy jacks for the mizzen to control the sail better when we lower it.

I have bought a rivet gun and (very expensive) Monel rivets (they are an inert metal which means no galvanic corrosion). I have also order Duralac which is used to insulate stainless steel from the aluminium.

At this point I’m in two minds about putting the mizzen mast up. It will be very handy for sorting the fit of the dyneema shrouds/chainplates; the solar panels; the pushpit and later the hydrovane. However, one of the beauties of the way we are fitting the dyneema shrouds is how easy it is to remove them from the mast when it isn’t up. If we don’t have the mast up all winter the boat will be quieter and there will be no wear or UV dammage on the shrouds or chainplates.

Anyway it is now raining and expected to rain all day on Tuesday, so back to inside jobs in the morning.

Testing our Rib with ePropulsion electric motor

I’ve been for the first test ride in our Highfield Classic 290 Rib with the ePropulsion electric motor.

Now just drifting upto the beach with the tide. Being lazy and reducing the distance to pull the dinghy up.

I recorded some of the ride on Strava the electric motor makes it so easy.

Anyway, comfy, dry and much faster than walking ­čśŹ

Starboard side of saloon progress

Following the first stage of clearing the starboard side of the saloon we got stuck into a whole lot of progress.

We had a number of objectives. We wanted to remove the soffit to make fitting the new chainplate backing plates easier. We wanted to get it all cleaned (quite a bit of mould and the hull was quite sticky). We also wanted to make progress on the planks that will be dual purpose. In day mode they will be used for the backrest. In sea berth mode they will be used to stop you being thrown out of the bunk. We also realised that just putting the lowest board in will make the bed more comfortable even when not at sea by holding the cushions in tight.

After removing the soffit and doing the cleaning

Preparing the planks by routing the edges and sanding.

Then building channels to drop the planks into when they are used as Lee Boards at sea.

This is in sleep mode when not on passage. It keeps the join between the two cushions nice and tight so it is more comfortable than it was. I’ll drop the height stops a little so that we can leave this lowest plank in all the time. Even when used as a settee.

This is in full Lee Board mode for sleeping at sea. The top 3 boards will have padding added which will make them more comfortable both as Lee Boards and as the back rest.

Obviously still work to do.

As an interim measure (as we have a guest coming) we are going to paint the hull and underside of the deck.

I’m going to lower the stops a little so that the bottom plank becomes an almost permanent fixture.

Then sort out channels so that the other 3 planks can be used as the back rest. Jane will then sort out the padding for them.

At some point we will need to have a storage place for those 3 planks when sleeping ashore or at anchor (probably against the side of the hull).

When in full Lee Board mode, the planks are a bit too flexible. So we are exploring options to stop them bending too much in the middle. One idea is to have a vertical pole handhold that we can fix in place when sailing. It would be right up up against the middle of the boards so they couldn’t bend outwards at all. It is a very useful place for an extra handhold when moving forwards.

I’ll also need a brace of some kind to stop the boards bending too much when used as back rests. Still thinking about that.

Bow roller test fit

Very conveniently, on the first morning of our summer holiday, we had a call from Anglesey Fabrications to say that our modified bow roller was ready for a test fitting.

Very close. Just a slight adjustment to the cutout of the tails so it drops fully onto the hull. Then a bottom plate to join the two side extensions. Finally a lot of polishing.

Then we can fit it (will require some fibreglass work to the deck). Once we have tested it with the anchor we can sort our the roller and the cross bars (used to contain the anchor and stop it damaging the rigging).

Very happy so far. Testing with the anchor is obviously a significant step still to come.

DIY Mast tangs for Dyneema: progress

I’ve done the first basic cut out of all our tangs. They are made from FR4.

The 6 bottom left are for the mizzen shrouds. The 2 top left are for the mizzen running backstays.

The 6 bottom right are for the main shrouds on the main mast. The top right are for the main mast backstays.

I haven’t had time to sort out the tangs that will be for the new inner forestay and it’s support shrouds.

Dinghy launching wheels

So our dinghy is a Highfield Classic 290, an aluminium (for long life, light weight and fully recyclable) hull with Hypalon Tubes (much longer lasting than PVC, especially in the tropics). Jane has already made a fantastic all over cover for it (when it is stored right way up) and it sits at home on a little cradle I made.

We chose our dinghy as the largest that we could fit inside our van, that happens to also be the largest we can fit on our foredeck. We chose that size as we expect to have four summers of using it in the Menai Strait (where due to the tide speed and the funnelling of the wind you get quite big waves), including transporting everything we will own onto the boat when we become retired live aboard cruisers. It also has a false floor which means that even if some spray or rain comes in your feet and bags do not rest in a puddle.

However, the key disadvantage is that it weighs more, just under 60kg. So we don’t want to carry it up a beach or slipway and despite it being Aluminium we don’t want to drag it much either (especially on stones or concrete).

So we have bought some launching wheels that can fold and that can also be removed. These were at the budget end of the market so we will see how well they last. They did need some “adjusting” with a Dremel for them to latch properly in the down position. I also had to add some pads to space them from the transom so that they don’t touch the lip of the hull. Unfortunately the lifting points on the transom stop them fully folding but we can hold them up out of the water with an elastic bungy which should be perfectly satisfactory.

It is easy, on my own, to attach them and get them into the down position as well as to remove them. The dinghy is easy to move by myself when it is on the wheels (although I don’t think we will be loading it up with much stuff at that point).

Altogether pretty happy ­čÖé We will be taking it to test during our summer holiday.

Heavy weather sailing tick box exercise

So I’ve just added the classic “Heavy Weather Sailing” 7th edition by Peter Bruce to our library.

Very interested to note how well our choices fit with the various chapters:

Chapter 1 on boat design could have taken the Rival range (although never mentioned) as a model. So we see the great designer Olin Stephens recommending:

  • balanced hull shape (Tick)
  • low freeboard (Tick)
  • small well drained cockpit (Tick)
  • two masts (Tick)
  • not too wide (Tick)
  • deeper rather than shallow hulls (Tick)
  • higher cabin sides (Tick)
  • strong keel (Tick)

In Chapter 2 on stability in breaking waves by Andrew Claughton we also tick lots of boxes

  • Our keel being a fairly long fin with a good skeg
  • balanced ends
  • lower freeboard with high coachroof
  • everything we see implies a Rival 38 should have a pretty good stability curve, we have heard that Peter Brett was very aware of the angle of vanishing stability (a point where the boat no longer tries to turn the right way up after being knocked over)
  • There is a table summarising the design influences on capsize and a Rival is pretty much solidly in the safer spectrum for them all.

The Jordan Series drogue gets it’s first mention, and they are all positive.

Chapter 3 on design trends by Peter Bruce

This puts the Rival in what seems to us to be a sweet spot after the development of fin keels but before dish shaped boats with small fins and spade rudders. This is a sweet spot for short handed cruising as faster, more modern designs tend to need to follow more active tactics. We are not going to have experienced racing dinghy sailors or surfers who can actively surf down huge waves safely so better have a design that doesn’t favour such tactics.

This is the first chapter to note the negative impact of roller furling sails on a boats stability (due to the extra weight up high when the sail is furled). That is one of the features of our desired long-term sail plan.

There is a concise but comprehensive list of questionable design features and we seem to be clear of them all (except I think we might want to strengthen our cockpit locker and we already know we need a way of securing our hatch boards). All the work to remove seacocks and only have composite ones fits too (although that post is now a bit out of date, with the electric motor we have only 2 seacocks below the waterline which are the e cockpit drains, we won’t have holes for the fridge or depth sounder and the 2 seacocks will be protected by a coffer dam so that a failure won’t cause us to sink).

Chapter 4 on Spars and rigging by Matthew Sheaham and Harry James

One point is the expectation that composite rigging such as Dyneema will one day be used universally with the weight reduction being a very significant gain for stability.

Another is more concerns about the weight of roller furled sails and the dangers of a failure. With slab reefing there are concerns about friction for systems brought back to the cockpit (ours are not).

Chapter 5 on Storm Sails by Peter Bruce and Richard Clifford.

Here we score well for plans although we haven’t got as far as implementing them. So adding our inner forestay to be used for either a staysail or a storm job is good.

We haven’t got as far as thinking much about practicalities for a trysail. We don’t currently have a track, a sail or anything. With a mizzen that can be reefed we do have an alternative so it isn’t quite as urgent.

Chapter 6 on preparations for heavy weather is mostly for the future but it does reinforce the desire for a Hydrovane. The section on fires adds weight to my plan to fit fuses at the battery terminals and to make sure the battery boxes are watertight. Having no fossil fuels aboard is clearly a significant safety feature.

Chapter 7 on the use of drag devices has clearly been updated with details on the Jordan Series drogue which are very positive with the only downside being the difficulty of recovery until conditions have moderated significantly. So nice to see our thinking reinforced.

That is all I have read fully so far, I can see from the “Storm Experiences” section that we are going to feel good about not having davits for our dinghy – but we think that is pretty obvious. We know we have a lot of experience of actual heavy weather that we need to build. However, I am reassured that much of our thinking is already validated by this highly respected book.

Electric Motor one thing that is not covered at all is having an electric motor. There is quite a lot on the advantages of a reliable diesel, but with the recognition that there can be significant problems (lines around the propeller after a rigging failure, flooding through the exhaust or engine room ventilation, extreme angles of heel causing problems, dirty fuel especially with sediment from the tanks. We have to make our plans with the assumption that we will not be able to use the electric motor for long enough to make it a viable tactic for anything but manoeuvring assistance. As we have written before we think this is better than an over dependence on a diesel, in particular a false sense of security that it will always work see Another example of why to switch away from Diesel and Losing a diesel engine for safety

Mast tang for dyneema shroud progress

Today I started on the tangs for the mizzen mast.

This has 9mm Dyneema shrouds. So I have an 18mm sheet of FR4. This means I can have sides tall enough to put a retainer between them to stop the shroud jumping out.

This first one is 80mm wide, tapering to 30mm and is 100mm high. I think I’ll make the next ones a little wider still.

I don’t have the dremel with me at home so this is just the initial shaping with the Jigsaw, then using the drill press to put a 10mm hole through and a hacksaw to open the top a bit.

Using the dremel and a sander I should be able to get it all nice and rounded and smooth.

Then an angled hole for the through mast bolt so that this sits at the correct angle for the shroud. Possibly a stainless steel bushing and possibly some thickened epoxy on the sides so that they sit correctly against the mast and the bolt head (or nut).

One thing is clear. I’m going to think about creating some jigs to guide the tools.

Still reasonably happy. 8 of these needed for the mizzen.

See my post Dyneema / Synthetic Rigging Summary to see the big picture of how this all fits together.