Sunday 24 March 2024

Overdue Cosmetics ... ?

 


The companionway steps have been pretty manky for a long time. I took them home to get them sanded and re-varnished - Angus did the work, and substantially exceeded expectations.

The piece of mahogany on top of the table saw bench is a new lid for the stern cockpit locker. The piece on the floor to the right is the 'shelf' I put at the front of the cockpit (like a bridge deck) to create a space for putting things down and under. I think there is a photo of it somewhere in this blog...

Both pieces of mahogany came from the counter in my grandfather's photography shop (now long gone), so definitely recycled. I may get one or two other useful sections out of it, although it has some damage and quite a bit of surface 'patina'. If it was perfect it would just look wrong on Raasay, in any case.


Saturday 24 February 2024

 



So - I have installed new batteries.

I was up a few days ago, and the mains battery charger started behaving oddly when I switched it on. After a brief investigation, I discovered that the batteries had lost a lot of electrolyte. The tops of the plates were clearly exposed.

I topped them up and tried charging them again. This didn't work. There may be more extreme resuscitation methods I could try, but the original batteries were already a long way through their useful life and I didn't fancy having to rely on semi-dodgy batteries...

I had also been thinking about switching from conventional lead acid to AGM, so this seemed a good time to do it.

I don't really know why the electrolyte was low. I check it fairly regularly. I normally switch the charger off when I'm not on the boat, but did leave it switched on for a couple of weeks by accident recently. I find it hard to believe this was relevant, as I used to leave the charger switched on permanently - up until two or three years ago, when I learned that this might not be a good idea.

The charger is a 25 amp NOCO Genius charger, which should be safe enough to leave permanently on ...

The drop in the electrolyte level did look like the consequence of a boiling event, though.

Anyhow, I now have AGMs. So I don't have to worry about heel angles anymore. Or about topping up.

A small issue:

The Leoch AGMs are rated as '115 ah', and the Trojan batteries I removed are rated at '225 ah'. However, both are rated at 115 ah (or thereabouts) for a ten-hour discharge period. The higher rate for the Trojans is for a twenty-hour discharge. The arithmetic here doesn't quite make sense, because 10 amps over 10 hours is 100 ah, and over 20 hours is 200 ah... I'll need to go back through the specs to understand this.

I should still be able to discharge 10 amps for 10 hours and keep the bank (two batteries) about 50% charge. This looks fine for overnight sailing, for instance.

I have a Sterling Alternator to Battery charger capable of putting 90 amps (alternator maximum) into the batteries during the boost phase of the charge.

I also have a 200w solar panel to deal with lower demands.





Friday 24 November 2023

Friday 27 October 2023

Nearly Ready ...

With the (slightly wavery) boot top applied, and the topsides cleaned up, we're nearly ready to go:


There is one job left, that can only be done when the boat is lifted. The bottom of the keel needs cleaned up and CopperCoated. Lossiemouth Marina will put me in the boat lift the day before I launch, so I can do it then. I'll drape the bottom of the keel in Visqueen (a mini-tent ...) and heat the area up so that the CC cures quickly. I routinely dry the boat out (one reason for going for CopperCoat - it can be maintained alongside), so I expect the bottom of the keel to get a good bit of wear. And it's rarely seen.

I guess I'm saying it may end up a bit rough.

But I don't know how else I could do it ...

Replacing the Rudder and Prop

I thought I had the prop shaft installation finished until I made this unpleasant discovery:


The new prop shaft isn't shorter - I'd just inserted it further into the clamp than the old one had been. Undoing the clamp again was a grim prospect, but I'm getting quite good at it now & have all the right equipment.

Here's the rudder having CopperCoat applied:




And here's everything reassembled again:


Five minutes to post about three days work ...



The Stuffing Box Hose

 


This was very difficult to remove and replace. It goes from the stern tube to the stuffing box, and it's underneath the fuel tank, partly behind a small bulkhead.

The hose clamps on the aft end (that secure it to the stern tube) are particularly difficult to get at (very long extensions on the 1/4" drive ...)

Here is the new one :



And here it is in place, with the new prop shaft:



I cleaned up the stuffing box, replaced the grease injection joint with a stainless steel connector, and renewed the stuffing.

This is the area I am most worried about when the boat goes back in. It's even harder to access now than it looks in this picture because the exhaust system is back in place.

Here's what it looked like before:


And yes, the dimensions are slightly different. The new hose is an inch longer. I wanted to see it better...

Finally - some useful tools:



CopperCoating The Hull

Here's the Visqueen tent we set up to create a warmer (12-14 degrees) environment.


This worked extremely well, although there were some diesel fumes ... I had a CO meter inside it. It stayed resolutely at zero.

Applying the CopperCoat was a fraught business. We started about mid-day and finished about midnight. And then had to stay up a lot of the night to monitor the diesel heater as the outside temperature was expected to drop below 8 degrees ...

We just kept adding coats until we'd used up 7 of the 8 'doses'. One was kept back to do the shoe of the keel and the rudder. We also saved a bit by stopping at the waterline rather than using it as a boot top as well. We definitely got four coats on everywhere and possibly five - certainly over large areas of the hull.

The first coat was epoxy only (no copper powder), and it was a bit thick in a few small patches. We ended up with drips ...

After that, we thinned the mix and rolled it on carefully - spreading it out as much as we could.


It set up overnight and was completely hard and dry after a day or two.



Wednesday 4 October 2023

Prop Shaft Removal

After my struggles with the Allen bolts in the prop shaft clamp a year or two ago, I wasn't looking forward to this. At the time I gave them a good soak in WD40, and this seems to have penetrated - I got them out fairly easily this time.

I didn't realise that there were also two grub screws in one side of the clamp until a friend specualated that there might be ... they were pretty well disguised with rust and dirt.

I opened the clamp using a couple of chisels which I cut down and modified for the job:



The biggest problem, in the end, was dealing with the key in the shaft at the inboard end. This was made of stainless steel, and I couldn't get it out. Access is very difficult.

In the end, I had to grind it off - this was scary and took a lot of preparation (wooden blocks, a hose to wet things down, a handy fire extinguisher...).

Once I removed the Cutless bearing, I could draw the shaft past the skeg on the starboard side. It was a bit of a squeeze.


The engine and shaft are slightly swung to starboard to make this possible. Otherwise, the engine would have to come out to draw the shaft.

I was disappointed to find that my (fairly new) Cutless bearing was quite worn and that the shaft was also worn in the same area. Somehow, the water wasn't getting into the bearing?

This will need some thought. I'm getting a new shaft made - I'm worried about the pitting I saw earlier, and also now by the wear.

Rudder removal

This was, slightly unexpectedly, a stinker of a job.








I thought the shoe on the bottom of the skeg would present difficulties, but the silicon bolts actually came out readily, and the shoe was easy to remove.


The rudder head, however, was a different issue. I've come to the conclusion that this could only have been fitted by heating up the bronze casting (very considerably) and then pressing it onto the shaft. It was extremely difficult to get off, and I ended up damaging the thread and the nut with a sledgehammer.




Once I had got it to move slightly I could get a puller under it. With a lot of heat, this finally got it out. I now have a bit of an engineering challenge repairing the thread and replacing the nut:



A man is coming to look at it on Friday ... 

I can think of a few solutions. None of them will be cheap.

I also have the problem of getting the bronze rudder head fitting back onto the shaft. I will get advice on this. It might be worth getting it very slightly reamed. The rudder actually hangs by this fitting - the bottom of the stock is located in the skeg shoe, but it doesn't rest on it.

And, as it happens, all the bearings look fine ...

The rudder needed to come out for another reason, which was to allow clear access to the skeg for copper-coating:

Knowing what I know now, I might have passed on this ...


Coppercoat Preparation

 


We used Peelaway Marine to strip the existing antifouling. It took two tubs, and we could probably have done with using a third ... It's quite expensive, but a lot cheaper than many days of scraping and sanding. Some of the first layer of AF (the black) didn't entirely come off, but scraped down fairly easily.

Under the antifouling we found a layer that we are reasonably confident (!) is a two part epoxy primer applied on top of the old coppercoat. Coppercoat reckons this is a good base.


There was still a good deal of sanding to do to prepare the surface - 80 grit, and about four days work.

If we've got all the nooks and crannies done by this weekend, the next step will be to skirt the hull and use a big diesel heater to warm it up ...


Overdue Cosmetics ... ?

  The companionway steps have been pretty manky for a long time. I took them home to get them sanded and re-varnished - Angus did the work, ...