Saturday, December 21, 2019

The heat was on there for a while. Too much of it in the wrong place.

Its been far too long since the last time I had Kairos out of the water for a scrub and antifouling, so she had quite the oyster and barnacle farm under there.  The silt laden and often brackish water here in the upper reaches of the estuary seem to encourage them.
I’d noted that Henry the Ford diesel was smelling a bit hot, so had searched out a new sensor and gauge,and when Steff the amiable and helpful 12 volt wizard from North Harbour Auto, air and electrical  (highly recommended, we get our cars serviced there as well as the sparky stuff done  ) was here looking at some problems the original wiring in this old ship was causing, he fitted those so I’d know just how hot Henry was getting under the cabin floor there.

It was time I scrubbed the bottom, we’re expecting to go cruising this summer, Denny and I, events have overtaken our budget so we’re staying around home.  But a week or so away on the boat is a pretty good substitute so I figured that I’d best be ready.

Off down the river to the scrubbing grid, and Henry wasn’t happy, no piddle out of the water circulation indicator.  I thought that the growth on the bottom was such that the water inlet was blocked, so shut the engine down and drifted with the tide and wind helping me, only starting the engine when I needed to thread my way through the moorings.

I was quite proud of the way I maneuvered Kairos, all 43 ft and near 15 tons of her into the cramped space on the grid, tide and wind pushing her around,  got it first try, got a couple of lines around the piles and shut a boiling Henry off again.

Over the next two tides ( one was around midnight ) I got the bottom scraped off pretty clean, and removed the barnacles from the bronze prop and rudder, those would be the reason she was hard to steer, and did a very careful job of cleaning the through hull fittings.
I even pulled the ball valve and associated hosing off the inside of the engine water inlet to check that no bivalve had taken up residence in there. All clear.
I even checked the manual to see if the cooling pump needed priming. ( no)

There were other jobs to do, I repositioned all three bilge pumps, having replaced two quite recently, got their switches working properly, cleaned out the empty hose from the head holding tank which had a variety of shellfish living therein, ( didn’t save those for a snack) and a few other things.

But when it came time to head on out, at about an hour before high tide, remembering that once the tide fell a little I’d be there for another tide. I fired Henry up, and checked.  Still no piddle.  I thought of the  words on the cover of the Hitch hikers guide to the Universe, and said to myself, “Don’t panic”.

Tore the floorboards up, checked all the water lines, all ok, the only thing left was the water pump.  Now, while I know how they work in theory, and had watched a YouTube video on replacing the impeller in a pump like this, I’d never done it before.
Kairos had two spare impellers in her spares locker plus a complete new pump.  Try the easy option first, out with the toolkit, down in the engine bay, very hot down there, grab the spotlight so I could see, hotter still.  Did the contortionist thing that any work on that engine seems to require, and pulled the back plate off the pump.
A mass of mangled rubber fell out.  That might have been an impeller sometime, but not any more.

With the tide now falling, I think I set a world record for a first timer fitting a new impeller to one of these pumps, got more than a few bruises from leaning on the sharp bits on the engine, and was getting a bit faint from the heat when I came up to turn the key to see if that worked.
It took a couple of minutes, but then the water stream was clear and steady.  Phew!
Drank a mugful of water to ward off dehydration, cast off and headed out, leaving the bow line on so the fast running incoming tide could swing the ship to face the way out, let that line go and away.

It takes a bit over half an hour to get upstream to my berth, and it was great to have Kairos handling well again, responsive, quieter, and the temperature gauge was sitting on about 50C, coolish, but a lot better than 120C and pushing steam out the pressure cap.

Several jobs well done.  She’s coming out of the water for a full paint job, probably in March sometime. Scrape the hull bare, new paint from the wood out, the stuff that’s there is 49 years old and although its had paint over it, its flaking off in places so its time for a major.

In the meantime, Henry is a lot happier.

The remains of the 3inch diameter Jabsco engine cooling pump impeller.  And a mug of tea. very welcome that mug of tea was.

Wednesday, December 18, 2019

Small comforts.

Comfort, and I think I’ve said this before, can be a whole lot of small things that add up to an elimination of all the annoying things that just don’t fit.

Kairos helm seat is quite high, it leaves the legs dangling about a foot ( or two feet  if I were being funny about it)  above the cabin sole, so for the most part a voyage is spent standing up with one hand on the wheel and one on the dashboard.
Lower the seat? I thought about that, very briefly, when its down a bit its not possible to see over the bow when sitting so thats out.
Standing  there is tiring after a while, the little plastic kitchen stool that I plucked out of the river on one of my rubbish collection rows isn’t high enough to make an effective footrest, and I got annoyed enough the other day to do something about it.
I’d been annoyed about this before, but sometimes the circumstances have to align in order that things can happen.
So, I had offcuts of heavy plywood from another job, a rainy day on which that I couldn’t do the job I had planned for that day, and some test running of “Old Henry” the big Ford diesel which meant sitting at the controls for a while.

Got started. Made a cardboard and hot glue mockup, tested for height and angle, and fit. The shape there is a combination of  a slight slope of the bulkhead forward of the footrest box, a curve in the side of the cabin plus it slopes down from forward to aft, yet another angle where it meets the front of the side seats, and the cabin sole has a very slight slope in still another direction .
House builders have it easy, almost everything is straight and square. 

So, I’ve built it. It has a removable top, and yes its secure so wont slide around, and the “box” will be used as a home for emergency signal flares and the first aid kit.  I’ve got a coat of varnish on it now, ( not shown in the pics), have a piece of carpet cut to fit the little space behind it and am about to put a patch of non skid on the top to finish it off.

Another small improvement. Tick that box! 

Sunday, December 8, 2019

Preparing to go cruising.

Planning to go cruising is one thing, getting ready to go is another. The electrical system in this old ship of mine is now 47 years old and pretty near everything in her is electric. The original wiring is domestic rather than tinned marine grade, and over the past 12 months or so I've been gradually losing one function after another. Very annoying, but the public swimming pools down the road have showers for two bucks, and sponge baths are ok for a day or two. I've not been out in her much so the nav lights not working werent an issue, but when the heads pump stopped working that was just too much. So Steff from North Shore Auto Electrical was called in, and spent much of the day here to day. I'd put new house batteries in last Friday, the old ones were very dead and only useful for holding bits of wood together until the glue set (26 kg each, thats 57 anna bit pounds) so out they came. Carrying one of those in each hand flattens the arches of the feet a little, but the two new ones ( flattened the wallet a bit too) went in so they're good for half a decade or so. Glad to have that done.
I replaced two of the three water pumps, got the LPG water heater running again, fixed the blocked drain from the heads handbasin, and cleared the water intake for the head. But electrics are not really in my skill base, and the system in this old ship looks like a real rats nest.
So Steff was here for most of the afternoon, replaced quite a few bits of wiring, put fuses in where none had been before, re routed some circuits and changes some of the switches around. It all works now, he even installed the new engine temperature gauge and sensor, so now I can tell when old Henry the Ford diesel is getting too hot. Wonderful.
So all thats done. Just got to haul her out and do the antifouling, replace the anodes and clean the prop off and we're away. If I say that all quickly it doesn't sound like much, but there is over a grands worth of paint to prep for and apply.

I'm going to need that cruise to recover.

Saturday, December 7, 2019

Repair work

I’ve a boat in for repair.  Not my usual thing, but in this case the customer wants his boat ready to go for the nearly upon us summer holiday season, and “boat yards” aren't into doing small repairs on small sailing boats. Particularly not at this time of year when they’re under pressure to get their main customers boats out and on the water before their staff head away for the Christmas break.
So I agreed that I’d do it.
The boat in question is a Navigator, very nicely built by Peter Murton of Murtons Timbercraft in Nelson, and Indiver Nagpal, new to sailing  had a little misfortune sailing solo in her,  and I’m now spot painting the dings and scratches, and replacing broken gaff jaws.

Here’s some pics.

Maya, a Navigator from my drawing board and Peter Murtons capable hands, really nicely done. In a couple of days she'll be back out on the water with all her little wounds healed.  Here's a link to the builder who's just started on another JW boat, this one a Pathfinder.  I think he's getting close to 20 of my boats built and sent out to happy owners, wow!

Gaff jaws, the old ones were plenty strong, but the rig got tangled up with something tough and broke one side of the jaws off the spar. The replacements are carved from a Kowhai tree crook rather than laminated, now that the glue has set I can varnish then leather them. 

Sunday, November 10, 2019

We went sailing last weekend.

Its springtime here, the temperatures at night are still a bit chilly, especially up on the mountain lakes but the daytimes are lovely.  We had great weather, the sailing ranged from drifting conditions to really gusty, and as often the case on a lake with high hills and mountains around, the wind can vary in strength and direction in seconds. Challenging but fun.

Lake Tarawera is a volcanic lake roughly in the middle of our North Island, the result of a depression along a major geological fault line, has many hot spots, streams that run anything from lukewarm to hot enough to cook food in. Mt Doom, that’s mount Tarawera last erupted in 1886  which in vulcanology terms is very recent and the area is rated as “active”.

The lake is lovely, its in hilly country and is surrounded for the most part by forest,  the few houses are along a short str
ip of coast on the north side, and there are a number of well set up boat ramps and carparks which make launching and hauling our boats out easy and convenient.

Last weekend a group of us met there, sailed, camped, some tenting ashore and some sleeping on board.  We soaked in hot pools, swam in the lake, walked the bush tracks and otherwise just hung out with friends.
It was a great weekend, I’m planning to go back sometime soon.

For lots of pics, check out the Dinghy Cruising NZ facebook page, it’s a public page so you don’t have to sign up to view it.

In the meantime, here’s a pic of me out in Spook, her new mainsail setting nicely, it’s a little bigger than her old one, and that was a mighty big sail, but Spook carries the new one well. Thanks Dennis Conway for all the effort that went into designing and making it.

Sunday, October 20, 2019

I get questions about making a hollow mast, so here's how I go about it.

Mast making. Reinforcing an aluminium tube spar with a birdmouth inner plus solid blocking.

I’ve been given a mast blank,  a 5m long x 75, od, 5mm wall thickness chunk of T6 temper aluminium tube.  It was bought to be the main mast for a Pathfinder, but life got in the way of the builder completing the project and he very generously donated it to my cause.  (Thanks so much Brian,  very much appreciated)

It’s a little light for the unstayed rig on the longer, but slimmer, water ballasted Long Steps, so I’m reinforcing it through the mast step area and up to where the boom of the balanced lug main will be by making a hollow wooden tube that is a close fit inside, that takes care of the worst of the bending stresses where it passes through the top step in the roof of the “cabin”.
Its also a little bit short, so I need to make a wooden plug  to extend the top end of it, and while at it will put a tapered section on to get the halyard well above the yard and to fly the wind direction arrow up out of the turbulence of the mainsail.
Besides, it looks nice.

There has been a little discussion on my facebook group about birdsmouth spars, so, here’s an opportunity to show a step by step “how to”.

The reinforcing plug at the lower end is 1600 mm long, sized to fit inside the aly tube, and 250mm of it extends out the lower end to help give the spar a bit more length.  That section needs to be the same diameter as the outside of the aly tube, 75mm instead of the inside being 65mm.

Step one, off to Duckworksmagazine archives, and look up the birdsmouth spar calculator,

I wanted to have some spare thickness, especially in the lower piece so where I’d brought the diameter down to the ID of the aly tube, I’d still have enough to make a good contribution to the stiffness of the spar through that area, so went for a stave thickness of 22mm, that for the top and the bottom pieces.
It coincided with the thickness of a stack of planks I had, as with the length, they were pretty much made for the job at 140 x 22mm x 1600 long, or should I say the job was made for the materials available at the time.

I use 8 sides in most of my birdsmouth spars, I’ve a very good sawbench, (MBS 250, 3 hp,  good machine, often have other brands names on them) so I design my work around that.
Staves were 32mm x 22 mm, with a 45/45 deg vee in one edge, and that, with 16 staves took me a while to first straighten one of the rough sawn edges, poke the planks through the planer, then the other side to get them to the correct thickness then back to the sawbench to rip the planks into staves at the required width.

Next, set the saw blade over at 45 deg, run some scrap to get the blade height and the fence set right, and slide the staves through, one side, then swap ends and do the other side.  Nice little triangular pieces of waste and a lot of sawdust.

Some people will run these vee shapes with a router in a table, but as you can see, a sawbench with a good fence and a sharp blade does a perfectly adequate job, and much quicker.

Once done, being that these planks had been outside under very indifferent cover for two years, I stacked them with fillets ( stickers in US terminology) between the layers to help air circulation and left them for a week to get rid of excess moisture.
I don’t know for sure, but I think that these planks are American Southern Yellow Pine, they arrived here in NZ disguised as a shipping pallet. I was pleased to have them.  ( Thanks Bill)  The wood is fairly light weight, but tough and strong, glues well, is a bit tetchy to plane if you hit a knot or some reverse grain, but a very sharp plane handles it pretty well.

I tested the moisture content using the “match” test.  That’s a goodie if you don’t have a moisture meter.
Goes like so.  Put half a dozen matches along the plank, heads in contact with the wood, in the shade.  Wait overnight, and if in the morning, you can strike them and get a light, the moisture content is low enough to glue.
Any dampness, and the matches wont light.

Having made up all the staves, the assembly jig was next.  That’s simply a slightly oversize half circle cutout in a plywood scrap at each end of a support, like so. The cutout in this case was 80mm, it needs to be just a bit oversize to accommodate the way the staves fit together.

In the lower end of the lower section, there is a hardwood “blocking”.  That’s a solid piece that takes up all the space inside, in this case its 550mm long, cut square to the size of the inside space across opposing flats, then cut at 45deg on each corner to make eight equal sides.
That piece is Australian Jarrah, seriously hard wood, very strong, glues well.

Same with the top end, the hollow section needs “blocking” through the area where it sits into the aly tube, and a bit above where the halyard blocks are to be bolted in.  That piece is spruce, and you can see in the pic where I’ve cut away  the top end to reduce the “stress riser” where the section changes.

To explain that, a sudden change in the strength of a tube, or a beam or whatever, from one strength to another , in this case where the internal reinforcing suddenly stops, causes a much weaker area than either of the strengths each side of it.  Its know in engineering terms as a “stress riser” and that odd shape that you can see in the pic is a good way of ameliorating that problem.

Now, its about time to lay the spar up.

This procedure is the same whether it’s a short item as these are, or a full sized mast for a much larger boat, or anything in between.

I’ve made up shock cord lashings, pieces of car tyre inner tube with toggles, or suchlike will do.  Use lots. Have them ready to hand before you mix the glue.

I had at this stage tried a dry layup to check that the jig was right, lined 8 of the staves up ready  and it was time to get on with it.
Mix the glue, not so much thickener in this, it needs to be brushable, almost a syrup consistency rather than the peanut butter thixotrope that we usually mix with our epoxy glues.
Brush the glue in, in this case it was 5 pumps each of hardener and resin with the WEST system pumps, well mixed, glue powder added and well mixed in, and at it with the brush.  This was a 30mm chip brush, cheap enough to throw away later, it actually costs less than the solvent you’d use to clean it so in the bin it went when the job was done.
Brush coat all of them, then four sides of the blocking  piece.

Drop one stave into the jig, slip another into the notch, then a third, sliding the assembly down and around as you do so so its sitting in the bottom of the jig.
Drop the blocking piece in, making sure all the ends are flush, then coat the top four sides of the blocking, and carry on with adding staves until the last two are ready.
Drop the second to last one in but leave its vee edge sitting up, you need to drop the last one into the vee of the one on the “other side” then lower both down so the vee engages with the square edge of the other.  You cant get it in otherwise, and its not possible to slide it in from the end.
Practice this on a dry run, do it a couple of times if you’ve not done it before.

Massage the assembly into shape so all the joints are fully engaged, then tie the assembled spar together by wrapping your shock cord ( or whatever) ties around it, work it over again to make absolutely sure its all properly clamped, then go away and leave it until tomorrow.

What you get when you come back is a peculiarly shaped thing, that will need a lot of work with a plane and sandpaper, and there are plenty of articles around that will explain that, but suffice it to say that you’ll make a lot of shavings, and that long strokes, changing the section from the odd shape to 8 sides, then 16 sides, then 32, then round, is the way to go. 
The part of the section that is going inside the aly tube doesn’t have to be finished to a high standard, its going to be completely smothered in epoxy glue before its slid into the (cleaned out with an acetone soaked rag on a broom handle ) aly tube, so with the aid of a template, a dead sharp no 3 Stanley plane and an angle grinder with a 40 grit disc on it, I made a big heap of shavings and dust.  It took a good hour and a half to get that fitting, patience is a virtue , as is a pair of strong arms.

So there it is, I’ve some work to finish the lower end, I need to cut the tenon that fits into the lower mast step and put a couple of screws countersunk into the aluminium to hold the woodwork in place, just in case the epoxy doesn’t stick, and its there to be a filler more than anything as the loads are all sideways, and that end of the job is done.
I’ll be back in a day or two with the top end.

Below, I've posted a series of pics that show the whole operation.

 Test cuts, note the blade of the saw tilted, the position of the fence and the height of the blade.

 16 staves, milled to thickness and all cut to width, the vee cuts done, drying out to make sure that the glue will take.

 45deg cuts to make 8 equal sides.

 The internal plugs, the reddish one is Jarrah, high strength but heavy, goes in the butt end of the mast, the other is spruce which goes in the top section. They're sawn to the shape of the inside of the 8 sided birdsmouth section spar pieces.

 This odd looking end cut is there to reduce the "stress riser" where the plug ends.

Second stave in place, all of them are pasted up with the epoxy glue so speed is needed. Note that I do this sort of work in the cool of the early morning to give me more time. 

 Thats three staves in place, now to slide them down lower in the jig, at this stage they don't have to fit perfectly, the final assembly with the shock cord clamps will pull them together.

 A nice close fit.

 Half the spar laid up, and the "plug" being fitted in.

 One at a time, laying them in over the plug that will reinforce the mast lower section.

 Last stave being slotted in. The last one requires the previous one to be eased out so the two can fit together then be pressed back in.
 All glued up and the shock cord strapping holding everything in place.
All strapped up. I'll leave this for 24 hours to make sure that the glue is dead hard.

 Time to make shavings.

 More shavings.

 Template being used, the open semicircle on the right is the template for the outside of the aluminium tube, the one on the spar is the smaller diameter for the inside.

 Almost there. Just some fine shavings and a bit of sanding to do.

 Hey, it fits! Now to pull it out,  clean out the inside of the tube, coat  the wooden section with glue and slide it back in with a couple of screws countersunk in, to hold it. Just for insurance.

The pile of shavings was about double this by the time I'd finished. It represents a certain amount of sweat, but it was a fun job. One to go.