Copper-bottoming

We've had another productive but exhausting week at the boatyard in Totnes. The stanchions and guardrails are back in situ, which makes working on deck much less risky (the ramifications of a fall from height were too awful to ignore, so this was a priority) and the refitting of deck kit has continued. The big job, however, was to apply the Coppercoat antifoul system.

A yacht (not Maunie) suffering heavy fouling

For those not entirely au fait with the life cycle of the barnacle, boat hulls are perfect targets for the little blighters to set up home. If allowed to do so, they quickly encrust the underwater surfaces and, together with any weedy fouling, cause huge amounts of additional drag as you sail. Wooden vessels can also be afflicted by the teredo worm, particularly in warm waters, which bore into the planking with potentially disastrous consequences, so the battle against underwater invaders has been fought by sailors for centuries. Back in 1761 the Royal Navy first began applying sheets of copper to the bottom of their ships - it turned out to be an expensive but worthwhile process (hence the phrase 'copper-bottomed investment') as the copper repelled barnacles and also prevented the teredo worm from being able to bore into the timber.

Today, most yachts use an ablative antifouling paint, applied annually or (if you're lucky) bi-annually. Containing a cocktail of fairly unpleasant chemicals, the painted surface is soft so it slowly erodes, preventing barnacles and weed from gaining a grip on the hull. The annual cleaning and repainting process is the yachtsman's least-favourite task and, with the cost of a haul-out added to the cost of the paint, it's an expensive process. Also a key driver for our move from antifouling paint to Coppercoat was reducing the environmental impact.

Back in 2011 we had Maunie's hull slurry-blasted back to clean fibreglass, five coats of epoxy sealer paint were applied and then Coppercoat added. As its name suggests, Coppercoat is the modern equivalent of nailing sheets of copper to the hull; very fine copper powder is mixed into an epoxy base which is then applied by roller. The resulting finish is hard and provides effective anti-fouling for up to 10 years with nothing more than a regular scrub to keep the hull clean. After 8 years and thousands of miles, however, the coating on Maunie's hull was wearing thin so we knew it was time to apply a fresh coat. The yard quote for labour to do the job was close to £2,300 so we decided to do it ourselves; the manufacturers provided excellent instruction and videos so we braced ourselves for two and a half days of hard graft:

The first job was to sand back the old Coppercoat - a vacuum cleaner extracted the dust but a face mask is a vital extra as epoxy dust is pretty nasty

The sanding reveals the copper colour

The epoxy base is a two-part mix...

… and a drill-mounted mixer made it easy

The very fine copper powder is mixed into the epoxy - about 2.2 kg of copper per litre

Di at work. We applied an epoxy-only coat onto the hull first then five coats of Coppercoat, each applied when the previous coat was still tacky. You can see the white patches on the keel where the original Copper coat had worn thin

The trick is to apply very thin coats, so the first coat looked fairly patchy

After the third coat things were looking better. 

With just two people the process is hard work. Once mixed, the product has a pot life of only about 30 minutes so we had to work fast to get it all applied in time. One litre of mix was enough for a single coat of one side of the hull and we'd decided, wisely, to do one side of the hull at a time. Once we'd finished the coat, we had about 20 minutes of rest before starting the next mix.

Motivational donuts and coffee between coats

The end of day one, the hull half completed

End of day 2

The epoxy is water-based so didn't give off horrible fumes but it needs good air flow to allow it to dry. When we started the port side we found that there wasn't any breeze in the shed and the coating was taking an age to harden; luckily we were able to borrow a huge industrial fan which solved the problem in a few minutes.

While we were working, Andy the painter came to polish out a couple of minor imperfections in the paint. He has done a brilliant job.

The best bit of the job - removing the masking tape

Done! Well, not quite - after five days to let the surface harden, we need to move the supporting pads to coat the four patches of old surface that they will leave.

Maunie emerges gleaming - and our work begins again

On Wednesday afternoon a very shiny Maunie emerged from the paint shop and into the light. We are absolutely bowled over by the Awlgrip paint finish; Andy the painter is really an artist with a spray gun and she looks like new. Gone are the scratches, abrasions and other imperfections of 30,000 miles of voyaging, replaced by a completely smooth surface and a really deep shine. These photos don't really do it justice...

We now moved back into the big shed to take over the next bit of the project - putting her back together again over the next couple of weeks. As you can see from the last photo, there are some important bits to replace onto her stern but the really big challenge that we face is to refit all the deck fittings. The new deck is all but complete, with just some minor finishing work to take place next week, so we used the templates that we'd carefully made to identify the position of all the bolt holes, took a deep breath and fired up the drill!

The first task was to drill the holes for the feet of the pulpit...

… followed by the cleats and other foredeck fittings. Note the vital kneeling pad!

We used a good tip we'd been told about and drilled all the bolt holes 1mm smaller than the thread size; that way we were able to cut a thread through the polymer deck material which adds a further level of protection from water ingress. Of course, we added Sikaflex sealant / adhesive to complete the waterproofing so Di spent a happy couple of hours carefully applying masking tape around each fitting to prevent the black sealant from spoiling the look of the decks.

Blue gloves on for the Sikaflex - a ring around each bolt hole, followed by additional lines to bed down the fitting onto the deck. The felt pen marks on the fibreglass were used to locate the templates that we used to locate the drill holes.

Screwing in the bolts. Though we re-used the old fittings, the new stainless steel bolts have Allen-key socket heads which look neater and are much easier to undo than the old slot heads (should we ever need to remove them, which we hope we won't!)

The modified stanchion bases that Graham designed look great but have been a bit of a challenge to fit. Getting the bolt holes to line up has been an interesting challenge but we now have 6 out of 14 in place, sealed and bolted. We think they should work really well.

The first base in place and masked up, ready for sealant. You can see the grain effect of the Tek Dek and the very neat, no-caulking fit against the fibreglass of the bulwark.

After two and a half days of very hard work, we were glad to be heading home for the weekend (especially as it absolutely tanked it down with rain all day today). When we next go back to Maunie we will continue with the deck work and also have the prospect of a full day (or more) of applying new Coppercoat antifouling. Living the dream, as they say!

Battleship Grey

The Maunie project is now progressing quickly. On Wednesday, Rick came back to glue the main decking down and he sent us these photos - we think it looks fabulous:

Meanwhile the Baltic Wharf Repairs team has set-to with orbital sanders to smooth back the paintwork on the hull and fill in any major war wounds from our sailing trip. She was then moved into the spray bay and was given a first coat of primer so she's currently sporting a battleship grey look.

The first coat of primer exposes any minor imperfections and blemishes so, when we visited this morning, the team was busy with fine-grade filler to make them disappear when the next coat of paint is applied.

A couple of minor cracks in the gelcoat needed more intensive surgery with epoxy 

The stern, with redundant bolt holes for the bathing ladder (which we won't refit since it keeps snagging the mooring lines on our river mooring) filled and faired

By the end of this week she should have her white glossy topcoat applied and the following week she'll be masked up for her blue stripes; we know she'll look better than new. The Baltic team has just completed a really major insurance job on another yacht which broke free from its mooring in a gale and hit rocks - they had to rebuild a huge, gaping hole in the starboard quarter but, as the late Eric Morecambe would say, you can't see the join! The paint job is superb.

Applying the sticky stuff

There has been more hands-and-knees stuff over the past few days, cleaning the vestiges of old black sealant from the sides of the pilothouse and the bulwarks where the old teak met the fibreglass. The new deck is slightly thinner than the old teak and it'll meet the fibreglass with a clean 'wood' edge rather than a hide-the-evidence fill of black caulking (which would inevitably degrade over time) so it was vital to get it clean and polished.

It was an extremely tedious task, starting with a scraper blade, adding solvent to soften the sealant, before moving on to progressively finer grades of wet-and-dry abrasive paper (400, then 800 then 1200 grit), applied by hand and wet. Finally rubbing compound was used to remove the final scratches and return the shine to the fibreglass. Oh, and a few bits of damage had to be repaired with gelcoat (mixed with pigment to match the off-white colour). Two solid days was how long that paragraph took to do. Aaargh!

Anyway the good news is that Richard the deck specialist returned yesterday to complete the trimming process and then began to weld and glue the deck into place. He makes it look easy but it clearly isn't!

The two halves of the deck had to be joined at the central king plank on the foredeck. Gym weights hold one side in place and strips of polymer 'welding rod' are cut to size.

The polymer ready for welding

The hot-air welding tool - the polymer rod is fed down the nozzle which melts both it and the edges and base of the deck groove into a homogeneous weld. A sharp chisel cuts the black flush with the deck and then an abrasive scourer brightens the darkened 'teak' and restores the grain effect.

Applying the glue - which also delivers a further waterproof barrier to the fibreglass deck. The new deck is rolled back to allow half to be glued at a time then a high-tech rolling pin is applied with lots of manual pressure to remove any bubbles or high-spots. 

With all this care to make the deck fully watertight, we are determined to avoid drilling holes into it wherever possible. One of the biggest causes of deck leaks on yachts is where the stanchion bases are drilled through - the stanchions hold the safety guard wires around the deck and can be subjected to some big forces on their three, 6mm bolts. If the stanchions get pulled on (by someone hauling themselves up from a dinghy, for example) or stressed by hitting a dock wall, the sealant gets damaged and leaks begin and, of course, being at the low side of the sloping deck, they get subjected to a lot of seawater and rainwater.

So we thought about an alternative option to make brackets to bolt the stanchions to the bulwarks (the little upstand of fibreglass hull above the deck). Graham spent many happy hours measuring and making plywood templates.

Naturally the angle and height of the bulwark changes as you move aft, so four different designs were required to make the 7 stanchions on each side fit

One of the finished bases being checked for fit

This is certainly not a cheap solution and the drilling of holes for the fixing bolts is quite a challenge of geometry but it saves 28 holes in the deck each side. With other fittings re-positioned or removed (we've even shortened the yankee sheet car track to suit the extremes of adjustment that we use), we've removed a total of 96 holes from the deck - that's got to be good. There is no way we're going through the pain of finding wet balsa in the deck core ever again!

At last, we are able to leave Maunie for a couple of weeks. This morning she was moved into the Baltic Wharf Repairs workshop - her white hull will be lightly sanded down, the scars of her collision with a mooring buoy in Suva Harbour will be filled and she'll get a new gleaming coat of specialist Awlgrip paint (several actually). Then, after about 3 weeks (we hope), we'll move her back into 'our' shed to refit all the deck fittings and we'll apply four new coats of Coppercoat antifouling. So there's lots to do still but it's all positive now, adding things back rather than stripping things down.  

Good progress - the poorly deck is better than new

David Sharp, owner of Baltic Wharf Repairs, came to our rescue to perform a superb repair to Maunie's deck. He first epoxied in a new foam core to replace the balsa, together with two marine ply pads (correctly positioned, this time!).

His ace fibreglass man, Andy, then came in to grind down the edges of the existing deck to a nice gentle taper and then applied six layers of bi-axial fibreglass cloth, each epoxied into place.

Edges of the deck ground out to allow the new fibreglass to provide a strong lap-joint to the old

New glassed top section

Epoxy filler to provide a perfectly level surface

Having watched this process being done, Graham thinks it's something he could probably do himself but he's very pleased that he got Dave and Andy to do it!

Meanwhile, though, Graham was engaged in his own epoxy story - fairing the surface of the rest of the deck to fill the holes left by the plank pins and other deck fittings and also levelling the divots left during the chiselling process. 

Once the epoxy had hardened overnight, the final stage was to sand and vacuum the decks. A time-consuming process! However, so far we reckon we've saved about £9,000 in yard labour costs by doing all this preparation work ourselves.

So, the good news is that the hard and dusty work is almost over. Some detail sanding and polishing remains to be done to remove the last residue of sealant where the old deck met the cabin sides (a full, fun day on Sunday should see this completed) but the new deck has arrived and the fitting process has begun!

Rick, the deck specialist, unwraps the parcel

Starting the fine-tuning of the fit - a small plane is used to trim the edges. There won't be a line of black caulking at the outer edges so the fit needs to be exact and the fibreglass needs to be clean and polished before the deck is glued into place

We'll post some photos when it's finished.

We left the boatyard on Friday evening, both of us feeling pretty shattered after a full-on week. However, we managed to keep our sense of humour through the tougher moments and Di's skills have been applied to lots of the jobs that Graham finds just too detailed and fiddly.

Surgically removing the lettering from the stern ready for the repaint

What we really hoped we wouldn't find

With Graham's new favourite toy, the Draper Expert SDS chisel drill, helping us get the last of the teak off the deck, the next process was to use a multi-tool blade and then an orbital sander to clean any remaining wood off the fibreglass. Slow and tiring work for us both but out $60NZ Chinese vacuum cleaner has worked wonders to keep away any harmful dust.

Di working wonders with the multi-tool

Our back-of-mind worry with this project was always that the fibreglass deck below the teak planking might be damaged. The challenge is that it's actually a sandwich: two layers of fibreglass (each about 6mm thick) encase a middle of end-grain balsa wood (the grain pointing upwards). The advantages of this construction are that the balsa gives good compression strength, it delivers excellent thermal insulation and, of course, it is very lightweight. The disadvantage is that if water gets into the sandwich, the balsa quickly rots and turns to mush. Knowing this, we always fixed any deck leaks as soon as we found them by renewing the caulking. Oh, what fun in the sun!

In the Aussie sunshine 3 years ago

Our biggest concern is that when the teak was laid, back in 1997, it was held in place with pins drilled into the fibreglass at roughly 6" intervals until the glue had set. The pins were then removed and the system left several hundred 4mm holes in the fibreglass, relying on the caulking to keep them covered. A fairly poor system but perhaps better than the alternative of using permanent wood-screws.

Finding the holes during re-caulking - we made sure we injected sealant into each one

So we hoped that our diligent maintenance would have paid off and now, with the teak gone, we used a counter-sink bit on the drill on every hole so that we could fill them all with a permanent cap of epoxy.

This process had a further use - by applying considerable pressure in the drill to countersink the hard fibreglass, we could confirm that the sandwich deck was in good order. The tell-tale sign of a damaged balsa core is that the top layer flexes under pressure. All good, we thought, congratulating ourselves on our effective deck maintenance. Until, that is, we reached the port side deck above our cabin. Did that area flex a bit just then? No, surely not! But yes, it definitely did. Bugger!

We drilled a couple of 25mm test holes and, rather than finding dry white balsa, we found black mush and a very unpleasant smell of rot. Bugger. Nothing for it but to cut open a section of the top fibreglass..

The sight and smell made us feel very sick. Nothing for it but to cut a bigger section in the hope of finding balsa that didn't ooze foul liquid when pressed. Alas, the next section was even worse:

The four holes are for the main shroud chain plate - a high-stress part of the hull, so it was definitely a worry to find this here. Nothing for it but to cut more deck open.

And now we had a real worry. The builders had sensibly used a pad of high-strength marine plywood, rather than balsa, around the chain plate but had obviously got their measurements badly wrong! The plywood was about 15cm too far forward, so two of the bolts went through strong ply and two went through soft balsa - all to a stainless steel bracket bolted to the hull. As a result, we are guessing, there'd be some differential compression and movement of the deck, enough to allow a slow but significant leak to invade the core.

In all we cut away about a 1.2m of deck until we found sound, dry balsa core and we also chiselled away two pads of wet plywood. It wasn't our happiest moment but it had to be done.

Di's hair-dryer used to ensure that we got everything dry

Back to clean, dry balsa

On reflection, after a long day and a glass or two of wine, we feel good that we found the problem and, like dentists drilling cavities, we'd cut out all the rot. The next challenge of course, is to repair the decks. Modern closed cell foam will be used to replace the balsa, high-tech epoxy will seal it and layers of fibreglass will be laid to make the new top of the sandwich. Not by us, this is beyond our comfort zone, so David, the hugely capable proprietor of Baltic Wharf Repairs will step in to do the fix over then next few days. More £££'s of course so we are talking to our insurers to see if this might be covered under the 'Latent Defects' clause.

Talking of hugely competent people, we managed to get help with the removal of our anchor windlass which, despite the treatment of penetrating oil and a large hammer, refused to come apart. Steve, who runs New Wave Marine (engine specialists) here, is hugely overworked but Graham managed to get him to accept the challenge and the two of them worked through lots of options and eventually used a 10-tonne hydraulic hub-puller to persuade the gearbox to part company with the shaft to which it has been attached for 21 years. Steve went beyond the call of duty on this, climbing into Maunie's cramped anchor locker but, after about an hour, the gearbox was finally off and we could remove the shaft from the deck to allow the last few shards of teak to be chiselled away. Phew!