Precision Required

It’s still March (2020). It’s BCSD1 as far as the blog is concerned (just). Loyal readers (all two of youwill notice that there is no time lapse video in this post. The management apologies for this omission – it was initially due to a memory lapse by the operator and then a shortage of critical equipment meant that this facility was temporarily unavailable.

It’s time to fit the centre board case. As they used to say on Blue Peter 2, it’s something I made up earlier – a hollow open sided rectangular box about 4 ft long x 2 ft high x 2 inches wide 5. The long top and bottom sides are open so I leave you to imagine how flexible the whole thing was.

The snag is the inside needed to be lined with glass fibre cloth and I could not work out how to do this after the box had been assembled, so I made it in two L shaped pieces – each consisting of a big side slab and a little end flap. Glass fibre cloth was epoxied in place on the inside surfaces of the L and then, once everything was fixed but not totally cured, the two L were married together. Thickened Epoxy was slathered over the inside of each end and a piece of glass fibre tape was lowered through the slot and pressed firmly into the goop. Not particularly pretty, but I hope effective.

Now back to fitting the slot into the hull.

I needed to climb into the hull. This would be the first time I’de attempted this feat. Would it take my weight? The hull has a 4 foot long slot in it where the centre board case will fit, between the left and right (oops, port and starboard) sides of the bottom plank (sorry, plank 1 7). So the bottom of the boat is quite bendy without the slot glued in place. Fortunately, the underlying trailer has a convenient transverse beam in the right place and there were a few pieces of 18 mm plywood lying around so a pair of supports were made to hold up the planks and there was a space for the centre board case to fit between them as it  protruded through the hull.

I climbed gingerly into onto the hull – there were a few creaks and groans but no rending sounds so the first test was passed. The centre board was “offered up” and the slot was found to be slightly short. Easily fixed with a rasp.

But then the implications of this slot hit home – if it wasn’t lined up longitudinally and vertically true to the hull, the centreboard would be all wonky and she wouldn’t sail at all well.

Back to all that wearing alignment of the hull with the laser guide. I needed to use the camera mount to hold the laser level…(in this case for a vertical line).

Laser display

This turned out to be quite simple and the case was soon lined up and tack glued into place.

The following day I mixed up lots of Epoxy, thickened it with filler, wetted the joints with un-thickend epoxy, soaked yards of woven glass fibre tape in un-thickened epoxy and glued the case in place with lovely filleted joints.

Phew.

Notes

1 Before Corona Shut Sown

2        

File:Blue Peter.gif

Blue Peter 3

                                                                              

3 Not that Blue Peter (international code flag P). I mean the childrens programme on BBC TV (is it still being shown?) where the presenters made stuff using sticky backed plastic 4

4 I never got a badge

5 1.2 x 0.6 x 0.05 metres. 6

7. See nomenclature in a previous post “And a few steps back”

8 I’d left the laser display board at home and Samantha too 4

9 Apologies to I’m Sorry I haven’t Clue and the late Humphrey Littleton.

Mad March winds

It’s now (in real time 1 ) the second week of March. The last three weeks have seen almost continuous rain and strong winds across the UK. But the builder and the owners agent have not been here to experience them. We’ve been skulking in the antipodes, in relatively benign conditions (except where we particularly needed clear weather). Now back in the UK we find the local intermittent chalk stream in full flow – the first time for over four years – as the water table has finally risen above the spring line. The local fields are sodden and trodden into seas of mud by cattle or horses. But the daffodils are coming out and there’s even a sign of green leaves on the local blackthorn.

Enough of these nature notes: I wonder how the cow boatshed had survived this turbulent atmosphere.

So, we awaken Martina from a four week slumber and trundle north west, along the valley road. Then up rocky lane, passing a sea of mud where HS2 work is restarting. Through the various copses before turning onto the farm. Still up, past the old chicken sheds, turn left by the yellow (sometime) site office, towards the bonfire site.

Somebody has helpfully put a skip in the way. Turn towards the scouts canoes and then reverse down the track to park outside the shed doors. But do make sure you miss the old site loo.

So far, so good.

Past the scouts canoes, a digger other useful stuff

The empty plaster tank is still there – so perhaps no one has been in. Slide it away and open the doors the would be boat is still there – a trifle damp and dusty but unchanged from when I last worked on it. It’s blowing hard outside, the roof creaks and groans and the sliding doors rattle on their rusty tracks. But we must get on.

Mind the old loo
The doors had not been touched!

Bring in the tools. Light the fire. Fetch the water. Today is rubbing down day.

Before I left at the end of January, I had tacked in place a couple of longitudinal bulkheads that make up the cockpit sides. First positioning them and holding them in place with cable ties and then “tack welding” their edges in place with little strips of mixed epoxy.  I’d put the sides and end of the engine bay in, too and held the transom against them, using the former supplied to bend it to the right shape. All these “tacked” joints need  to be roughened with sandpaper before a glass tape covered fillet can be laid over the joints.

So that’s todays weary task. The spaces are too small to get at with an orbital sander, so it’s all to be done by hand. The dust gets everywhere. The vacuum cleaner 2 howls in the background in an attempt to keep it down. I’d forgotten to don my overalls, so my clothes became dusty too. My hair became whiter that ever – but a least I had had the sense to wear a dust filter mask.3

After several hours of finger and hand weary work, the job was done, the obvious dust cleared from the boat and the joints all rubbed over with a tac rag or two. 4

Another day: now to start filleting the joints.5

Filleting a joint makes the glue joint very strong. You mix up a large lump of polyester resin and hardener and mix into it a filler material that bulks it up and makes it stiffer. This is then spread along the joint and shaped to make it appear a bit like the coving between a ceiling and a wall. Then glass fibre tape is coated with more mixed resin (this time without the filler) and laid along the joint, Two or three layers are applied. It’s very messy and sticky and has to be done quite quickly otherwise the resin will set before you have finished.

The joints between the longitudinal bulkheads and the planks of the hull were each about 3 metres long. It took me ages. Then there were some fiddly small ones to do around the engine housing. But they are yet to be done.

I hope that I can now walk on the inside of the hull so that I can put the centre board case in place.
Almost looking like a boat

Notes

  1. Now there’s a phrase that’s worth conjuring with.  It seems that neither physicists nor philosophers can agree on what time is or how it is made up, let alone why it can’t run backwards.
  2. Not the household one, the owners agent takes a dim view of such items being misappropriated for unofficial uses. It’s the one used to clean out the pond.
  3.  was not trying to avoid  Corona virus – having spent several hours in the terminal buildings in Hong Kong last week, I don’t think there’s much point. I’ll just self isolate in the boat shed for a couple of weeks
  4. If you haven’t come across these things, I recommend them for the final clean of surfaces before they are painted. The tac rag is a cloth impregnated with some sort of sticky stuff (a bit like a fly paper, I suppose). When you rub it across a surface that you think is clean it’s amazing how much stuff is picked up.
  5. No, I’ve not started a butchery business (although, looking at the quality of the carpentry, some might think so).

Beware Boarders

Hello readers. Are you sitting comfortably? We’ll I’ll resume my jottings anyway. 1 Regular readers will be agog, sitting on the edge of their seat, chewing their finger nails to the quick, eager to find out how I solved the cracked plank that I mentioned at the end of the previous edition. It involved a long piece of flexible batten, a couple of G clamps polythene sheet, some woven fibreglass tape and a large slurp of mixed epoxy. The crack had occurred as I was attempting to bend plank 2 on the starboard side round the edge of the first transverse bulkhead. The intention was for this plank to take up a nice, smooth, sexy curve as it bent round the first and second transverse bulkheads towards the bow. It was too much for the plywood, despite it being softened by pouring boiling water over it. Instead of the sexy curve, there had been a significant sharp cracking sound and the plank had taken up a definite kink. 2

My proposed fix for this was to persuade the plank to adopt a better curve by using the batten and the g clamps to provide it with a pattern to follow and, whilst held in shape by this pattern, stiffen it in this position by gluing fibreglass tape to the inside of the bend. The snag was that I didn’t want to bond the plank to the intermediate bulkhead and that’s where the polythene sheet came into play. I could wrap this round the edge of the bulkhead to keep it and the plank apart whilst the epoxy set.

So, one morning in early January, I set off to the cow boatshed with this project in mind. I had by now settled into a routine. Arrive at the shed, open the sliding door and sidle into the “dirty” area. Here I stored fuel for the wood burner and also used a small pile of pallets as a platform for very messy activities:  chain sawing the pallets to provide the fuel and sanding down boat bits as needed. I’d then light the wood burner and spend an anxious few minutes whilst it decided it was going to work that morning – it’s very dependant on wind direction. Then once it was burning, it was a question of stuffing it as fully of wood as possible and then keeping an eye on the burn rate, fiddling with air vents and damper accordingly.  Then the ancient transistor radio is coaxed into life – BBC radio 4 is usually the station of choice but I do draw the line at the Archers…..

Now I can get down to work. This morning was a little different – I had some welcome boarders. They needed collecting from the farm gate 3 and then given a demonstration on the project. Although the kettle had been put on the stove when I lit it, I couldn’t offer coffee or tea – I have not provided the workspace with mugs (or coffee). 4

Boarders or visitors?

Despite this interruption, I was able to complete the kink removal project that day.  I had the woodburning stove roaring away (kettle singing merrily on top) and an infra-red electic patio heater glaring down on the plank to set the epoxy in about 3 hours. And it worked – the plank had taken up a nice sexy (not kinky) bend.  

With some trepidation, I then proceeded to put the port side plank 2 in place. I managed to learn from my mistake, persuading it to fit smoothly into position. Both sides of this plan were now secured in place with the usual crop of cable ties.

The fire had gone low, and there was little usable fuel left, so to round off the day I attacked a few pallets with the chainsaw and stacked the resultant firewood beside the stove for the morrow.

Notes

  1. One of the issues I find with writing a blog is not really having a good picture of my reader (s)  You are either one of the four faithful followers of this occasional stream of consciousness about building a boat, or you have chanced across it.
  2. Despite the term “kink”, it was certainly not kinky, nor sexy.
  3. Well, I couldn’t let their newish car become sullied by the usual messes in a farm.

It’s almost the New Year

Don’t forget, we are still in B(oat) time at the moment. Immediately after Christmas I had been rather pleased with progress, even though we had taken a couple of steps back. But we had stabilised the platform on which the bloody boat 1 and I was keen to press ahead with the build. I refitted the second plank, fixing it in place with the cable ties. I was now a little worried about how the whole lot would come together. I knew I had to fit in place a few cross bulkheads and it looked to me as if they would be tight to get in place.

So far I had been following a build plan that seems to be generally accepted in the various books on building plywood boats – stitch the planks together then fit the cross members before using epoxy to glue it all together. However, I could see that this might be difficult. My stature is that of the hooker of a third fifteen rugby team before the game went all professional – short and stout 4 – and I knew I would not be able to reach over the top of plank three to apply epoxy to the seam on the bottom plank ( I could barely do so over plank 2). 5 It was pretty obvious that the assembly would be far too loose to maintain it’s shape if I tried to “get aboard” to apply epoxy. …. I decided to abandon accepted practice and revert to the way I built model ships when I were a lad. Put the bulkheads in first and then fit the planks.

So, off came the plank 2 pair: I cut out the three full width cross bulkheads and the partial one that is to be situated at the aft end of the centre board case and which will form the aft end of the water ballast tank. (Did I say this boat was to be lightweight and water ballasted – well, if not, you saw it here first.) All these items were then positioned on the bottom plank and cable tied in place. Getting them in the right place was easy because the programme for the CNC machine had included blind slots in the planks to mark the position of the bulkheads.

This all seemed to work really well. The bulkheads went into place on plank 1 – with a bit of effort. I had to use cargo straps to hold it in place round the curve by the first bulkhead and to hold it in place with a temporary wood screw through the plank into the bulkhead.

The first two bulkheads – note the strap.

Nevertheless, I blithely proceeded to refit plank 2. And here’s where trouble hit. Despite the application of hot water to soften the plank, 6 there was an ominous and sharp “crack” as I forced the starboard plank into place, aligning it with the top of the bottom plank. Instead of the plank taking up a smooth curve round the edge of the first bulkhead, there was a rather pointy corner and no smooth transition from the bottom to the second plank..

Another problem to solve – and would the dreaded twist return?

I retired for the day to think about it.

Notes

  1. As the Owners agent refers to the whole project. 2
  2. This has been the soubriquet 3 that the Owners Agent has applied to all the boats so far
  3. The editor advises me that, strictly speaking, this term applies to the nickname given to a person. Boats do have (or acquire) a personality so I have overruled the editors objection.
  4. Not a teapot, for those of you who remember the rhyme
  5. I refer you to nomenclature in a previous post
  6. I had (fortunately) placed the full kettle on top of the woodburning stove that morning!

And a few steps back

Perhaps my enthralled readership has a more retentive memory than mine, 1 nonetheless I will adopt the practice of the Television producer and tell you what happened in previous episodes. So, if you can remember, skip the rest of this paragraph and move on. Still with me – I’m glad I’ve got company. I had been happily stitching the first couple of pairs planks together, leaving the cable ties loose to enable manipulation at a later date. I’d even got as far as fitting the top plank 2 to the port side of the boat when I discovered that I had managed to stitch a twist into the prow. Now read on.

No amount of pushing, shoving, twisting or other manipulation had any effect – so much for leaving the stitches loose. Here’s where work to a step or two backwards as the top and middle planks were taken off.  I wondered if I had problem of alignment with the trailer – this is being used as the build base for the boat, so I spent several fruitless hours using 17th Century methods 3 to level the trailer fore and aft and from side to side and checked the vertical alignment too (just in case gravity was misbehaving in the shed, under the influence of B time). In the end I gave up and spent fifty quid on a simple laser level isn’t click and collect a great invention. What did we do without Screwfix and Toolstation (to name but a few)?4

The following morning, after lighting the fire, I started to play with my new toy. It took me some time to work out how to get it to “self level” but once I had done so, I was away I made a “surveyors pole” and leapt around the place trying to find out how level the trailer was. Little progress was made until I started noting the readings at the various points (note 1 applies). Then I was off and the trailer and pair of planks were at the correct attitude.

The trailer was levelled from side to side and then fore and aft. Gravity seemed to be pointing downwards.

I thought we’d made progress.

But we still had a twisted prow.

I inspected the port and starboard examples of plank 1. 5 In theory, they should have been perfectly aligned one to the other, because I had matched and clamped them back to back before drilling the stitch holes. Practice had not read the theory, because I noticed that the two halves of this plank did not quite align fore and aft – the starboard plank was about an eighth of an inch forward of that on the port side. I convinced myself that this could induce the twist and, with a few light blows of a heavy hammer, moved them relative to each other and

 (drum roll)

the twist was fixed…..Full steam ahead tomorrow. But it was Christmas so that ended work for a couple of days.

STOP PRESS

I knew I had a reader! I’ve had a comment to the blog. Saxisgood wants to know where the coffee maker is in the main workshop. Baldly, there isn’t one. It’s not a matter of power supply capacity (although the lights do dim when I power up the angle grinder). Nor is it a matter of the builder not liking coffee. The delicate fact of the matter is the absence of any facility to dispose of the used coffee…..

NOTES

  1. My Latin master (a long time ago) accused me of having a memory worse than a sieve – ‘at least the sieve retains something’ he said. I agreed and went on to fail Latin 0 level more times than I cared to count. This condemned me to study engineering at the “Godless institution in Gower Street” rather than reading “Natural Sciences” at some Oxbridge college.
  2. I understand from the designer that my terminology is incorrect. The bottom plank (which to me forms the bottom of the boat and therefore should be so named) should be called plank 1, with the subsequent planks numbered accordingly. So the top plank should be called plank 3. Given the problem referred to in note 1 (see above) I suspect that the nomenclature will become pretty confused throughout this blog.
  3. Or probably much earlier methods
  4. Please note, I make no claim to be an influencer. This blog does not monetise its click rate.
  5. I warned you about nomenclature.

A few steps forward

Welcome back, my patient reader. In the previous blog I posited that the boat build has it’s own B space / time continuum and I should have made clear that this blog is included within it. At the time of writing the blog is just about in the third decade of the 21st century CE. The author has to bring it a little closer to real time as he is forgetting where he has got to (something to do with that incurable disease we all get – AGE.

During the Festive Season I was able to escape from some family duties to the Small Items Workshop1 where I had placed the components for the centreboard, rudder and rudderstock, before the Christmas break. In between Mince pies and Turkey sandwiches2, I found time to assemble these parts.

The centreboard is comprised of 5 layers of ply: each of the middle three sheets has a hole cut into it so that sheet lead can be added to increase the righting moment provided by the centre board as the boat heels. After gluing four of the layers together, sheet lead was added to fill the hole and the final outer layer of ply was bonded to the complete the centreboard. But it is still not finished – it awaits being profiled by the angle grinder  3 and then having glass fibre cloth glued all over it.

It will have to go to the boat shed for these messy operations.4  A roll of lead sheet was purchased from the local builders merchant at great expense, the lead was cut into lengths to fill the hole; 12.5 kilos of lead in all.

The middle three sheets of the centre board and the 12.5 Kg of lead

The one half of the bottom of the boat (sorry, plank 1 to use the designers terminology) was placed on top of the other and matching holes drilled along their mating edges. The first cable ties were threaded into place and then the bottom was unfolded. The ports and starboard second planks were then stitched to the outer edges of plank 1. It was beginning to look like a boat.

Adding more planks

An attempt was made to fit the top plank but I noticed a problem – the prow had developed a alarming twist……this was nothing to do with the recent New Year celebrations.

Was the twist eliminated? – find out in the next exciting instalment of Riff Raff – Build a boat.

Notes

  1. The Small Items Workshop (SIW), is the garage and is integral with the house so the permission had to be sought from the Owners Agent for this to be allowed.
  2. I’ve been reminded by the Owners Agent that the family (including me) had delicious roast fillet of beef for Christmas lunch. OOPs – I hope my Vgan readers are not upset by this revalatiion.
  3. I would point out that the angle grinder is not a semi autonomous machine – it does require an operator.
  4. The Owners Agent is very clear that such operations are NOT to be carried out in the Small Items Workshop

Starting

Gentle reader, you have probably realised that the boat build has it’s special B time/ space1 and the builder has been lost in B space for the last few months.

Nonetheless, I think it’s time that I ensured that B time and space coincides with normal time: after all, it is the start of a new Decade.

I hope you have enjoyed the festive season. The Owners Agent and I have been mildly cultural, taking in a ballet and a couple of exhibitions in London rounding it off with the latest in the Star Wars series. But the boat build has not been forgotten and it’s probably time to get this blog up to real time.

I left you (only last week) in late October, having brought the flat pack boat to the tent in the cow shed, now known as the boat shed. The sheets have been unpacked and some of the parts have been cut out and it is now time to make a start. There’s a lot of gluing to be done.

Several of the components are more than eight feet long 3 ,which is longer than the plywood sheets – so they have to be joined. They have cunningly shaped fingers at the point of the join – the slight snag was that they were cut from the sheet with a slightly under sized cutter, so could not be coaxed together, even with a large mallet. Happy hours were spent fettling the parts to fit. The weather turned cold which would have made the curing of the epoxy glue a long time affair (if ever). So, with the Owners Agent’s permission, these were brought to the warmer house.

The “fingers” forming the join of plank 1 – the bottom of the boat

The gluing went well but there was then the problem of taking these now long and flimsy parts back to the boat sheet. A couple of builder’s old planks4 solved the problem.

Now it was time to get the workshop really ready!

Getting ready.

But B time is still several weeks behind normal time.

Notes

  1. L space derives from Terry Pratchett and the library at the Unseen University. Time slows down in L space and all L spaces are interconnected2
  2. At least, I think that’s the idea – go and read the books yourself
  3. Approximately 2.44 metres for those of a Napoleonic disposition.
  4. Remember, the boat shed was a builders junk lot after the last calf had left.