Sunday, 26 April 2015

Toerails

Week 4

It looks like the epoxy plug idea is going to work. Made a mock-up of components to the correct dimensions and tried a couple of options: a) 6mm enlarged hole b)9.5mm enlarged hole.

Both were drilled 7/8" deep in the 1" deck simulation and filled with epoxy using a large syringe - so I could fill from the bottom up and avoid capturing air bubbles. Left to cure overnight they were drilled out to 5/8" with a taper drill for the screw pilot hole.

Meanwhile a piece of the toerail was countersunk to a depth of just under 1/8" and the rail plus bobbin screwed into both test sockets. The test piece was dis-assembled and then sectioned with the bandsaw to see the results:





The bottom is the 6mm socket. Here the screw just about breaches the socket sides, though the depth seems fine. This is not what I want, because there is a slight chance of water entering the wood fibres. In addition, the accuracy required to centralise the pilot hole exactly is going to be time consuming...

The 9.5mm socket accommodates the screw comfortably with plenty of lateral thickness spare.

The only slight issue is that there was quite a bit of absorption of the epoxy into the wood (good), this however leaves a surface depression (bad). This either means I have to make the epoxy thicker and overfill more than I did, or top up later...

Filled socket with pilot hole drilled awaiting bobbin & screw.




Sunday, 19 April 2015

Drawers down

Week 3

Should have a week and a half off before next job, so buckled down on Thursday and Friday to finish the drawers in the cabin.

To document the process, first mark out the pegs



I knocked up a little template for this, visible behind the piece on the bench - saves messing about with an over sized bevel gauge/

Cut out down the lines with dovetail saw


Remove waste with sharp chisel


repeat process for back of drawer until the pair are done. Lay out pieces and mark up corners

Choose a side and place to vice, lining up with a front or back so the top is flush. Mark out the dovetails from the pegs.


Cut down the lines. Using a fret saw remove the bulk of the waste


Repeat for the other end and remaining side. Mark out groove for the base and pass over table saw a couple of times. Cut appropriate size of ply for base, dry fit and prepare for glue up.

Bought deck paint, so will crack on with the epoxy sockets for the toe rails in the coming few days....

Monday, 13 April 2015

Spring Drawers On

Week 2

Work not as intensive as before, plus the Easter break allowed time to experiment with dovetails.Hawking around the timber store, came across some fairly manky Sycamore which had begun to be nibbled by the beetle.

Decided the sidings would be quite light, since the depth is only 5" or so. Cut and re-sawed the front/backs and sides then machined to 3/8".

Watched a couple of videos on various methods and set to. 1st drawer completed in a day, or just over. Wood is crap. Worm passages all through it. Soused the whole thing in preservative and later will seal with epoxy - when all said and done it's a drawer that will hardly ever be seen and it offends me too much I'll paint the bugger.

Weather warming up a bit and so decided whip round the deck / cabin joint with an epoxy fillet, just in case there were any air gaps or breaches in the glass overlap. Since not structural, used the fairing compound to bulk out, masked off and applied with tongue depressor. Turned out OK.



Also cleaned and sealed the two longest and the aft cant rails with epoxy. These will eventually be fixed over this fillet, bedded in with some vile ogg (yet to be decided upon...).

Second drawer attempted and completed in just under a day from bulk stock to dry fit. Timber much better as we move away from the end - hardly any beetle attack. Glued up overnight and cleaned next morning (today). Quite pleased for my 2nd only drawer.


Off to Poland for most of the week, but hopefully will get a couple of weeks off until the next country starts up.

Sunday, 5 April 2015

O & S

April, week 1

Right. That was a complete waste of time, then. The reinforcement strips on the underside of the hatch cover (despite being only 1/4" thick) still had enough spring in them to flatten the curve of frame and the beautiful snug replication of the deck curvature was lost. They were ground off and the cover spent a couple of weeks weighed down over the hatch to reinstate the shape, then another layer of glass epoxied on the underside as reinforcement instead - not sure whether to add a third layer yet...

The terminals of the toe rails were fashioned and dry fitted to locate screw holes. these are now done until I know I have an opportunity for a long-ish run at the job to sort out the oversized "epoxy wells" for the final attachment.





Other elements were treated with CPES (Clear Penetrating Epoxy Sealant) - these were things that will be bedded in to the deck somehow or somewhere, such as the cant rails around the cabin-deck junction and hatch surrounds. The assumption being that although every effort will be made to be sure the bedding compound will be waterproof, nothing is certain, so if there is any seepage hopefully the deck and the fittings will be protected.

Came up pretty well.




These will be rubbed down and an extra couple of coats of varnish added. They cannot be fitted until the deck has been painted, then the full 12 coats will applied to the exposed faces...

Moving inside and focussing on small jobs that can be fitted in after a day's work, I managed to find the locker covers for the well. Earlier I renovated the locker fronts and returned the starboard side to its original configuration (May '14). This means that one of the locker covers is too wide, another is too short - thought required for the short one.... However the swing catches were refitted and covers inserted. Not sure whether to convert some / one / all to drawers  - more thought.

In the cabin, the locker covers were also found; and here there already seems to be a collection of covers and drawers. I also recovered the bearers / runners to support the drawers or floors behind the locker front and under the bunks. Blimey, what loads were they expecting?? The riser was 1.5" x 3/4" as were the transverse bearers. You could have supported the whole bloody boat on them - given the aperture available to place anything in these lockers is about 4" x 18" it seems slightly over engineered... 

They were dumped. 

New runners were knocked up for the two drawers (nearest the bulkhead).





The remaining lockers only have loose covers i.e. the contents rest on a floor under the bunks, free to roll about anywhere they please as the boat heals. These too need to be converted to drawers. Rather than mess about too much, I will make plain drawers and screw on the existing locker covers. Its a bit of a cop out because they are far too heavy and I'm not over keen on their appearance, but I'm not wasting time on replacements at the moment. So this coming weekend sees an attempt to make my first dovetailed drawers.....

Sunday, 8 March 2015

Bobbins

March, week 1

An omnibus edition  of scraps of time stolen since last post.

The aft hatch has been virtually finished; glassed both inside and out. All that remains is a further coat of epoxy on the outside to fill the weave of the glass and then a dozen coats or so of varnish. The underside might get a couple of strips of iroko to reinforce (in case a lardy passenger decides to stand on it...).



Steps were taken to infill the the fillet left between the rounded deck edge and the rubbing strake.

During the glassing of the deck, the edge was rounded to allow the glass to follow the contours and maintain contact with the deck edge and  the hull planking. This now leaves a "v" shaped groove along the joint of the top edge of the rubbing strake. Clearly this will harbour water and cause rot, so needs to be filled. This is done with thickened epoxy, but first the rubbing strake needs to be removed, strips of polythene placed behind to prevent bonding of the strake to the hull and then screwed back up. 



Epoxy is forced into the gap and left to harden.



Later the rubbing strakes will be removed again and the excess sanded off.

The bobbins supporting the toe rail also need to be treated against rot. Although iroko, that is not enough in itself to prevent these rotting, so now the locations of the fixing holes has been identified, the toe rails are removed to treat the bobbins. A batch of CPES (Clear Penetrating Epoxy) is made up and each bobbin is saturated, with the CPES being absorbed by the vulnerable end grain and left to drain and harden on a rack. Later these will be dipped several times in varnish, ready for use.



Similarly the underside of the toerail was given a couple of coats of CPES.

Prior to toerail removal, the end blocks for the rails were roughly cut and glued to the underside of the rail extremities. It was easier to glue in situ, thus maintaining alignment and being able to clamp against the lands of the hull planking.The excess to be trimmed and shaped.

The fixing holes in the deck surface for the toerail now need to be over-bored.

Every opportunity to ward off rot is being taken with this rebuild. Deck fixings are notorious routes for the ingress of water and the birth of rot. On a compound deck such as this it spells disaster. Water can travel between layers of glass or bonded plywood and rot merrily for years until the evidence becomes visible; at which time the damage is almost always terminal, resulting in complete deck renewal. 

This is unfavourable. 

In an attempt to stave this off, I intend to bore out all deck fixings to at least twice the diameter of the screw being used and 1/4" deeper than the max. screw penetration. This hole will then be filled with thickened epoxy. When set, the epoxy plug will then be drilled and the screw driven home. When the moisture finds its way past the threads of the screw (as it inevitably will) it will meet with the impervious barrier of the epoxy plug and not migrate into the timber of the deck structure. This is all good theory, but in practice, a pain in the arse as there will be scores if not hundreds of screws driven into the deck.......................

Wednesday, 31 December 2014

Hatch two

Week 4

Sporadic progress through Christmas period.

Started the aft hatch surround a couple of days before. The plan is to keep the profile of the hatch pretty low, as the mainsheet anchor point is just a couple of inches forward f the leading edge. It will be all too easy for the mainsheet to snag on a corner and whip the bugger off during a gybe (as has been the case a couple of times in the past...).

So the height of the frame will be 3/4" max and will follow the curve of the deck - so no corners will be proud. As with the forepeak hatch, I have decided to use Iroko (from the same source). Due to the proximity of the rudder boss alluded to above, the encroachment over the deck also has to be low, so the overlap is only 1/2", with another 1/2" depth on the inside of the hole, making the thickness 1" in total...

The transverse (curved) pieces will be full length, the longitudinal ones will slot in between with a simple half lap at the ends. As before the assembly is screwed and glued in place with ample plastic sheet masking to permit removal when done.

All pretty good.

Now the hatch cover. The old cover could not be used because a) I reduced the size of the hatch by about half, b) the profile is now curved and c) it was a pile of crap.

This too was going to be light construction, The plan is to have it sit over the frame, so the clearance needs to small and the thickness of the edges also (rudder boss again...), But I wanted to reduce risk of sheets catching further, so the outer edge will be rounded (thus thicker to accommodate a curve). Therefore the front and back will be 1/2" thick and the outer edges 3/4". The top will be planked 1/4" Iroko let into the sides, again to lower the profile. The whole thing will be 1" deep...


Hatch cover frame after glue-up in situ.

All this means a fairly flimsy structure, prone to damage as people will inevitably stand on the bloody thing, so I will sandwich the top and underside with fibreglass (this will end up transparent and virtually invisible under the top coats of varnish), additionally there will be 3 strips of timber laminated transversely to the underside.

The plan was to book match the grain of the 1/4" planks of the top. Great care taken and all joints beautifully tight. Epoxy mixed, all clamped up and brought inside as temperature outside hovering around freezing for a few days.

 Big mistake. 

As the timber warmed, it dried and the sodding planks shrunk - so all my lovely close joints you can now drive a coach and four through.

Bollocks.

Time to fill.


Also decide to fill the butchery to the cockpit sides with some dutchmen using Burmese Teak I bought specially for the purpose.









Sunday, 14 December 2014

Rails and rubbers

December, week 1

Bit of a short week, fixed the toe rails and rubbing strakes. Toe rails were quite slow going, didn't want to over stress them, since they are being bent across their width, last thing I want is a scarph joint going "pop"...

All the pre-measurement was worth it - not a single deck screw fouled.




Details of the scarphs:





Work not stated on the sheetman's hatch (aft) frame and then the hatch cover.

Getting close now.....


Sunday, 30 November 2014

Iroko

Week 4

Last full week for 3 weeks before I disappear to Poland for a few months...

This was the week I tried to do the the Iroko baulk for the rubbing strakes and toe rails. I ordered the 1" diameter Iroko dowels for the  toe rail bobbins at the end of last week - hoping they would arrive by the end of this week (they came on Wednesday).

The Iroko bought earlier in the year was run through the table saw to produce 11 strips 14' x 2" x 3/4". Five of these were machined to approx 14' x 1.5" x 3/4"  (these would be the rubbing strakes) and five to approx 14' x 1.24" x 3/4" (these would be the toe rail capping).

These needed to be joined with 6" scarphs to produce 30' 6" lengths of each.

With these now unwieldy lengths, I needed some help to run them through the thicknesser for final dimensions of 3/4" thick and 1.5" and 1.25" wide respectively. This was an involved job due to the length and relative fragility (given the length - I'm always nervous of glued joints...).

Next was the job of knocking off the corners with the router; similar issues:



...but dodging rain clouds etc. worked out in the end, with the help of no.1 son and on Sunday the devoted life partner....

The toe rail cap was more involved. The rail is mounted on 3/4" high bobbins 1" diameter. The idea is that the rail covers the end grain so there will be a 1/8" overlap; it's therefore important the bobbins are central. The toe rail therefore needs to be pre-drilled with pilot holes - from the underside. If this cap rail is rounded first, it won't sit flat on the pillar drill stand - so it needs to be drilled before profiled.

In addition to this, I have to make sure the screws do not foul on the screws holding down the deck planks. This is where the polythene templates I made whilst cutting the deck ply some months ago comes to the fore, since I marked every screw before covering with the ply. Marking all the screws that might be in the way on the deck, the toe rail screw locations were marked out at 8" centres. Where there was danger of a clash, the location was adjusted so there was at least 1" clearance from any likely screw. These measurements were transferred to the back of the toe rail cap and pilot holes drilled for the final fixing.

The pre-drilled rails were then run through the router and the top edge profiled to a dome.

Next the bobbins needed to be centre drilled. Initial plan was to mount shortish lengths of dowel into the lathe and end feed a drill bit into the open end. However the end feed chuck did not have the tightest of bearings  (and why should it - it dates from about 1910...), so the holes  were not too central, plus the lathe stalled if the drill was fed too quickly, plus I was limited to the length of the drill; this meant only 4 bobbins at a time.....

The alternative was bore a 25mm hole part way through a 3/4" offcut with the pillar drill and clean out the edges 'til a bobbin fitted snugly, but could be extracted with relative ease. Placing this ersatz vice back on the pillar drill and centering with the original bit, it was clamped to the pillar drill base. Replacing the spade bit with a 4.5mm twist bit for the screw clearance hole, each precut 3/4" bobbin can now be drilled plumb centre - all 86 of them.

The assembly was temporarily clamped and a holding screw bunged in to see how it all hung together:-





Pretty good.

Ultimately the screw holes will be over-bored and filled with epoxy. These will then pilot drilled again for the final fixing. The thought be hind this is that if the epoxy deck covering is breached and the screw hole lets in water, the decks will rot from the inside out; by the time It is noticeable the chances are the whole deck will be terminal.... Not in my lifetime, thank you very much.

As a footnote, this is an unusual way to fix a toe rail. Father came up with this idea to minimise the possibility of water pooling behind a more traditionally fixed rail and rotting the deck (as it had some time shortly after he got the boat in '47). He used sawn off sections of broom handle for the bobbins - I'm sure he'd appreciate the upgrade.

As an aside, this construction makes it very handy to tie off fender ropes - no more screw holes in the deck for mooring eyes!!!



Sunday, 23 November 2014

Hatch

Week 3

With the wind up our tails and a 2 week postponement of the next job away, tackled the forepeak hatch surround.

But first, a play with my new toy. I had a struggle to flat off the epoxy deck covering due to clogging paper etc. and using a finishing  sander which really wasn't up to the job. My belt sander was too aggressive, so after seeking advice, bought a (bloody expensive) random orbit sander complete with dust extraction. This is something I had had stubbornly refused to acknowledge the need for since the barn was full of its own dust. But this beastie is different, the sanding pads are a net substrate coated with abrasive, the dust produced, which normally clogs paper, is sucked through it - extending the life of the pads by some measure. In addition the sander weighs only 2lb, a big advantage when I use it to prepare the hull planking.



What a piece of kit; sanded the whole deck in 2hrs and used just 2 pads. The vacuum extractor is so quiet, with the nifty trick of automatically switching on / off when the tool (any tool plugged into it) is in use. Still a little dodgy on my pins at the eye watering cost of it, but nonetheless, impressive.

Back to the hatch. Mulled this over for some time before and decided on profiles outlined here. The first thing was to find some Iroko long enough. An old wildfowling friend a few years back, gave me some bearers that had been used for shipping crates; they were to be tossed aside and burnt - he salvaged about 200-300 of them. All were tropical hardwood and some Iroko. They varied slightly in length, width and thickness; I wanted 4' long and 2.25" thick. There was just one and that was going to be tight to miss the bolt holes...

The cutting is quite complex because the frame is made up in 2 halves and glued in situ such that it can be removed as one piece if required later. The inner frame is screwed to the deck edge with simple mitre corners, the drip apron sits on the deck surface and is glued into a groove in the frame, then screwed into the deck (sealed with mastic). This hopefully results in a waterproof structure and fitting.

The inner frame pieces needed a rebate so the outer edge rested on the deck (for support and sealing), the depth of which was important as this would affect the total external width of the hatch. This width had to be matched with the inner dimension of the hatch cover. This rebate was cut on the router table. There was a second rebate 1/4" above the 1st to receive the edge of the drip apron. This too was 1/4" wide and deep and was cut on the table saw.

The drip apron pieces were 2" wide and only 1/2" thick. These had a corresponding 1/4" rebate cut on the lower edge and then the outer edge given a roll moulding. The dry assembly looking something like this:
  

The inner frame was screwed to the deck and drip apron marked up for the mitre:



These mitres were half lap jointed with their partner:



The whole area around the forepeak hatch opening was masked off with polythene and all the elements attached and epoxied in position.

24hrs later the assembly lifted out as planned and was cleaned up; the result being fairly good:



The final fitting will be delayed until the deck has been painted.

Next on the list was rubbing strakes and toe rails. The baulk of Iroko bought earlier in the year was sliced into eleven 3/4" strips 2" wide and 14' long - which means that each will need to be made up of 3 sections scraph jointed. Something to look forward to......