Sunday, 17 August 2014

Drilling holes

Week 2.

With the deck ply finished, there was no excuse to delay drilling the hole for the rudder, a job that had exercised my little mind for some months. 

Critical to get vertical and central, throughout the rebuild process I had tried to maintain the original position by leaving a central pilot hole in the deck; 

however, dropping a plumb bob through the hole it appeared to be off a little to the port side. Enlarging the hole by increments (keeping within the confines of the ultimate 1 7/8" hole) I was able to fix the position. Temporarily tacking on a guide plate over the adjusted and now oversized original guide hole, I was able to pass through the hole saw drill extension that would allow the drill to be above the deck and the hole cutter below.

On the underside of the hog I scribed the centreline, through which the pilot drill would hopefully emerge... and started cutting:

The depth of cut was limited to the depth of the hole cutter - about 2 and a bit inches. The thickness of the hog is about 4 and a bit inches, however I had bought an extended pilot drill, so that hopefully, once I had reached the limit of cutting depth, the pilot drill would have emerged from the bottom:-

Spot bollock (as they say) - bugger me, the plan was working.

Dissembling the extension bars, I was able now to attack from the bottom, hopefully using the established vertical pilot hole to maintain alignment, thus the hole was completed.

A little bit of misalignment, but it is not possible to fully tighten the cutter to the arbor for some reason (some German logic I'm sure from the designers in Bosch, but it confounds me) so it is more than likely this was the cause for about a 1.5 mm deviation at the meeting point of the two cuts.

Turning attention to the top, I now needed to be sure the top hole was also vertical. If this were just deck (3/4" Douglas fir planking and 1/4" ply), I wouldn't be too bothered, but because this area also takes the eyebolt for the mainsheet, there is a wacking great lump of oak reinforcing it between the two deck beams:-

So things have to be a bit more accurate. I decided to rig up a couple of right angle braces; one laterally and one along the centreline and adjust them so they were both vertical.

Then placing a long shank drill bit in the chuck, brought the two together until the drill was vertical in two planes, and would remain so as the cutter descended:

Swapping out the bit for the hole cutter, the time had come...

A check with the plumb bob seemed to confirm all was OK; at 12 o'clock and all points East, West and South, the string touched both top and bottom holes - she was plumb.

Only now I could accurately measure the final depth from the top of the wooden boss on the deck to the underside of the hog and have final adjustments made to the new rudder shaft that has been sitting in the fabricator's workshop for over 6 months; so a trip to Hoveton to finalise these points, together with confirmation of clearances between the tiller boss and deck as well as the rudder blade with the bottom of the hog.

...Moving into the cockpit, the setting out of the seat risers had to be sorted. The risers run along the timbers and provide a landing for the bearers that will support the seats in the cockpit. The inner edge of the seats rests on the top of the locker fronts, the outer edge follows the line of the coaming and therefore stop some distance short of the hull planking (i.e. the width of the deck). Previously, these risers were about 3/4" by 1 1/4" deal, screwed directly onto the timbers, so that the 3/4" edge was uppermost. The riser was bent to conform to the curve of the hull, the strain being taken at the screw points in the timbers. To my way of thinking, this creates nasty point loadings to the timbers; which whilst not exactly fragile, probably do not need weakening any more than necessary.

In addition, the inner edge of the seats are also curved (outwards), so the the locker fronts too need to be pulled outwards to conform to the curve. The only way to do this is to tie them into the risers with the bearers, so there is additional strain on the riser fixings and thus the timbers.

My plan is somewhat different. I will make some hanging brackets that will be fixed to the timbers that will shaped to fit the curve of the timbers and extend to about 6" long and fixed top and bottom. 

The riser will be steam bent to conform to the curve of the hull to reduce strain on fixings and will be fixed with the 1 1/2" face uppermost. The seat bearers will be dovetailed into the riser (they are already dovetailed into the locker fronts), spreading the strain over the joint rather than a screw fixing.

The junction at the timbers is now more of a vertical shear stress against the 6" face of the bracket, rather than the single screw of the arrangement I removed. I suspect the original design was as I plan to do, otherwise why dovetail into the locker fronts? I suspect this was discarded after the first re-planking in the '80s as it was too time consuming to do properly.

The rest of the week was spent making up the brackets for the cockpit (as well as the cabin for the bunk risers).

Sunday, 10 August 2014

Other stuff

August, week 1

Not quite sure where this week went...

Anyway, spent a couple of days filling the nail holes in the ply deck skin and then sanding off, but not before the final titivation of the apparent sheerline along the top of the deck.

Saturday went to our annual pilgrimage to Hickling Broad for the old dear's birthday and managed to get a few shots of one of Corsair's sisters showing off her knickers:-

A distant cousin from the same designer:-

...and some more unrelated smut(!):-

Sunday, 3 August 2014

Deck skin finished

Week 4

Much of the week put aside to landscaping around the garden - cutting hedges that we have left for about 8 years (if my maths is right) - so that took time; one down and four to go... any way it's been too hot to epoxy really.

However, by Sunday seems I've finished the plywood skinning  of the deck:-

Not sure if it's been discussed before, but since the thought processes involved in laying this stuff - especially by the stem, I have decided not to refit the bowsprit.

I anticipate sailing this boat, most of the time, single handed and coming into moor with a 5' bowsprit sticking out the front is going to be awkward; not to mention the potential for collateral damage as a result of the significant leverage such a pole will do - and quite frankly, after 5+ years rebuilding this, the last thing I want to do is repair the bloody thing.... in any event she wasn't designed to have one; Father shoved piddly little 18" to 2' one one after quite a few years of doing without one - I don't know why and he isn't around to ask - so it stays off (for the time being....)

Sunday, 20 July 2014

Decking - Layer 2

Week 3 (delayed by yet another broadband failure from BT...)

Over the last few days, the 5mm (or is it 6mm? - can't remember) plywood has been laid over the deck planking.

A fairly time consuming task with the shape of each panel being modified until a fag-paper fit is obtained with adjacent structures. There are 14 panels to be done, for each the process is the same. First the deck planking is "wetted out" with un-thickened epoxy, followed by the plywood panel - making sure the edges are well saturated. 

Then batches of thickened epoxy are made up and spread over the wetted out deck planking with a notched scraper. Working as quickly as possible in this heat and trying to use the coolest part of the day first thing in the morning, otherwise the 1st section applied is already going off by the time you get to apply the panel. This will mean limited squeeze-out of excess epoxy, but more importantly leave voids under the ply leading to rot potential.

The ply panel is laid onto the deck and pushed home against adjacent objects i.e. cabin side or neighbouring panel. Then using the nylon brads and pneumatic nail gun, an edge is secured at about 1 to 1.5 inches intervals. Then working towards the outside edge of the deck, a grid pattern of nails at about 2" pitch are driven in, hopefully generating a wave of excess epoxy under the advancing front of secured plywood, until the edge of the boat is reached (and it oozes out all over the floor...). Hopefully this means there will be no air pockets trapped underneath and the surface will be uniform and smooth.

It is only really possible to do one panel at a time - each previous one needing to be cleaned up before the epoxy gets too hard and to making sure that a clean joint can be made between the next panel.

By the end of the week all but the 1st panel at the bow - which has a lot of curvature and is being clamped down for a couple of weeks to induce some bend and a couple of little strips by the aft sheetman's hatch, are fixed.

When these are fitted, the next task is to fair all the sunken nail heads and any undulations that may be present at the panel joints, ready for the application of the glass mat.

However, the main reason for doing this at this stage is to cut the hole for the rudder tube. This will allow me to determine the exact final depth of the tube from the underside of the hog to the top of the boss that sits on the deck and allow the fabricator of the rudder assembly to machine the bronze tiller casting I had done some months ago, so the two mate together without either binding or being too high off the deck...

Sunday, 13 July 2014

Back on Strike

July, week 2.

As I tentatively tap the crease (middle and leg) and await the deliveries of the coming weeks, a small retrospective of the the past 8 weeks or so.

It was possible to slap on a coat of varnish or 12 during the early stages of the last work intrusion and the cockpit seat locker fronts are now done and propped into their positions:

The seats were laid on top to determine position of the riser at the back, but due to replacement of the bulkhead bearer, they are now a few millimetres too long and need to be trimmed or they will scratch the varnish on the bulkheads.

Decks are in the process of being covered with the plywood substrate in advance of the final glass mat / epoxy finish. Using the pneumatic nylon brad nailer, it's a breeze. They seem to hold well, the only proviso is that the planting of a size 9 on the edges and banging in a brad every 1" is the only way of pulling down the edges. Ensuring that you kneel on the glued panel as you bang in the remaining brads means - one hopes - the panel is pulled down onto the deck planking and hopefully epoxy, without any voids and  leaving a smooth continuous surface.

The heads of the brads do bury themselves a bit, so the whole surface will need to be filled and fayed, which is a bit of a P.I.T.A. but beggars......

Monday, 19 May 2014

Topping and Tailing

Week 3.

Rushed write up before flying out to Russia again.

Major re-constructive surgery on starboard frame was completed. Some interesting experimental joints, but got there in the end.

First the end extension:

Then the more complex insertion:

When done and tidied up, a fitting session and a check to see where the seat join would be so I could remake the back pad to accept the dovetailed cross member: 

Last thing Sunday - 1st coat of varnish:

Sunday, 11 May 2014

Moving back

Week 2.

Waiting for the new bronze coach bolts to arrive for the stem, attention turned elsewhere.

Not wanting to crawl about too much in the boat without the bow props in place, decided to look at the cockpit seat locker fronts.

These are similar construction to the panelled cabin bulkhead, without the panels of course:

The above is looking toward the back - so the right hand seat is port and vice versa.

The port seat is simpler because it is a single plank; the starboard one is split 1/3 forward: 2/3 aft, this is because the forward section is hinged and lifts to gain access to the stove. At some stage the locker frame was butchered, presumably to enable some kind of door perhaps to use an oven that had once been installed. This had the effect of destroying the structural rigidity of the frame. During the process one of the staves had been shifted about a couple of inches aft. This was achieved by sawing through the tenons that secured it in the frame, and then the top rail was severed - nice....

This butchery didn't go well 

The hinged element was incorporated into the moved stave by slicing it down the middle...

This has to rectified, as does similar damage to the forward end of this section

First is the hinged stave that has to recombined and the tenons replaced and the infill dutchmen inserted to disguise the original mortice sockets removed:

The forward stave reconstructed:

Next will be the interesting insertion to replace the rotten infill piece - interesting as there is little wood to play with around the mortice of the upper stave:

Meanwhile grotty sections of the port side were replaced:

...and then the whole lot reassembled, glued and wedged:

...and finally rubbed down prior to test fitting into boat (as position of bulkheads may have moved slightly and minor adjustments necessary).

Coating the inner topsides in the cockpit with shellac was also started until I spilt half a pint of the bloody stuff all over the new red lead paint of the bilges - not happy. So that'll need a re-coat later in the coming week - leaving it to harden for a fortnight during my next Russian sojourn away starting the 3rd week of May...

Sunday, 4 May 2014

The final kick in the teeth?

May, week 1

Tubing arrived on Tuesday and after a hour or so managed to remove the four bolts holding the stem to the solepiece. 

And here's the boot; the aft most bolt hole (right next to the joint with the hog) is really, really bad. A lot needed to be chopped out to get back to anything with guts, nearly up to the edge of the garboard (not good). Further excavation revealed the the core of the stem is effectively buggered. I cut a central section out right up to the underside of the solepiece at least 3 inches long and over an inch wide. Even then the whole lot was so "iron sick" it crumbles with little effort.

The stem is the very last thing one ever wants to replace in a boat - it's akin to a triple heart/lung/liver transplant. 

All the planks I did last year would need to be sprung and released for about 4-5 foot back from the stem, the deck probably too. The old stem removed and a replica made, copying exactly the rebate and bevels of the old one. Inserted back into the boat, all the bedding paint and varnish scraped from the lands of the planks, new stuff applied and then refastened (with fasteners one size larger).

Sod it.

This is the first time I am going to bodge anything on this rebuild.

I will patch the stem and hope to get 10 years out of it.

Before digging as much as I dare, the cavern reveals itself:

First the shape of the larger dutchman is traced on the stem:

Cutting this out with an angle grinder, plane and chisel, the Mariana Trench is excavated for the "deep dutchman", which is fitted and epoxied in:

This is trimmed back and the aperture for the larger dutchman cleaned up and the new piece is made up ad dry fitted:

Before this can be epoxied the, bolt holes in the stem need to be plugged as well as any other old screw holes:

These were then  tidied and the dutchman epoxied in place - held by spreader clamps pushing upwards.

When cured it was tidied as others have been, ready for the bolt holes to be drilled through:

Sunday, 27 April 2014

Still tidying

Week 4

Still messing about tidying up bits and pieces left behind so:

Fitted a wedge or two to the forward-most floor up in the forepeak an shoved in a couple of screws and a rivet

The 32mm auger bit arrived, allowing me to counter bore the tabernacle seat to accept the washer and nut for the floor bolt. As with the transom bolts, there was a lot of damage at the head end, so this was bunged and counter-bored also:-

Finished the transom knee, bolted through the hog and screwed through the transom (having first wrapped some caulking cotton and mastic round the underside of the head).

Continued with the stem repair by trimming off the dowels plugged in last week. 

Glued in thin wedges to back out the rebates cut for the old bobstay fitting. These could have been tricky if it hadn't been for the new toy, so nailed them in place with nylon brads whilst the epoxy cured. These were then trimmed.

The arduous task of cutting the shaped dutchman for the stem infill took about an hour, eventually this was stuck in with G-flex (special epoxy for Oak). This is damned expensive, but as there wouldn't be any permanent fixings, I don't want this to fail. Two nylon brads shot in top and bottom and left overnight. 

The following day it was cured and half an hour or so later with a plane and spokeshave resulted in this:

In gaining better access to the stem, I had removed the brass keel strip, noting the cracks in the lower section of the stem. No problem, we'll give them the same treatment...

A quick wazz with the angle grinder and - odd..... these are lumps of iron....

The penny drops, these are the heads of the bolts attaching the stem to the apron - or more accurately perhaps, the solepiece (inside). 108 years have take their toll; they're expanding as they rust, splitting the wood. Get 'em out.

1.5 hours later no dice; the bolt is compacting in the hole, so the shaft has clearly waisted and is now buckling under the pounding, also the head outside is deforming during the attempts to loosen and eventually snaps off during attempts to straighten. Bugger.

I thought I'd left all the structural stuff behind....

Off to the pub (Ramsholt Inn on the Deben - bit of a trek but worth it) for a pint and think. Back home a lengthy search on eBay and I can get 1.4" and 3/8" O.D. Stainless tube with 22 S.W.G. (0.7mm) walls. The bolts are 1/4". 

The idea is to cut a six inch length of tube, cut some teeth into one end, mount it into a drill and use it as a hole borer. It should just slide over the bolt from the inside and I can core out the bloody thing and replace with either an oversize bronze coach bolt or plug the holes and use a 1/4" (a bit like an oversized version of this). We await the arrival of the tube to see if it works. My only fear is that the walls may be too thin.

Other little jobs included the red leading of the bilges in the cockpit; usual treatment - 1st coat 50/50 preservative / red lead (plus a dash of driers); 2nd coat 15/85 turpentine / red lead (plus a dash of driers)