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)

Sunday, 20 April 2014

Bits and pieces

Week 3.

Waiting to continue with the decking, there were a number of odd jobs that slipped through the net over the last couple of years; so whilst waiting for stuff to be delivered over the Easter break, a number of these were knocked off:-

Tabernacle seat fitted late last year needed the bolt hole from the forward floor extended through it. this was bored with a brace and bit until the pilot screw just penetrated, then realised I needed to recess the nut and washer so stopped just in time. The small exit hole left by the pilot screw will centre the counter bore for the washer nicely - provided it isn't too big. However I don't have a 32mm bit so another delay whilst that arrives.

Transom knee needs fitting, but the recesses in the hog are worn, too big and too deep. These needed to be plugged with new timber, so a quick overbore and plug of Doug Fir was epoxied into place. When cured it was tidied, smaller bores cut ready for the new bronze coach screws. The knee (which is being varnished) will be bolted in place later in the week.

Moving forward, previous fittings (at least two generations) for the bobstay anchor needed to be rectified. The oldest were two serious holes in the front face of the stem at water level. These were bored out with 16mm bit and a cross grain dowel cut on the lathe. The natural way to cut a dowel is with the end grain in cross section, this one needed the grain running along the cross section. This makes it more fragile during the turning process on the lathe, but its swelling characteristics when wet hopefully will be  the same as the stem. A traditional dowel could swell more and could split the stem where it becomes narrower.

When the epoxy has cured these will be trimmed and the leading face cut back to accept a graving piece as well a couple slivers to fill the graduated rebate seen in the photo above. Al  will then be tidied up and eventually invisible under the white paint of the boot-top line.

How the bobstay will be anchored in the future is another problem - I feel maybe another casting coming on.....

Sunday, 13 April 2014

Thinking ahead

Week 2.

Whilst waiting for the compressor to arrive, moved on with another nagging thought.

With all the screws holding down the sub deck (which will be covered with the ply and eventual fibreglass), the last thing I want to do when all this is finished is fix fittings to the deck and strike a hidden screw. I need a map of screw heads that accurately shows their positions.

Initial thought was of a photo montage with measurements written on it. The problem with this is where do you make the reference point(s) from which all measurements stem - there are few straight edges or right angles...

It was whilst laying out the templates on the ply, the brainwave struck - make duplicate templates out of clear polythene. Sadly the brainwave didn't continue, as I decided to take the original paper template to the boat, lay drawing pins over the screw heads, place the paper template over the points, press down to prick the paper. Removing the paper, punch holes to enlarge the pricks, lay over polythene and trace the outline and hole locations - great in principle. 

It wasn't until I'd done all this for the 1st one that I realised polythene was transparent - all I needed to do was lay the damned stuff over the deck and draw the bloody screw heads on....... Tunnel vision again; a recurring fault of mine.

The plywood panels were cut out. Extreme care was taken because this is Bruynzeel ply - 20 year guarantee and about £65 a sheet and difficult to get hold of...

The two complicated ply panels that wrap round the tabernacle were fitted and operations halted whilst I wait for some notched epoxy spreaders to arrive.

Friday, 11 April 2014

Back on yer heads...

April, week 1.

Making templates this week for the plywood deck, hopefully as per the plan conceived in October. Using reel of 4' wide paper. The local print works discards the last 10 yd or so of an old reel at change-over; fortunately it's the same width as a sheet of ply....

Laying over the deck and creasing over edges, it's quite easy to form a template which are then cut out to lay over the sheets of ply.

A slight deviation from the plan for the side decks; originally I planned 8' lengths, but by mistake / accident / subconscious inspiration, did 4' lengths. This means less is lost accommodating the curve of the cabin side over a 4' length than an 8' length:

Both side decks come out of one sheet - which is nice.

All other templates fit exactly as planned (barely disguised smugness...)

Earlier during the week, after 6 months pondering, made the decision to go plastic. The ply needs to be epoxied to the sub-deck and fixed. It was a toss up between screws or nylon brads. Screws are simple, but require removal and subsequent hole repair. In addition you need to be absolutely sure there are no voids left in this filling process to avoid future  rot possibilities.

Nylon brads are fire-and-forget; they don't rust, sod up planes or other edged tools and don't need to be removed - but they need a special pneumatic nail gun (which I don't have) and cost an arm and a leg. 

I now walk with a limp.

Awaiting delivery of newer compressor to use gun now...