Restoration of 25ft Motor Cutter - 5

 Work to repair the keel involved cutting a new scarf on the forward end of the keel which had been lopped off by the original repairers. We had previously driven out and removed the four 5/8" copper rivets that held the forward lifting eye plate but there remained a 3/8" copper keelbolt through the section in which we were to cut the scarf.  There is a bolt like this every 6-7" throughout the length of the keel.

Keel bolt being driven out. Line of scarf marked on keel timber.

The scarf line was marked on the keel and using a power reciprocating saw (which was a Godsend as the timber is very, very hard) the scarf was cut to near the line.

Sawing along the line of the scarf

We attempted to rasp, chisel or plane the scarf but lying on one's back under the boat coupled with the hardness of the wood made this a very difficult task. We opted for the router solution and carefully made and clamped a guide ramp to the keel and ran the router fitted with an end mill over it.

Router guide clamped to keel

Cleaning up the face of the scarf didn't take long

The scarf was given a final clean up with the chisel.

Completed scarf. The holes are the lifting eye-plate bolts

The shape of the keel repair piece was marked onto our new length of timber and it was sawn and planed on the bench till a good close fit was obtained. This took time.

Cutting and fitting the new timber section

Checking the new section for closeness of fit.

The forward scarf had an existing stopwater tight in the joint between forefoot and hog underside and the new timber's scarf was cut to match this. The sides were carefully planed to give a seam for caulking and it was made to fit snugly up to the underside of the hog.

Next job will be to drill new keelbolt holes and bed this in and fasten. I've got some bronze rod, nuts and washers on order - eye-wateringly expensive!

Motor Cutter Restoration - 4 Work continues

 Work on the boat slowed somewhat during the lockdown as I was only able to visit the boat occasionally on my way home from work. My buddy, Pete, was unable to work with me. However I was able to clean down her bottom and get some primer on to slow her opening up as the weather became warm and dry in April.

Underwater primer going on

A couple of coats of primer on the bottom

Another job I tackled was to find a coupling to fit the propeller shaft that would match the output flange of the Dorman's gearbox. Nothing was available off the shelf so I drew a dimensioned diagram of the coupling to suit the 12:1 shaft taper and keyway and had it made by a specialist. Not cheap but it is an excellent job. The Cutter has 1 1/8" diameter tail shaft which is a non-standard size these days and I was warned that if a new shaft was required it would have to be specially ground. Fortunately the shafting is in good condition with very little wear, straight and no damage.

Custom-made prop shaft coupling

Perfect fit on gearbox...

...and shaft taper.

Various small holes in the hull were plugged and repaired..

This was were the engine intake seacock had been moved to.
All these holes were plugged and a tingle glued on the inboard side.

Nasty holes and damage caused by a sacrificial anode mounting studs

Holes cleaned out and iroko plugs glued in place - grain orientated in line with plank's.

Fortunately the boat's original seacock had survived and it was carefully dismantled and cleaned. Its original location and part of a bronze adaptor plate still existed, although plugged and covered with a wooden tingle.  This was removed and the fastening holes opened up again since I'm going to re-install the seacock in its original location as per the plans, since it will be adjacent to the engine's pump intake.

Seacock checked and cleaned - a lovely bronze fitting.

Original seacock location

Part of one of the mounting plates; holes line up exactly.

Some small repairs were done to the engine beds; removal of studs from a former engine installation and filling of holes. Loose paint was stripped from the area around where the engine sits and also in the stern sheets under the thwarts. Primer was applied followed by bilge paint and white undercoat.

Bilges under engine cleaned and primed

Loose paint - lots of it - stripped in stern sheets

... and primer applied.

Repaired frames primed

Bilges given a coat of grey bilge paint. Orange glow caused by sunlight shining through the cover.

The midships bulkhead was sealed and fastened into place and the thwart screwed down tight on top. The knees were then nailed and riveted - these used 6-gauge copper nails up to 6" long with 3/4" roves to suit.

Bulkhead finally fitted and fastened

Knees being fastened

Midships and forward thwarts fastened

These stiffen the boat up considerably

We were itching to have a 'play' with the engine - one of two that I have. The first is complete but the second has been partially dismantled - goodness knows why!?

It was over a year since the engine last ran so we removed the rocker cover, checked the tappet clearance and poured plenty of oil over the valve gear and cranked the engine over by hand. A fuel supply was rigged up, battery and starter button connected and after some bleeding of pump and injector lines she started and ran..

Checking valve gear

Fuel and cooling water hooked-up

It lives!!

I have made some threaded adapters that have allowed me to install some more modern glow-plugs to aid starting. The originals were low voltage series-connected but I've fitted some from a Land Rover diesel that work really well.

There are a few jobs to do to the engine before it can be installed: It needs a dynamo or alternator to be driven from the 'Vee' pulley on the side of the engine, speed control and linkage and a control panel to mount gauges and switches.

In the meantime we cleaned the engine, primed it with red-oxide and enamelled it in a more appropriate grey that may approximate the colour it originally wore in service.

Cleaned and de-greased

Red oxide on

Two coats of grey enamel...

..and black fitments.

There are lots of parts on the Dorman that can be polished.

Back to the Cutter we investigated the suspicious steel 'shoe' that encased the forward part of her keel. It was bursting with rust and so the remains of bolts were cut off and driven out and the thing was sliced and prised-off.

Underneath was a tidy piece of oak that had been slotted-in forward of the lifting plate and scarfed to match the original stem piece. The after scarf was too short and was obviously weak so we drove out the four heavy copper rivets holding the lifting plate to enable a long scarf to be cut. 

Cutting away at the steel 'shoe'.

Peeling it away

Freeing the forward keel section

Cutting the lifting plate fastenings

..and driving them out.

Restoration of 25ft Motor Cutter - 3

With the frame repairs completed we turned our attention to replacing and strengthening the thwarts.
The Cutter has five transverse thwarts and would have originally had side benches linking them all from bow to stern and in each after quarter there would have been a small locker on each side.
Firstly it was decided to renew the thwarts which are currently softwood that is too narrow but excessively thick.

Some suitable Utile was obtained and machined to the required section of 10" by 1 1/8".

I started with the forward thwart and my buddy worked on the sternsheets where the seating is double-width.

New forward thwart takes shape

After thwart - took a lot of measuring and cutting to get it to fit

Second half of after thwart

Second thwart - knees are expoxied plywood

Then we made the forward and midships thwarts and a start was made on building a new bulkhead in the original midships position. On the plans this is shown as being watertight and as the boat's bilge would have been in two sections there is a second drain plug immediately forward of the bulkhead. To simplify things - and to negate the need for two bilge pumps - I elected to cut limber holes in the bulkhead to allow drainage.  If absolute originality is required these could be plugged.

Midships bulkhead being assembled - joints are half-lap and will be glued and nailed

Another job that was carried out now was the strengthening of her sternpost.  During a conversion into some form of cabin cruiser they cut a slot in the transom to install a tiller for wheel steering via wires and sheaves. This slot had cut right through the sternpost weakening the upper part of her transom.  As the sternpost is otherwise in good condition we decided to fit doublers to it and fill in the gap; not pretty but it gives the transom some strength back.

Sternpost with doublers fitted

Restoration of 25ft Motor Cutter - 2

The Motor Cutter has these identification markings carved into her hull. They appear to be boat number, length, date, and presumably a dockyard i.d. mark. They are carved into the starboard side of the stem post and on the inside face of her transom. The transom markings will still be visible between the aft quarter lockers built into the sternsheets.

Carved details on stem

On inside face of transom.

Restoration of 25ft Motor Cutter - 1

An initial assessment of the boat showed that she had fractured timbers (ribs) along both sides roughly at the turn of the bilge where the heavy floor timbers end. These are 3/4” by 1” with a radiused inner face. The timber appears to be Canadian Rock Elm but unavailability of this meant that I sought some unseasoned English Oak and a source of this was found nearby.

Radiusing the new frames

The oak boards were sawn down, planed and had the radius routered on.  They needed about forty minutes in the steamer before being bent in. We clamped and wedged the replacement frames alongside their broken originals and left them until the following weekend.

New frames temporarily clamped into place

A section of each broken frame was marked and fastenings cut off and driven-out before the section was cut away using the 'multi-tool' and a scarf made on the remainder.  Each new frame was scarfed to fit. Then when ready the scarfs were glued and the frames re-fastened using the original nail holes. As she is planked in hard wood I kept to the original 10-gauge nail.

Marking a frame for cutting

'Multi-tool' was a great help in the confined space

Checking new frame section for scarf fit.

Scarfs glued and re-fastened

Whilst this work was going on I was also stripping the paint off her bottom. A filthy horrible job since she had been tarred to preserve her by a previous owner. Badly neglected there must have been some areas that had been bare for a while and there is abrasion and barnacle marking here and there. Stripping also revealed that she has had planking repairs carried out in the past; starboard side amidships; port quarter and by her stem on starboard side.

Stripping her bottom paint

We also started plugging some of the holes left by removed skin fittings - and there are several all over the hull.  Here my buddy is filling up where a massive exhaust outlet was once installed in her transom. Left over from a now-removed engine.

Plugging holes with glued iroko

I have been fortunate in being able to obtain an original engine for the boat of Dorman-Ricardo type 2DSM that this boat almost certainly was fitted with when originally built (plus another spare one!). Here is a page from the engine manual showing the installation in a 25ft Cutter:

Dorman 2DSM installation drawing from the engine manual