Saturday, 19 November 2011

Stern Stuffing Gland

With the engine out I was able finally at last able to get clear access to the stuffing gland for the prop shaft. I posted pictures on my main website ages ago when I was trying to identify the gland type.

The area was cleaned using dishwasher detergent to break down all of the old oil, grease and smells and did a great job as you can see. I uses a toilet brush (NEW!) to get into all the nooks and hard to reach places, and was topped off with a gentle rinse from a jet washer.

With help of Practical Boat Owner forumites and Cox Engineering we figured it out.

EDIT 14/03/2012

I finally got round to removing the whole of the tube and bearings. It was a Stuart Turner type glassed in at the inboard end so was not serviceable. It uses white metal bears that have to be lathed out, and then recast and turned! I will be replacing with GRP tube and composite bearings at the outboard end. It will be a water-cooled PSS shaft seal at the inboard end.

Here are the before and after photos!

Before steam jet washing!

After dish-washer detergent and Jet-washing!

Engine Removal

This covers the removal (more like extraction!) of the old Yanmar YSB12 from my Snapdragon 27. I have no idea how long the engine had been in there, the bolts where rusted in deep! I visited the boat every evening for a few days to soak the engine mounting bolts/brackets and ancillary equipment connections in Plusgas penetrating oil. Two of the bolts came out easy but typically the last rear bolts didn’t want to shift even with the biggest socket wrench I own, a pair of stilsons, and liberal application of heat. In the end I ground off the head of the bolts, but this lead to problems later on sliding the engine out. 

Engine Before Removal
To slide the engine out I had to place a small bottle jack under the engine to raise the brackets off the bolt stubs; I also had to remove the alternator so the engine would leave the enclosure.

Lifting out the Yanmar YSB12

I lifted out the engine using a forklift with extension forks so that I could get them centred over the top of the engine. I lifted the engine using chain and hooks through the engine lifting eye bolt. You can see my wonderful helper for the weekend ‘Mike’ whom was repaid with the promise of a sailing trip and a few beers. 

Engine Out! Huzzah!

Extracting the engine from the engine bay was a bit tricky, I am glad I had my helper for the day doing various twisting and manoeuvring whilst I worked the folklift.

End of a hard days work!

We got the engine onto a pallet and stored in my workshop. The engine still starts and runs; I am not sure what I am going to do with it yet. I may offer it up for sale, or I may take the time to freshen it up and put it into a project next year. 

I have been looking at replacement engines and speaking to manufactures and owners and I have decided the way forward will be with a Beta 20.


Sorry I have not updated the site for a while! My laptop suffered a catastrophic hard disc failure due to the main fan failing and the whole insides cooking; Fan now replaced, new hard disk installed and 118gb forensically restored from the old HDD block by block… it was like taping back together a phonebook that had been through a crosscut shredder! I did have two back-up too and although when browsing and verifying them they were ok, extracting them was a different story!

I am working on some new articles which will be uploaded over the next week:

·         Antifoul Removal
·         Engine Removal
·         Bilge Cleaning Products
·         Window / Portlight Replacement

Wednesday, 28 September 2011

Southampton Boat Show 2011


I attended Southampton Boat Show at the weekend after finding a local coach trip organised by Woodrolfe Brokerage at Tollesbury Marina in Essex.

  • Attending MCA presentation on Safety Communications devices including best practice using: EPRIB, DSC VHF, AIS, Navtex, MOD Devices, Satellite Phones, and CG66 Registration

I was sadly disappointed in some retailers at the show, perhaps being my youthful appearance and not wearing an expensive suit. One retailer in particular a blue Kubota based marine engine manufacturer whose sales reps were complaining about a customer who wanted to install a engine himself and the low profit of a sale so they wanted him to go elsewhere to save on paperwork; as this is what I am planning on doing I gave them a wide berth and continued onwards

I strongly recommend CG66 Registration. It is a FREE service provided by the UK Maritime and Coastguard Agency which allows boat owners to register their vessel, including contact details and next of kin. 

MCA Presentation
The show was quite busy, though as I have never attended before can not compare it to previous years; Reports were that is was 9% down on last year. The food was quite expensive from the onsite vendors: £6 for a burger and £4 for a beer, I was very glad I took a pack lunch!

Beta 20 Engine

Yachting Monthly - Crash Test Boat

HMS Bulwark

Some of the boats on show

Tuesday, 6 September 2011

Stripping (Not me! The boat!)

Greetings web fans and those interest in the Snapdragon 27 Yacht.

I spent Sunday in the shed taking measurements and stripping of more deck items; rails, pushpits, pulpit, and some of the items in the locker.

I found a rather dangerous bodged bilge pump pipe. It had a Y splitter in it and one of the inputs had just been blocked with a rag held by a jubilee clip!!! Imagine if I was taking on  water and tried to empty the bilges with the incoming water just going in circles!

I also removed the existing side loading gas locker. The drain for the gas was not all downhill. The pipe had a slight loop in it as you can see in the photo which would hold gas! I am going to build a new gas locker to current regulations.

If you are following with interest regarding Antifoul stripping methods I have received a tin from International last week kindly donated by them to help with my studies. I hope to do the test in two weekends time when i have both the Saturday and Sunday free.

I'm trying to integrate this blog with my one on the main project site at so that I have to write the blog once and not have to cut and paste it between the two

Sat in the starboard locker unbolting the Pushpit
RATHER DANGEROUS! The bilge pump had a Y connection in it and this is how one hose had been filled!

Old Diesel Tank and Side loading gas locker.
Exhaust Output to Stern
Deck Stripping Underway

Thursday, 25 August 2011

Please see attached two pictures from my Snapdragon 27 MKII. She is a single Keel Model

The actual waterline is really quite low. The green line in the drawing shows where the gelcoat of the hull changes from Blue for the Topside, to White for the under water area. The first 2" is painted white for the boot-top, and remaining underwater area in blue anti-fowl. I will take a picture showing where I have stripped the anti-fowl and boot top to see what was underneath.

The boot top at the bow is approximately 4-6" above the actual waterline, and about 1-2" at the transom.

A previous owner contacted me through my website to say he thought she was underweight by the way she was performing, and during the complete rebuild I have found bags of sand and stone in the bilges.

The keel is encapsulated. I got my head down into the bilges to see if I could see the top of the keel to see what it contains but it is well sealed. The only way I can think of getting in there is major surgery through the side of the keel or through the cabin floor.

I measured in the barn this afternoon... The waterline is 5" lower than it should be half way along the hull... oh dear.

Wednesday, 24 August 2011

Antifoul Removal Products Undertest

International Paints have kindly offered to send me a sample of Interstrip AF:

Cirrus Systems Ltd have agreed to send me a sample of their RemovALL 620 product, which is biodegradable and non-toxic:

My gratitude goes to both of theses companies for helping me in my studies and being able to give me first hand experience of their products.

I am still waiting to hear back from Owatrol to see if they would be willing to provide any of their products for testing.

I have decided not to use Hempel's product as unlike the others it does not claim to be safe on glassfibre and gelcoat "Use with caution on glassfibre and plastics (may harm some thermoplasts)" so I would would rather not take the risk on my precious hull.

Monday, 22 August 2011

Anti-Foul Removal

Sorry it has been a long while! It has been the summer holiday here and I started a new job which I have been getting settled into.

I have started to remove the anti-foul from the hull of my Snapdragon 27 MKII and thought I would document the results here.

The first method I am trying is the Proscraper by It has a vacuum attachment to collect the scrapings which is quite useful to keep the workshop floor clean. Sarah struggles a bit with it, it requires quite a bit of force from one hand pushing down whilst pulling with the other. I can work with it quite quickly stripping paint and primer down the bare gelcoat, but it gets tiring quite quickly.

It has gouged the hull quite badly in some areas where the hull is rounded and have rounded of the edges of the blade with a metal file to try to prevent this further.

I am going to upload a photo of the area on the skeg where anti-foul has been removed.

I am going to try and get samples for some chemical gelcoat safe anti-fowl removal products and will update my progress here. I am hoping this research will help with my Yacht and Small Craft Surveying qualification which I am currently studying.

Friday, 10 June 2011

Beale Park Boat Show and Injury

Beale Park Boat Show starts tomorrow in Essex, England. It's not too far from home but I ruptured my quad muscle in me knee today (OUCH) and the Emergency room has put me on crutches and pain killers after a ultrasound. I'm not to put any weight on my leg for at least a week. I am hoping a family member will loan me a wheelchair so that I can be pushed about for the day.

Would be great to meet some fellow local boaties, and see some of the new toys available, also to raid the boat jumbles. It might also help if I can do some research for my degree's by looking at some new boat designs.

Mast Removal

Bit of a late update but I removed the mast which had been stepped on my Snapdragon 27 yacht Ardtalla last week; it has been sitting on the deck since I moved the yacht last month.

With a bit of grunt between two of us, and the saloon cushions as landing mats we managed to get the mast down in about an hour and a half all in once piece with no breakages. We cable tied up all the running and standing rigging ready for attention at a later date.

I am going to strip the mast down, renew a lot of the components and electronic. All of the running rigging is going to be replaced. The bulbs are going to be replaced with low wattage LED equilivlants.

No the mast is off the next step is to remove all of the deck fittings, hatches and windows; ready for renewal, repair, re-bedding.

Watch this space!

 Getting Ready

 Starting to tilt the mast back

Ready to drop

Foam/Boxes on standby to catch the mast

Mast Down!

Wednesday, 11 May 2011

Custom Boat Cradle

I designed a new boat cradle with castors for my boat so I could get here in and out of the barn easily once she was in her new home.

It is made from 100 x 50 mm square hollow steel tube, MIG welded together and painted with Red oxide. Each castor can hold 850kg bought from RS components.

It also has a tow bar hitch connection so I can use my car or forklift to move the cradle about.

Boat Moved

13th April my Snapdragon 27 Yacht was moved by road. I used D&D Transport based in Ardleigh, near Colchester, Essex, UK

All went well, though it took a few attempts to get the yacht sit sit properly in the new castor fitted yacht cradle. The yacht was not in the boat yard slings quite square, so when her keel weight was in the cradle she kept twisting slightly. Using brute strength of four men and a bit of rope we got it squared up.

The journey was about 35 miles and took about an hour. We went slowly to avoid the rock bouncing about too much on the giant truck; which was 60ft long and had a 65 tonne crane! We got her to her new farmyard home and got her unloaded from the crane. I used the towball on my car to position the cradle in the barn (Ardtalla's new home for the next year).

Just before the move


I have been away from the boat and site for a while.

I have been studying hard, and went on vacation to Barcelona. I of course checked out Barcelona Marina to check on the yachts there!

I'm getting the boat moved so it is a bit closer to me, and therefore have more time to work on her. This will save me two hours of travel and heaps of petrol money! It's taken me weeks to find a friendly farmer with a spare barn, and a lorry with a Hi-AB crane that won't charge stupid amounts of money. I have also been designing a new yacht cradle that I can fit castors to so I can get in in and out of the barn as needs be.

Design Stages (Sketch-up)

New Book

Currently reading this book 'This Old Boat Second Edition) by Don Casey. I'm finding that it has lots of information and ideas that I would have never came up with. It is helping planning the project and what to expect and budget for.

As Bought

Photos of my Snapdragon 27 Yacht when i bought her in August 2010.

She looks very different now! All the insides have been gutted out and she is sitting in a barn I am renting.


Welcome To Goodtarp.Com

Welcome to My own little place on the internet.

This site will track my progress on refitting a Snapdragon 27, from the big monotonous jobs, to the little annoying ones. I hope this site will help fellow Snapdragon owners, and give a chance to brainstorm with other boat owners with similar size vessels.

I bought my Snapdragon in August 2010 after searching for 5 months for a suitable DIY project. It is my aim to fit the vessel to make it habitable as a liveaboard and eventually as a long distance blue water cruiser for travel to Australia via the Atlantic and Pacific oceans. I am studying two part time degrees at the moment with Westlawn and MPI. Small Ship/Yacht Design, and Marine Surveying.

Yanmar YSE YSB YSM 8 12 Engine

My Snapdragon 27 Yacht is fitted with a Yanmar YSE12 Engine. This is very similar to the Yanmar YSM, YSE8, YSB8, YSB12 Engine.

I am going to rebuild the engine and will document the process on this website.

The 'E', 'B', 'M' I believe stand for 'Early' 'Between' 'Modern' versions of the engine. The YSE & YSB are very similar, with the YSM having a different design and ancillaries. The main difference I have noticed on the YSE and YSB is the thermostat housing or 'Water jacket', on the top of the engine. There is an identifying plate on top of the flywheel housing.

Originally designed as a flat twin, made by Coventry Climax in the mid 1930s; designed to go in the stern of landing craft, these engines were made so servicing could be from the front, the engines low height allowing them to be tucked away in the stern. Yanmar made the modified design for a single in 1974, making the YSE from 1974 to 1977. Modifications were made for the YSB for 1 year, before a redesign, including a different fuel injection pump for the production of the YSM from 1978 until ceasing production in 1980.
The YSE & B have a fuel injection pump bolted onto the front of the engine, while the YSM has a different type of pump, which is bolted in the cylinder block. Another difference is the front pulley is on a layshaft on the YSE & B, only being on the crankshaft on the YSM.
The engine is raw water cooled only, so operates at a low temperature. The engine should not be run slowly for long periods; the manual states to run flat out for an hour after trawling for a few hours. The oil level can be critical, as reports of oil blow by causing the engine to race out of control seem common. This is when the engine runs on it's own lubricating oil, instead of the diesel fuel.

The engine has no oil filter, relying on an oil strainer. This consists of a series of thin rings on a shaft that is turned by a T handle on the front of the engine. Thin plates between the rings; scrape the debris from the oil. The dipstick is on the oil filler, both for the engine and gearbox. Levels should be taken with the screw filler caps resting on the threads, not screwed in. Care should be taken however, as the engines are not always mounted level in the boat.

The manual states 30sae oil, but multigrade oil can be used, as this oil is superior, and was not around when the engine was manufactured. Care should be taken to only use a mineral oil, and not one of the synthetic, or semi-synthetic oils around today. These can damage the bearings of older engines.
The YSE and B have a poorly designed govenor. A needle valve in the pump releases the injection pressure, hence only about 1/3 of a turn of a fine threaded bolt is required from full throttle to stop. After all these years, the needle valve seats are worn in the pumps, causing erratic running, stopping, and poor starting. New needle valves are readily available though.

The gearbox of the YSEs can be 2 to 1 or 3 to 1 reduction (3 to 1 has a 'G' designation at the end of the engines model number of chasis plate). The reverse is very slightly lower geared, but on mine with 2 to 1 gearing, there is little noticeable difference in engine speed. The engines maximum speed is specified as3000 rpm.

The engine is noisy engine, however it is economical, using approx. 1 to 1 1/2 litres of diesel an hour.
Despite their age, parts are still readily available for these engines, although the cost of repair is becoming uneconomic in some cases, according to some people I have been in contact with.

The majority of this information came from:

Snapdragon / Mirage History

Historical Information

1959 Thames Structural Plastics formed in Rayleigh, England.
1962 Thames Structural Plastics moved to Southend, England. First sailing cruiser launched 'Snapdragon 23' centre-boarder.
1964 Thames Structural Plastics moved to Canvey Island, England. Factory becomes larger and company changes to 'Thames Marine'.
1968 'Snapdragon 21' and 'Snapdragon 29' launched.
'Snapdragon 29' is later modified and renamed 'Snapdragon 890'
1968-1974 Snapdragons 600, 670, 24, 26, 27 are launched.
License given to 'Isles of Norbury' to build and sell 'Snapdragon 670' marketed as "Invader".
1975-1980 Mirages 27, 28, 29, 30 and 37 launched.
1981 Thames Marine stops manufacturing. Marketing and Distribution taken over by ' Maplin Marine'.
Maplin Marine stops trading after twelve months.
'Boating Scene' takes over Mirages and Snapdragon 890's.
Historical Information obtained from Snapdragon Mirage Association

The Boat

Snapdragon 27

ARDTALLA / ARDTELLA, and before that acording to the Particulars of Ship Stations she was 'Columba'.
(When researching the boat, I have found 'Ardtalla' to be spelt either of the ways above)
I will be renaming her next year when she gets a fresh coat of paint, and in a nice time hounoured renaming ceremony.
Did you used to own this boat? If so I would be very interested to hear from you, and learn a lot more about her history, where she has been etc. Please use the 'Contact Me' page.

Primary Information

Model: Snapdragon 27
Built By: Thames Marine
Hull Type: GRP
Construction Year Believed 1974 - 1982 - Home Completed
LOA: 27'2" (8.28m)
LWL: 22'9"  (6.93m)
Beam: 8'6" (2.59m)
Draft: 4'6"9 (1.37m)
Engine: Inboard Yanmar YSE12 Diesel 12bhp
Berths: 5/6
Keel: Encapsulated Long Fin Keel
Rig: Bermudan Mast Head Sloop
Displacment: 5500lbs (2495kg)
Headroom: 6' (1.83m)
A PDF is attached below which gives the standard spec and layout for a Snapdragon 27.

Standing Rigging:

Location Type Circ (") Circ (mm) Dia (mm) Length ' Length " Length M
Forestay 1x19 SS  3/4 19 6 33'5.1/2" 401.50 10.20
Backstay 1x19 SS  5/8 16 5 37'0.1/4" 444.25 11.28
Main Shrouds 1x19 SS  5/8 16 5 32'8.1/4" 392.25 9.96
Lower Fore Shrouds 1x19 SS  5/8 16 5 17'1" 205.00 5.21
Lower Aft Shrouds 1x19 SS  5/8 16 5 16 192.00 4.88

Running Rigging:

Location Type Circ (") Circ (mm) Dia (mm) Length ' Length " Length M
Main Halyard 3 Strand Prestreched 1 1/4 32 10 63'1.1/4" 757.25 19.23
Jib Halyard 3 Strand Prestreched 1 1/4 32 10 63'1.1/4" 757.25 19.23
Mainsheet Plaited Terylene (polyester) 1 1/4 32 10 50 600.00 15.24
Jib Sheets Plaited Terylene (polyester) 1 1/4 32 10 60 720.00 18.29
Genoa Sheets Plaited Terylene (polyester) 1 1/4 32 10 57 684.00 17.37
Storm Jib Sheets Plaited Terylene (polyester) 1 1/4 32 10 47 564.00 14.33
Spinaker Halyard 3 Strand Prestreched 1 1/4 32 10 63.00 756.00 19.20
Spinaker Sheets, ea Plaited Terylene (polyester) 1 1/4 32 10 33 396.00 10.06
Spinaker up/down haul 3 Strand Prestreched  7/8 22 7 38 456.00 11.58
Topping Lift 3 Strand Prestreched  7/8 22 7 63 756.00 19.20
Trackside Outhaul 3 Strand Prestreched 1    25 8 4 48.00 1.22


All Equipment is Currently Removed For Refit.

Snapdragon 27 Specifications