Saturday 13 August 2011

More rigging matters

New ideas in rigging terminal ends are slow to happen,often its just a change to a design trend already in existance but I think Gibbs T Ball was a first,its a favourite of mine,super strong and very easy to remove the rigging stay at the mast end with out tools.



The T Ball end came out some years back now,it requires a swage tool and locks into a cast 316 stainless steel backing plate that is fitted inside a slot in the masts side wall,the plate is held inplace with  monel rivets,when the T Ball end is then installed,it anchors the plate and itself to the mast,simple but secure.It also allows movement,which lines the stay up to the lower rigging screw or turn buckles prefectly.



Also made by Gibb,a super slim rigging screw,this size will suit a set of lower shrouds or stays on a yacht around 37ft long ( 12meters) the style is elegant but when final tightening of the screw was being made it tended to open out in the center slot some.With a Gibb T Ball at the mast end and a Gibb rigging screw at the deck level this was a very neat set of fittings,circa 1980 I would guess?

R McB

Friday 12 August 2011

A new design we can offer

This is another world first,its still in concept and none have yet to be built,you can follow progress here from time to time.The boat is made into a female mould we supply the build jigs to,so you build it the right way up,with drop keel this design can be moved to your sailing water and then back home.


Introducing the Owe 25

This is the designers introduction.

We are a company located in Italy, we are currently searching for distributors for our racing sailboats kits. We can provide a detailed engineering service and can provide cnc patterns for wood and all steel part ( keel, chainplates, etc..)

All our design contains Cfd ( computational fluid dynamics) analysis, structure analysis, and polar diagram made with wolfson unit vpp, with data coming from cfd studies.



we are going to end a plan for a light and high performance 25 ft.
It's build with plywood, plywood sandwic( okume/pvc/okume) and strip planking.
very light, stiff and fast. The parts are optimized with snap joints for ease of assembly.

Best regards,

Francesco Belvisi yacht design

Ceo Yam Srl

http://www.maribelle.it/

Check out the web site

R McB


Inside Killarney Race Circuit

We will be testing the Imp here one of these days,so I had better have a good look at this board before heading out.

How to clean stainless steel with Oxalic Acid

A boats 316 stainless steel still picks up dirt in the air that can stick to its surface and rust,its not the 316,well should not be.If you buy new 316 stock bar or sections it should be marked green at the end,an acid test to proove it can also be done.

Cleaning things like rigging screws and even the wire is a very simple job,no effort required,just Oxalic Acid powder and hot water,leave the parts to soak over night or a day or two and all the rust should be gone.How easy can this be!


This half kilo of oxalic acid will clean an entire boat,use it to take rust stains off your decks,even sails.do not use it on alloys or chrome plated items and always wash clean with fresh water after the process,its very easy to apply with a small trigger finger type hand gun.



These are very nice 12mm Norseman terminal ends,check the last pictures to see how they cleaned up after a nights soaking in oxalic acid fluid.



Left click the pictures and check the surfaces,some rust and dirt which is not so easy to get clean when its deep in the threads and sockets.



This is not bad for an over nights soaking!



Clean and ready to refit,use new olives when re fitting always.

There are four of these,they are for sale.

R McB

Thursday 11 August 2011

Rigging Matters

We can read that two ways but the fact is our masts are held in place with a whole range of stays and related fittings,when did you last look at yours with more than a passing glance?


A nice sized toggle to the lower end of a rigging screw.


The same toggle on a rigging screw that has a Noresman terminal,those studs and terminal ends are worth their weight in gold when we need to do changes on the boat when at sea.



A swaged stud end,it can also be supplied as a fork end,depending on the application.These ends can only be swaged by a rigger with a swage machine.You can of course remove your existing wire stays one or two at a time and take them to a rigger for replacement.Be sure to replace the stay removed with a secure halyard while the rigging stay is removed.



Cast bronze toggles made by Lewmar,very nice too,some rigging screw bodies have a bronze with chrome plating,they can look like stainless.They are better when a stainless stud or fork end screws into it,the two metals tend not to seize,while stainless on stainless does.



A closed body rigging screw,very strong and easy to clean,there is little choice between the two,excepting we can not see whats going on inside this type.



Open body screws,these are chrome on bronze and made by Noresman,very nice quality.

Cleaning stainless rigging is painless and easy to do,dismantle the parts,degrease with water soluable cleaner,then place the parts in a bath of Oxalic Acid fluid.Oxalic Acid can be bought from any decent painters store.It comes in a dry powder,mix a cup full to about three liters of hot water,then when the powder has disolved,place the parts (this can include the 316 stainless wire also) into the mix and leave untill its clean.

Note,if the parts have been chromed,the acid will remove the chrome,so be sure to check before you  start.A re chrome job is not expensive though and does make your rigging screws look new again.

Inspect all parts before you repalce the parts and screws using a lubricant such as Fluid Film or Tef-Gel,we can supply you with either.

R McB

Nereida visits HBYC Marina

One of the OCC (ocean cruising clubs) more well known members Jeanne Socrates arrived a few days back,she was on a less than protected marina berth and I asked Alan the marina manager if he could find her a better berth? To my surprise he found her one of the most protected spots we have!


Thats a nice sized boat to do what she does,namely sail single handed around the world on two boats more or less back to back.

Check out Jeannes web site @   http://www.svnereida.com/  your in for a good read.



Close to the marina walkway and Alans office,this is a handy place to be.

R McB
Port Officer for the OCC



Tuesday 9 August 2011

The Perkins marine diesel engine,we look inside one.

This is an unusual picture to see at the marina,its a six cylinder Perkins engine that had cylinder head bothers and was starting to smoke.I was told some object had found its way down the inlet tract,so they decided to do a full strip down here in Cape Town,then out came the block too!

What a nice design in engineering,each bearing is supported on both sides and check those small webs inside the crank case,all there to allow for a lighter casting that remains stiff,there is a lot of thought thats gone into this engine.

Click on the picture to see in a larger scale,note how nice and clean this engine is,which should indicate its been serviced well. I would expect the bearings to look fine when the end caps are removed. Note the red paint,what kind of paint is this that can stand a life in a diesel engine? I have seen it before,it will be there for a number of reasons,one the cast block is painted after its been made,this stops surface rust when the engine is later machined and washed clean prior to assembly but its also there to ensure the oil runs down the block surface to the sump faster,some race engines have this process applied for the same reason.

The inside of a Rolls Royce Merlin engine fitted the the Spitfire airplane for WW2 was hand polished inside,thats the block crank and con rods,all to enable more power and get the oil back to the sump.

Monday 8 August 2011

Hout Bay Marina today

This is winter,tell me more,its been such a mild winter that even now the SE trades are blowing.


What a nice place to keep a boat and also be lucky enough to live close by.

R McB

Marine engine heat exchanger water pump

In the case of a marine diesel with a heat exchanger we need two water pumps,one is the raw sea water pump,normally with a rubber impellor but another pump that is often fitted to the front of the engine as found on most automotive applications.


This is the water pump from a Perkins 4108 diesel,it may well fit other Perkins applications too.



The inside which runs in the coolant,I say coolant as you should always have an additive such as antifreeze to stop rusting in the engine block.



The impellor is supported inside and at each end by sealed ball bearings,they in turn are protected by carbon face seals,they are cooled by the liquid around them,so never run the system with out coolant and do not over tighten the fan belt as you will probably damage the bearings?



The front end of a Perkins 4108 diesel,which is a four cylinder engine giving around 46 bhp depending on use.The upper left pully powers the fresh water system,the upper right unit with the round plate and six screws is the Jabsco raw water pump,this is driven by an internal key way inside the engine.



Sample water pump seals,these are not off the Perkins 4108 engine but are ex stock off another application.

Carbon water pump seals,three new ones in the front,the rear ones are used but servicable.These may be outside the ability of some to fit,we need a press to remove the pump shaft as a start,I would recomend anyone going cruising to either carry a spare fresh water pump,or the correct seals and bearings as a kit,to enable a pro motor engineeers shop to rebuild your pump for you.

Note,failure of these pumps tends not to be instant,you will normally note a slow drip from the escape hole provided in the pump,when this is seen make plans to either change the pump then or as soon as you reach port.

R McB

Jabsco raw water pump impellors

Why the name Raw water? well in the case of a marine diesel engine the cooling is normally done by taking ,sea water directly from the sea and then either cooling the cast iorn block directly,or cooling the engines fresh water heat exchanger which runs a fresh water coolant through its pipes.The sea water is used in one pass over the heat exchanger pipes then dumped into the exhaust exit just where it enters the rubber exhaust pipe,then out through the exhaust and back into the sea.

Jabsco and also Johnston make similar pumps,many parts are interchanglable,just be sure you carry at least one spare in case the one in service fails.

Impellors for the Perkins 4108,the BMW/Hatz and the Yanmar GM10 diesels.

Note the contents of each box,some impellor kits contain only the rubber impellor,some have gaskets and even new face plate screws,its good to carefully inspect the kit before buying it?

The small impellor fits the Yanmar GM10,part number 21414-0001B,the  pump is mounted low down on the front of the engine,its not in the best of places as the main fan belt pully masks one of the three bolts holding the raw water pump in place.Its as easy to remove the entire pump body and work on it on the bench.

Note,if you do this,do not turn or crank the motor with the pump removed!

Raymond from Manex Marine, once suggested a similar sized Jabsco impellor,saying it was the same shape and R10 cheaper,it fitted too but soon stripped its center drive,as it turns out the Yanmar pump requires an impellor thats about 1mm thinner,so check that part number,the Jabsco part book mentions the correct Yanmar one.