Working on the engine AD290 Arona

In these rainy days I have planned to do some maintenance to the engine.
Being a 45 years old engine and not knowing his previous owner/history I have doubts on what to do.
Shall I just use it as it is (it starts first go and sounds good) or shall I do some maintenance now that it is on land and easy accessible but risking to break some parts that are out of production?
I went for the second one and it was a good choice.

I am only planning to open the oil pan to check inside the engine and to open the flywheel to check for any signs of leak and also to take a look at the gearbox.

Although the engine oil looked fine once opened it oil pan I have realized the the internal pre-filter was almost 90% covered by sludge. this meaning that I would have had some serious problems not to far away form now if I didn't check.
This pre-filter didn't come off easily (as surprisingly all other bolts of the oil pan did) so I have decided to use a little basin filled with diesel so to let it work overnight and hopefully dissolve the sludge stuck on the inside of the filter.
Also the pan it self needs some welding as from the inside you can clearly see that there is a crack probably due to an incautious landing of the engine,

After welding the crack on the oil pan I have scraped away the old paint, sprayed 2 layers of anti rust primer and then varnished.

The oil pan needed a new gasket. As I did this before on another engine I've used a layer of cork. This time I will try to use only cork because I am afraid some sikaflex would spill inside the engine when tightening the pan to the engine.

 


Next step was to checkout the flywheel.
Once opened the front cover I have had a really bad impression of the status of the flywheel (all rusted) probably due to lack of attention from who did this job before... there was no seal on the cover/lid so seawater and generally salt could easily penetrate inside and do its work.
Luckily it looked much worst than it really was. I have cleaned the wheel with some wd40, then some diesel and manual sanding. looks perfect.
I have also checked the starter engine gear.  general cleaning and some grease.

 

Rudder and propeller

In order to do a better job on the hull I had to remove both the entire rudder and the propeller.

The propeller oring will also be changed and the rudder needs some maintenance (apparently is a common thing on these conyplex models).

Inboard engine: 1972 Arona 20hp

Since its launch in 1972 Mizar had 2 engines mounted. the original from the conyplex shipyard was a Volvo MD2B 18hp which history I don't know.

In the late 90's a Lombardini FOCS 25hp was mounted. Although a good engine with a combination of power and lightweight, some parts of it are in aluminium which means a really strict schedule on zincs... which wasn't the case being Mizar abandoned at the buoy for 5 years.. long story short, there isn't an engine on the boat anymore.

So I have been looking on the internet and also thinking what kind of enige I should put on Mizar.

New engines are super expensive and therefore not on the possibility list for the moment.

Old engines are usually very reliable and easy to maintain but that's if previous owners have been taking care of it...

Finally after long weeks spent searching the internet I have found not too far from my home an Italian brand engine called Arona.

The company has shut down in 1983 but apparently these engine are quite good and basic which is what I need.

The model is a AD290 Arona 20hp from 1972. I bought it the same day the advert was posted on the internet. The second hand outboard demand is incredibly high and these engines are sold fast. 

The engine needs some maintenance but kicks on at first attempt and also the alternator works well.

Another plus for these old engines is that the maintenance manuals are still accessible and very well written explaining and picturing all main activities you need to do on it.

more info on these engines can be find on the links of this blog.

-General Info and links: http://people.plan.aau.dk/~poul/Arona/

-Maintenance manual PDF: http://motoren.ath.cx/pdfs/arona/Arona%20AD_290M_maint.pdf

-Workshop manual PDF: http://motoren.ath.cx/pdfs/arona/Arona%20AD_290M_workshop.pdf

Minus points are its weight, almost 200kg, and the fact that spare parts are not so easily accessible but some of them can still be found from main producers (bosch, etc) look here:

http://people.plan.aau.dk/~poul/Arona/additional.htm

Sea cocks - Through hulls

As usual a big concern was how good are the current through hulls?

On the contest 29 these were melted into resin I guess as it gives strength and durability and they were meant to last long. still how long is long? I suspect that they have never been changed since Mizar was built back in 1972, so that's 45 years today.

they do look pretty solid I could only change the valves...but I do think that once out at sea I would spend my sailing days asking to myself should I have changed them??

As usual I went on the internet and got some info about the material (bronze) the types of through hulls and so on...

Apparently when you see pink colour that's a sign of corrosion. and some of mizar's sea-cock did look pinkish in some parts.

So I have used a hammer and screw driver to take away the resin. not too difficult. 

What was difficult was unscrewing the sea-cocks. I have tried with wd40 and banging here and there. but still not working ...although it made me think how strong these things are? do they really need replacement? (the answer later on will be yes).

So eventually I have decided to use the angle grinder and cut the seacocks paying attention not to cut the hull.

Out of 8 seacocks 6 where incredibly strong... but the last 2 (the 2 large drains from the cockpit) literally broke down in my hands. Now I am super glad that I went through all this work.

Later on I have decided to remove also the LOG thru-hull  which being made of composite plastic usually are fine for many years to come but I did not like the sate of the sealant which was "jellish" and sticky...  this turned out to be a challenging job as the sealant was preventing the plastic bolt from unscrewing and I was almost going to break it until I started warming it up with hot air and slowly taking the sealant apart with a small cutter... after 2 hours it finally unscrew without major damage.

Sanding the hull

It took almost a month to understand what to do and how with the hull.
Gathering information both from internet and fiberglass technician was not so easy and it came not all at once but in bits and pieces.

At first I have asked the marina people a price offer for the sanding (they have the machine which actually throws sand and that should be easy and quick) and it was acceptable, around 650euros. Luckily after I have agreed, the "sanding man" ( a friend of mine) told me that their sander is a less powerful one that only smooths the surface and will only get to the gelcoat. so this option went down.

So I went through sanding myself with a orbital sander (a basic bosch model borrowed from a friend) but after a week sanding (8/10 ho

urs in total... I'm doing this project during my spare time) the result was that I have only taken away the antifouling and the gelcoat that was still there was not in good condition and needed to be taken away also to show what the real situation was under there. not a job you can do with a orbital sander like the one I had.

Now after a month I went all the way down to fiberglass and the boat is now free to dry and shows other little repairs that need to be done before re-coating with epoxy.

It took me so long also because it wasn't so clear which instruments where best to use. After spending days looking at professional orbital sanding (well expensive) and changing my mind 100 times the fiberglass technician showed me how he does it!
With a common angle sander (but that has the option to set the speed/power) and a flexible pad with sanding paper grain 36. it was incredibly quicker and easier that using the orbital sander. you just need to pay more attention not to make a hole as this machine is much more powerful. with this method it took me 14/16hrs in total.

As part of the equipment I have also used 2 disposable dirt suits, a 3M dust mask (the one with replaceable filters) and full glasses/mask that I must say it was the most annoying thing as it kept getting foggy every minute.

Now that the hull is all exposed it has to be washed with a pressure washer to open up pores and take the acid away.

Getting the mast down

6 october 2017,

Getting the mast down was an experience

.... luckily I had some help. after putting the ropes on place to hold the mast sideways and from the bow (using the spinnaker pole to have an acceptable angle) to the winch.  it went smooth and perfect for 3 quarters of its way down. unfortunately the rope wasn't long enough and we've stopped to attach another rope....here it came a wind gust which pushed the mast sideway making the whole system collapse. ouch! luckily nobody got hurt and the mast safely landed on the hill next to the boat.

the steel mast holder/foot got bended and the genoa furler got bended too...it looks worst than it is i will get it mended easily form a local iron worker.

Osmosis

 While dive-cleaning mizar at the buoy I have noticed at least 3 blister as big as a 2 euro coin. when mizar came out of the water I have realised it wasn't a matter of 3/4 blisters but hundreds. Apparently, at some point of her life, previous owners have already treated her and you can clearly see the grey fillings of old blisters.

I have never came across it in my life but everybody is scared about osmosis especially those who don't know much about it. ...the more I acknowledge the matter the less I fear it.
Due to fiberglass thickness with a good dryout and a good epoxy treatment it should be ok.... in the future the boat will need attention and some time out of the water at least every 2 years.