Tuesday, March 21, 2017

Too much paint over the years

Every year, when Tortuguita is hauled out of the water, the bottom gets painted with antifouling paint.  This paint keeps the sea creatures from sticking to it by a combination of biocides and ablation.  Ablation is a continual sloughing off process over time.  Ideally, after a year of cruising, all the paint should be worn off.  That way there would be no yearly build-up.  It never works that way since if all the paint ablated, there would be barnacles stuck to the boat where there is no paint.

Ablative paints are can be hard or soft.  Soft will ablate easier and is good if the boat is sitting for long periods in a marina but will wear off faster when moving.  Hard is better if the boat is moving but doesn't sand off very easily. 

Pressure washing and light sanding are usually all that is required prior to a new coat of paint.  Usually 2 coats are applied with more at the high turbulence areas such as keel and waterline.  I figured out that we have 12 layers of paint with 24 layers at the waterline.  The total weight of this paint is around 300 lbs.

I've never seen this anywhere, but from the appearance of the cracks in our paint, I have determined  that if you apply hard ablative over soft ablative paint, it is like building a concrete road on mud.  The hard paint will move around and crack.
As long as the hulls are in the water, everything was fine.  But, with the boat sitting on land in the heat of the tropics, the paints will expand and contract and the hard layers that sit atop the soft layers cracked.

The only way to fix this is to completely remove all the paint.

In Australia we got a quote of $3000 for removing the antifouling by abrasive blasting.  This process is not very accurate and also removes the fiberglass layers.  

I figured that since we were going to a part of the world with cheap labor, that I will save money by waiting so I just sanded the cracked paint at the waterline and off we went to S.E.Asia.

Saturday, March 18, 2017

Is the fridge supposed to be warm?

Those words strike fear in the hearts of just about every cruiser.  Our air cooled Frigoboat AH35F refrigeration was installed by the previous owner and has worked flawlessly since we bought the boat.

The most likely culprit of a failed fridge is the evaporator plate.  It is made out of thin painted aluminum and a small bit of corrosion can cause a leak.  This is a $100 fix.

The next most likely cause is the compressor.  Either the actual compressor or the electronic controller could cause this malfunction.  These cost $300 and $200 respectively.  The good thing about these units is that one company, Danfoss, makes them and spares are available everywhere.
The compressor seemed to be running but not very hard.  The current draw, which is usually around 6 amps, measured only 2 amps.  When attempting to release some gas from the access valve to see if there was pressure in the system, nothing came out.    Could be the valve, or more likely, there's a leak somewhere.

We carry freon charging hoses and guages.  Usually you can buy 12 oz cans of R134a freon at the auto parts stores.  It's the same as used in automobile air conditioning.  Not here in Malaysia apparently.  All you can buy here are 30 lb. tanks.  I found a guy that had one with about 1/4 remaining so I bought it from him.

New High Temp HNBR O-ring Installed
I pressurized the system with a little freon and immediately found the leak.  Turns out that it was a failed o-ring at the quick disconnect fitting.

With that fixed, I did 5 fill/vent cycles to get most of the air out of the system and then did a full system charge.
Purging and Charging the System

Two good references to use for servicing these little systems are:


Evacuation Procedure without a vacuum pump
1.  With the new compressor installed, turn on the compressor and depress the access valve on the high side of the system.  Monitor the pressure on the low side of the system.  When the pressure is as low as it will go, close the access valve on the high side of the system and turn off the compressor.  This process will take about 5 minutes.
2.  Charge the low side of the system to approximately 14 psi.
3.  Wait about 3 minutes for the pressures on the high and low side to equalize.
4.  Turn the compressor on and depress the access valve on the high side.  When the pressure on the low side is as low as it will go, let the high side access valve close and turn off the compressor.
5.   Repeat steps 2, 3 and 4.  Note, on successive evacuations, the low side pressure will not go as low because of the absorption of refrigerant in the compressor oil and it’s slow release.
6.   Charge the low side of the system to approximately 14 psi.
7.   Wait 3 minutes for the pressure to equalize.  Turn on the compressor and depress the access valve on the high side.  This time, when gas is no longer coming out the high side access valve, let the valve close.  The air is now purged from the system.
8.   Charge the system with the appropriate amount of refrigerant and turn on the compressor.
9.  Make appropriate adjustments in system charge if necessary.

Thursday, March 16, 2017

Anchor Chain Re-Galvanizing

Our first anchor chains were 200 and 100 ft lengths.  One for each anchor.  The standard length comes in a 200 ft drum.  That chain cost $800 lasted 3 years.  It was replaced in 2009 and ended up completely corroded in 4 months.  Fortunately it was under warranty due to a bad galvanizing process.  Our current 300 ft chain was bought in 2009 in Ft. Lauderdale from Secure Chain and Anchor for $1000.  They were really great and were able to cut the 300 ft piece from a longer 1000 footer.  The price of $3.30/ft was also much better than the chandlery price of $4.50/ft.

We have an anchor on each end of the chain and find it very versatile for using as either one very long run for deep water or splitting the difference while using two anchors for more security in more shallow water.

The chain was getting pretty rusted at the most used end but did seem to have some life left in less used end compared to other boats here in the boatyard.  It would have made it a few more years but would have taken a toll over that time with thinning and corroded steel links.

As luck would have it, the marina office was arranging a galvanizing run to Butterworth, Penang.  There were 3 of us sending our chain and 2 were sending their anchors.  My share of the transport was $.30/ft.  The chain cost $1.50/kilo ($1.00/ft) for double dip.  Sounds like an ice cream cone.

All dressed up and nowhere to go

So for $1.30/ft we are now able to keep our hard to find 300 ft length.  Keep it in better condition from corrosion, and hopefully it will last another 7 years.