Friday, July 15, 2011

Rudder Rebuild

weeping water from rudder
Our Rudder was removed from the sv Solace after investigating some weeping from the rudder. We also drilled into the rudder and discoverd the rudder had a cavity and poured out water.
Upon removal we also saw the rudder stock had corroded where the packing gland material sat, and with the ingress of water into the rudder, also wondered about the quality of the stainless form inside. It was decided to rebuild the rudder from the ground up.

Corrosion on the rudder stock at Picture on right.
We also changed to a seal rather than packing and readers can read that under our blogs in the rudder section. All dimensions of the "old rudder" where carefully recorded, so as to ensure as near as possible, a duplication. Photo's where also taken where necessary.

Cutting into the rudder reveled nothing more than "shop sweepings" with a little resin. A large cavity for water to sit in and probably weeped it's way in at the top of the rudder, where the rudder stock joins the GRP. The rudder stock was cut away from the GRP and sent into an engineering shop to have the shaft repaired where the corrosion was. After completing that, they made a new SS form/frame for the rudder and attached that to the rudder stock

The rebuilt rudder stock with new frame attached and ready for phase 2.

A closed cell foam was fashioned in two halves to the dimensions of the old rudder, and machined with router so the new rudder stock would sit snugly inside the foam "shape".

To the right, the photo shows how the frame sits inside the foam prior to gluing the two halves together.

The photo to the left show the two halves under weights while the gluing process drys. Note, the two halves make one rectangular shape. and the outer shape is yet to take place.

The rudder is then planed to shape, allowing for the thickness of the new fibreglass covering.

Once the final shapeing is complete, two groves are machined into each side.
Hardwood strips where placed into these groves and they sat against the stainless frame and level with the foam surface. This is to prevent movement of the stainless frame inside the softer foam.

 Finally, the process of glassing over the foam begins. When completed a descent bead of sealant was applied where the rudder stock "disappears" into the glassed rudder blade. This job is not for those without some experience. It is slow and tedious work to get things right. About 6 weeks for completion. We probably now have a lighter rudder, and feel safer sailing across oceans knowing our rudder is right.
Finished and installed

Tuesday, July 12, 2011

Generator Shut Off Mod.

See below for original shut off mod.
We have in fact removed this mod. The main cause of the generator not shuting down was it has a protection circuit to protect itself should it slightly be overheated. Once you push the shut down button, it would continue to run with no load to help itself cool down before shuting down. In addition to our heat exchanger being clogged, we found some gasket material behind the sacrificial anode which bolts to the side of the generator casing seen bottom left on the photo to the above. This clogged the hose delivering water to the heat exchanger. The generator also has a high temperature shut down protection and it was after replacing the heat exchanger we had a high temperature shut down and that's when I found the additional blockage. The gasket material comes from the gasket on the end plate of the generator housing. I have a new gasket ready to replace for next season. The generator has raw water come via the RW pump and goes through the generator casing before going to the heat exchanger to pick up heat from the fresh water cooling from the engine. New Fischer Panda's have the cooling of both the generator housing, and the engine, cooled by fresh water and the sea water just passes through the heat exchanger. Due to potential corrosion I will be changing my FP next year to reflect the way FP now does it's cooling. Keep a watch out for that blog around April 2013.

Generator Shut Off Mod 2011
We have a Fischer Panda Generator  that has for some time had a shut down problem. i.e. It won't shut down from the control panel. A careful  inspection of the shutoff solenoid found no issues and the problem only presented when the unit had been running for some hours. In frustration, I used the valve at the fuel manifold to eventually have the generator shut down by starving it of fuel. However, because of the location of the valve, this would often take 5 minutes or there about. A new shut off solenoid was over $200USD and was no guarantee that it would fix the problem (it could be an electronic control module issue). Here's what I did.
I procured a fuel/gas solenoid valve off ebay for about $30USD and inserted it between the secondary fuel filter and the units own shut off solenoid. That is marked in the above photo with some red wire rapped around it.

The picture to the right shows a close up picture of that shut off solenoid.

There was not much room to mount the new shut off solenoid. The whole unit is encased in a sound proof  casing. I had to find a convenient location to mount the new unit. I used an area just under the existing solenoid, with the intention that if it didn't work, I could reverse everything back to the way it was. The unit was secured with cable ties and with a strip of rubber to prevent metal to metal contact and abrasion. I had a spare switch for this solenoid on a switch panel and wired that in to activate/de-activate the unit.
The picture to the left shows the finished installation, and while it could be a little more aesthetically pleasing, it is fully functional. ( After all, I'm in the Pacific Islands, where nothing is available to complete some projects). the generator now shuts down in less than 5 seconds when the solenoid is turned off. I suspect the OEM part is faulty  but who wants to pay over $200USD to fix that.
Cost; $30USD for the unit. Fuel hose and hose clips and wiring, I carried as spares. About 3 hours work.