Aging marine engines.

Our boat is already 20 years old. It has Volvo MD2030 engines, and in the last years I have been reading more and more posts about older Volvo engines and problems that seem to originate from corrosion. Coolant disappearing, rusty coolant, leaks. 

The MD2030 and many other marine engines has a freshwater and a saltwater cooling system. They are supposed to be separated. But with wear and corrosion there are possibilities that the saltwater can enter the freshwater system. The freshwater coolant can also find disastrous ways as a result of corrosion. The latter happened to us this summer.

We found ourselves in a small island harbour with hydraulic lock in the port engine. Could not be turned. Water in the cylinders was the first thought, and it was correct. All 3 were full of coolant. But where did it come from? The heat exchanger housing had been off a couple of years ago, looked OK, so a cracked engine top was suspected. After dismounting it nothing wrong was found. Luckily, via some social network groups I was steered to inspect the heat exchanger housing thoroughly. A tiny hole was found in the exhaust area. Probing it, the edges fell apart, and the hole was suddenly big. Corrosion had eaten the area. 

We had to buy a new heat exchanger housing. They are quite expensive. Trying to find a welder could have been an alternative, but success was uncertain, and so was the time spent in the process. 

After returning home at the end of our sailing season, I cleaned up the exhaust area. The hole got even bigger. 

But still I had a hope of making a repair. The starboard engine has gotten rust in the coolant during summer, and I fear something the same can happen to it. I believe I need to replace that heat exchanger housing too. So I brought the old port one to a nearby welder. He was a bit sceptical because he thought the housing is cast aluminum and difficult to weld. Anyhow he managed to weld it. It was like welding in bisquit material he said, and there is of course no knowing how long it will last. The area was painted with epoxy primer, I do not know if it will have any anti-corrosion effect. 

The plan is to mount the welded heat exchanger housing on the starboard engine. Then I can see if the new coolant will not become rusty. And check on the other housing, maybe have it welded if there is a small hole in it. I paid the equivalent of £1000 for the new part, so a good repair of an old one is tempting.

Stowage compartment dividers.

Two prototype stowage compartment dividers were made many years ago. They came out of the need to stow spinnakers in an easy to reach and easy to stow area. At the same time a possibility for more rapid deployment was desirable. The Privilege 37 has two quite large stowage compartments in the bows. Larger Privilege yachts will have even more space. It is not advisable to store more heavy items than necessary in the bow of boats, but fairly light spinnaker sails should be OK.

I had to change some of the grommets this spring, and since this principle has worked fine for us, I thought I would share it. At the same time I believe a lot of people are already using the same idea.

The fabric used is nylon sailcloth. It is strong and has a smooth and slippery surface, so the sails go in and out without much friction. Some kind of attachment points for the grommets along the edges are needed. And some hooks so the top parts can be taken loose and kind of "open the bag" on top for deployment or stowage.

This way the spinnakers are stowed along the sides of the compartments, leaving space available for entry into the rooms and stowage of other items. The sails are stowed in a dry space, and no sailbags are needed. When stowing, the top of the spinnakers are fastened to the rim of the hatch. Then the spinnaker in the sock is slid into its compartment. The dividers contain two compartments, separated by a string of sailcloth. The one closest to the hatch will of course be easiest to use, but the system works well for both. 

The picture shows the compartments in the "closed" position. The hooks can be opened to open up the top. The hooks are then attached to another point to widen the opening. I prefer to take the whole sail in the sock on deck for deployment, but I have also hoisted it directly out with the halyard in light winds. It can also be seen that there are two compartments. 

The divider taken out for some repair. I used aluminum grommets at the edges. They are too soft, but have held up so far. The grommets at the opening are often pulled hard to press the sail into position, so I used brass ones. At least I thought so, they bagan to rust after some years. So now they are changed to larger ones and real brass.

If the spinnaker is wet when taken down, I do not put it into the stowage room. It is put directly into a small sailbag that is tied to one of the nets. Then it is dried when that possibility comes.

Speaker covers

No big projects this between-season period of winter 19-20. Only a lot of smaller repair and improvement activities. Which is perfectly OK :).

A project slightly off the beaten track is new speaker covers. I think we were on our third set of outdoor speakers now. There has been nothing wrong with the speaker elements themselves. But the outside covers have crazed and cracked and become ugly.

Plastic expands and retracts considerably with temperature. So after the covers have been snugly screwed to the hull, they will start to work back and forth, finally cracking up the area of the screw holes. In addition, the plastic seems to become more brittle with time, so if the covers are removed for some reson and re-fastened, it is easy to overtighten the screws slightly, cracking the plastic. I have tried to use rubber backing gaskets to prevent cracking, but in vain.

Basically, I like this shape. There are other shapes, as thicker discs with a more solid area for the holes. But they have, in my view, some disadvantages. More bulky speaker covers protrude too much, and on a sailboat the ropes will easily get caught by them and possibly pull them off. You could also more easily hit them with body parts when moving around during sailing. So I believe the speaker covers should have a slim and low shape.

I could find no sets of speakers to fit my requirements. Consquently I started to think of making some myself. They would have to be solid, low profile, cheap, easily repaired and have an acceptable appearance. Easier said than done, and it took some time to find a concept.


Some small 2mm glass fiber sheets were found on eBay. They were cut to discs, then to rings, then doubled to leave space for some kind of mesh to be fastened inside.

The outside perimeter was easily sanded to a smooth finish by fastening the disc (before cutting out the inside and making a ring) to a table drilling machine. The inside was a bit more tricky to smoothen out. It was solved by making a simple jig that could be used in the same drilling machine.

With that the hardest part was finished. The rest was to spray paint, glue in some Phifertex as a mesh, and put a layer of thin fabric behind as a water spray barrier.

This is obviously before the spring washing and cleaning this year, but it shows the final product installed. I hope it will last for a while. At least it is repairable.


I chose to keep the speakers and the covers separate. To be able to mount the speakers from the inside, I had to find suitable speakers that were supported by a square mounting plate. Otherwise I could not get them through the hole and still have "ears" to get some fastening bolts through. (The inside area requires a lot of dismantling to get full access).