New Projects From Hans Muller

The trip to Annapolis to attend the 2002 PCI Annual Rendezvous was not without its hazards. Yes, we had a great time, but unfortunately we were able to see many of the projects that Hans & Renata Muller have done for their Gemini. I think I came away with at least a years worth of work! :-)

Rudder Adjustment- This one is pretty easy. He added white PVC pipe and grey PVC electrical conduit to the rudder controls, color coded for up & down. Really helpful to be able to move the rudder when there's a load on it while sailing.

Refrigerator- Definitely more work, but important for efficiency of the box of the Dometic refrigerator. He added more closed-cell foam insulation in 2 layers to the outside of the box by working it between the outer box surface and the fiberglass enclosure. The first layer is flat, but the second layer is tapered to fit the space available. Hans managed to get insulation on 4 sides: top, bottom, sides. The rear isn't accessible because of the evaporator coils.

The door is a little more difficult. Here he added insulation by attaching a 2" x 2" aluminum U-channel to the door. The inner and outer edges were trimmed to about 1" and the inner flange attached to the inside of the door. The original teak door front is reused and the space created by the wider channel is filled with more closed-cell foam panels. He had to do a little trimming here and there to clear the hinges.

Now the change I think is most important: the Dometic refrigerator has a chimney above the burner which is used to heat the pool of refrigerant (ammonia). The exhaust end of the chimney doesn't vent to the outside directly but rather into the space above the refer and around the window above the wheel. When the window is down as it usually is on Goosebumps, heat collects in this area raising the operating temp of the instruments and venting the hot air past the small gap in front of the window into the helmsman's face as they lean toward the screen of the navigation computer. Not only that, the heat also surrounds the refrigerator which interferes with the cooling. To solve this, Hans took the simple expedient of adding an extension to the chimney which he lead to the outside where it vents directly into the cockpit instead of behind the instrument panel. Definitely easier to do with the earlier 105s since the newer cockpit doesn't have vents on both sides of the wheel, but the concept of getting heat from behind the instrument area (the "dashboard") is what's important.

While we were on the Muller's boat, Hans checked with a thermometer to see if the temperature on the top shelf of the refrigerator was as cool as other areas of the box. Sadly that stagnant area is still significantly warmer than the rest of the interior (+30 deg F?). Hans felt that it would take some holes in the freezer door to solve the problem.

Holding tank- Hans replaced the 18-gal holding tank with a homemade fiberglass 30-gal tank that was carefully thought out to put a drain at the lowest aft point. He used PVC pipe for the drain and fill lines with only short pieces of flexible section for attaching. One very clever feature is a sprinkler head mounted inside the tank for washing it using their deck wash down system. Using a valve operated from inside the head compartment, he can turn the pressurized sea water on/off. Plus, unlike other early 105s, the tank can be drained directly out the thru-hull. I have to believe what Hans said: it took him longer to do this project than it takes Tony to build the whole boat! :-)

Forward Locker Vent- This has been a problem on Goosebumps since warm weather arrived. The deck heats up from the sun and that heats the hanging locker and the 2 smaller lockers. There's really no way to get rid of the heat. Hans mounted a Nicro Marine solar powered vent in the lid of the anchor locker, then cut vent holes into the aft bulkhead of the anchor locker. This bulkhead also serves as the back wall of the center storage locker in the forward stateroom. With the addition of a hole between the hanging locker and the center locker plus vents in or around the locker doors, the fan will now extract air from inside the boat thru the hanging locker and the center locker and out through the anchor locker. Ingenious! I think a variation of this will work nicely for the area under the nav station where we've gotten mildew on occasion.