With the Fischer Panda Mini 12 genset installed in its permanent home on new vibration-isolated mounts, I next installed the Vetus siphon break for the generator’s raw water supply and the waterlift muffler.
The in/out hose loop in the pic above ties together the two factory fittings in the raw water system that you (optionally) use for a siphon break. As I described in the Fischer Panda Marine 12 Mini DP Genset article, I’m doing every single optional thing that Panda recommends to ensure nothing unfortunate happens to this expensive piece of hardware.
In the pic above, you can see the new aluminum salon floor support I made to replace the OEM mahogany stick. I’ll permanently install it, including cleaning up the aluminum oxide and applying Barr Rust 235 high solid epoxy on the engine stringer later. It’s not a priority for splashing the boat in October 2022.
Next up: the waterlift muffler.
When I took possession of this 200-hour used Panda, the hose fitting that exited the sound enclosure was horizontal. Meaning, it wasn’t installed the way Fischer Panda recommends, which is that the exhaust hose should only slope down on its way to the water lift muffler…no flat spots…no uphill sections.
The FP manual is explicit about the exhaust dropping into a waterlift muffler that must be immediately under the genset. Not only was this fitting horizontal, it’s also pointing in toward the sound enclosure because the stainless steel flange is bent. If I just put a wrench on the elbow and pointed the fitting down at a 45° angle, the hose would run into the new white-painted mount I just made.
By the way, metal cutting jigsaw blades are useless on 3/16″ aluminum. The teeth almost immediately fill with hot aluminum. I find that 14TPI jigsaw blades are best for cutting small holes in this aluminum plate.
The previous installer used the super long 8-32 stainless machine screws to attach the fitting flange to the fiberglass enclosure with only tiny washers to spread the load on the fiberglass. Needless to say, that caused some minor cracks in the fiberglass enclosure. My approach with an aluminum backing plate will spread the clamping load from the four screws over a much larger area. The fitting will be held firmly in place without tweaking the enclosure.
I coated the bronze elbow with some grey zinc chromate I had laying around. But I didn’t mix up enough of the Barr Rust 235 to top coat it and make it pretty. Since my priority is getting the boat in the water next month, this is good enough.
It’s a bit unintuitive (to me anyway) but the 200-series no-wire hose is more rigid than the 250-series hose that has wire-reinforced walls. The 200-series wall is thicker, and in my experience this stuff remains supple and resists cracking for a very long time. The fact that it’s more rigid will be advantageous in the long run from the muffler on the starboard side to the OEM exhaust outlet on the port side.
I use 3/8″x6″x4″ aluminum angle left over from the Cummins engine beds, which works great for clamping parts in preparation for welding at 90° angles. The angle is thick and makes a great heat sink. And unlike the relatively thin 3/16″ plate I’m welding, the 3/8″ thick angle doesn’t warp even when it’s clamped to hot things.
…more like a pile of nickels, dimes, and a quarter or two. I don’t weld enough to develop the muscle memory required to consistently lay down a stack ‘o dimes. By the end of each TIG session, my welds are looking better and better. But then I don’t use that skill for a long while and it goes away.
That said, for the intended use here, these welds are fine. There’s good penetration and the puddle stayed nice and wet all across. If only I could be more robot-like with my torch travel speed and filler rod dab rate…
I was careful to install the muffler base a few inches back from the forward bulkhead (the white wall on the opposite side of the muffler in the pic above). That way, there’s good access to the limber holes at the base of each stringer where they’re welded to the bulkhead. Stuff can clog limber holes over time, which prevents water from flowing into the bottom of the bilge where it can be pumped overboard. Leaving some space will make future limber hole cleaning simple.
With all of the welding, test fitting, and hole drilling done, I sanded the muffler base and coated it with Barr Rust 235.
Exhaust goes up from the waterlift muffler to the Vetus gas/water separator, and from there the water will drop out and go off the boat with one hose while the exhaust gases cross over via hose to the OEM exhaust outlet.
This is great progress toward splashing the boat in October 2022. I’m waiting for some parts to come in so I can finish the Panda, so I’ll shift gears to another priority.
Next up in our 1969 Chris Craft Roamer 46 Refit: Making the Chris Craft Cable Drive Tachometers Work with Cummins 6-CTAs