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.
Fischer Panda Mini 12 in its permanent new home
Panda gensets come from the factory ready for a siphon break
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.
I’m using Shields 250-series 3/4″ exhaust/water hose for the siphon break
90° barb fittings bring the hoses as close to the enclosure as possible
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.
Hoses installed from the Panda to the Vetus siphon break
The siphon break installation is complete
Next up: the waterlift muffler.
I removed the genset exhaust hose and fitting that exits the sound enclosure
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.
Exhaust fitting in the as-received orientation
This wouldn’t work for my boat
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.
So I made some aluminum spacers and a backing plate
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.
One hole down, two to go
The fitting fits the hole and I straightened out the flange so the hose fitting and hose will be parallel to the enclosure
Barr Rust 235 High-Solids epoxy primer coats the aluminum spacer and backing plate
The backing plate will go inside the fiberglass enclosure; the spacers will be outside
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.
That’s just about perfect
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.
I’m using Shields 200-series 1-1/2″ hose for the exhaust
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.
Back at the workshop, I cut more scrap aluminum to make a base for the muffler
Muffler base parts are clamped in place and tacked on each end
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.
My aluminum TIG welding does not look like a stack o’ dimes…
…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…
Opposite side set up and ready to TIG
That’s a good enough pile o’ nickels, dimes, and quarters
The muffler base looks good
Back at the boat, I marked off where to drill and started making holes
Yup…that’s what I had in mind
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.
Back at the workshop, I drilled bolt holes for the muffler in the muffler base
With all of the welding, test fitting, and hole drilling done, I sanded the muffler base and coated it with Barr Rust 235.
1/4-20 stainless fasteners and neoprene rubber isolators will hold the muffler to the base
Tef-Gel is on the fasteners, and this assembly is ready for installation
Nice!
Exhaust hose drops 45° out of the sound enclosure, with minimum 1/4″ clearance all around
Waterlift muffler is directly under the Panda, as per the manual
Boom
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
1969chriscraftroamer46 