1969 Chris Craft Roamer 46 Refit: Major System Test — Air Conditioners

One of the problems I had when I launched the boat in June of 2023 was a very slight leak from the original Chris Craft genset strainer/seacock I attempted to reuse. I decided to upgrade to a modern seacock, Forespar marelon (reinforced plastic), and Vetus strainer. When we transited from Deale, MD to our current home port, I kept the Forespar seacock closed but had a hose connected directly from the valve hose barb to the pump inlet just in case the valve, which is well below the waterline, was accidentally opened. Once at our home port, installing the Vetus strainer was the last step in commissioning the air conditioners.

The OEM Chris Craft strainer hose barb was just above the valve

I didn’t realize it at the time, but the  top of the Chris Craft strainer was well below the waterline. So, if I had to remove the top to clean the screen, even if I closed the valve, water in the hose, pump, manifold, and supply hoses would overflow the strainer when I removed the top. I’ll try a different approach with the new Vetus strainer.

Reconfiguring the pump inlet orientation for the Vetus strainer

I marked off the waterline on the 1″ round tube salon floor support

I welded a mounting plate to the floor support tube at the waterline

The waterline will be halfway up the Vetus strainer

With the system shut off, raw water will naturally settle to the waterline. I’ll be able to remove the cap and clean the strainer without water overflowing into the bilge.

That 90° bend in the short inlet hose puts more strain on the seacock than I like

So I replaced the straight Marelon hose barb at the valve with a 90° one.

I’ve had very good results using caulk to seal Marelon seacock threads

Seacocks use straight pipe threads, not self-sealing tapered ones

So thread sealant is absolutely necessary

Nice!

Zero stress connections

I was all giddy when I opened the seacock. Raw water came up to the waterline on the strainer, then filled the hose to the pump, just as I’d hoped. This was in mid-July, 2023, and it was 90° in the salon. The thermostats were set to 78°F. One by one, I slid the thermostat switches from OFF to COOL.

The raw water pump came on! Cold air started blowing from each of the AC units! Within 20 minutes, the V-berth AC unit shut off, having reached the set temp! The aft stateroom shut off after 20 minutes, and the salon hit 78° after 30 minutes! The AC unit and raw water pump shut off!

Success!!!

I should also mention that having the raw water exit below the waterline via the OEM toilet outlet standpipes makes it very quiet.

So that’s a major system that’s pretty much done. Booyah.

Next up in our 1969 Chris Craft Roamer 46 Refit: Aft Deck Window Moldings

1969 Chris Craft Roamer 46 Refit: Installing the Panda Genset Waterlift Muffler and Siphon Break

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

1969 Chris Craft Roamer 46 Refit: New Mounts for the Panda Genset

Before digging into the genset article, if anybody in the Mid-Atlantic region is thinking about installing Whisper Wall headliner like I did, I’m cleaning out the tent and have 23 sticks of 9-foot Whisper Wall track for sale for $1.50/ft. I just added them to my For Sale page. These are the tracks that connect Whisper Wall fabric panel-to-panel, not the tracks that go around the perimeter of the room. Send me an email if you’re interested (use the Tip Jar box to the right) .

Having gotten Egyptian and moved the Fischer Panda genset from the port to starboard engine stringers, next I made new vibration-isolated mounts that will place the genset even further outboard to starboard. There are several reasons for moving the genset further outboard: my gut tells me it’ll help with weight distribution, it’ll make space for exhaust hose that I’ll put under the genset to go from the waterlift muffler up to the Vetus water/gas separator, and it’ll make space for the vented loop hoses I’ll install, otherwise those would stick out past the inboard engine stringers.

180° panoramic shot of the scene for today’s article

You can see the coolant header for the port engine on the far left of the panoramic shot and the same for the starboard engine on the far right. The Panda genset was on the port side, so I got Egyptian and rolled it over to the starboard engine stringers.

You can also see that the engine room steps are centerline over the keel. That’ll pose a challenge when it comes to routing the exhaust hose for the genset.

The Panda in the original Kohler genset position

In the pic above, on the left, you can see the genset exhaust thru-hull that’s welded in. I’ll still use that as the exhaust outlet even with the Panda on the starboard side.

After getting Egyptian, the Panda in its new home

That grey, vertical stick in front of the Panda is an OEM salon floor support is primer-coated mahogany. It’s in the way of the genset installation. After I remove it I’ll make a new one out of aluminum, as I have elsewhere in the ER.

Making new genset mounts from old gas tank mounts

When we were in the demolition phase way back in 2008, I saved the 1/4″x2″x1-1/2″ aluminum angle that Chris Craft used for starboard and port gas tank mounts in the aft stateroom. I used two of them for the cradle for the new centerline fuel tanks and will use this one to make new mounts for the Panda genset.

By the way, the Harbor Freight metal-cutting bandsaw is a great tool.

Steel screws securing plywood to aluminum for 50 years makes removal a challenge

Chris Craft didn’t use Tef-Gel, so most of the hardened steel screws snap off

ONE screw out of nine came out without snapping

New vibration isolators

The Fischer Panda genset is mounted to the sound enclosure with very soft vibration isolators. But, this being a metal boat, I wanted to add a second set of vibration isolators between the new mounts and the engine stringers just in case stray harmonics try to get through.

Mark the ends to get rid of sharp edges

Drill holes for vibration isolators and stringer thru-bolts

Sand the rounded ends smooth

The smoothed edges have two benefits: it eliminates sharp things in the engine room and paint sticks to rounded surfaces better than sharp corners.

Drilled, sanded, and ready for the first test fit

Perfect!

PVC spacers will separate the steel bases of the vibration isolators from the aluminum engine stringers

Of course, the stringers are coated with epoxy, but PVC spacers will help ensure the steel doesn’t gouge into the epoxy.

The vibration isolators and PVC spacers also raise the genset two inches, which is a good thing. It may not sound like much, but without those parts the middle of the raw water pump on this Panda was 10 inches above the engine stringers. The OEM waterline was also 10 inches above the stringers, which means there was a potential sinking hazard if a hose fails and a siphon starts pulling water past the pump and into the bilge. By raising the center of the pump two inches (and I’ll be adding a siphon break per Panda’s installation manual), it completely eliminates that siphon potential. When the genset shuts down, the raw water level in the intake hose will drop to the waterline, which will be an inch below the raw water pump body.

ShopSmith bandsaw makes quick work of cutting the PVC spacers

ShopSmith 12″ disc sander smooths and shapes the PVC spacers

Genset mounts are coated with Barr Rust 235 high-solids epoxy

Time to get Egyptian again

I had to jack up the genset, pull the aluminum angle genset mounts I made earlier (that were too short), attach the new mounts, then roll the assembly outboard until the vibration isolators are in position over the stringers.

Tools of the trade for gettin’ Egyptian

It’s pretty amazing what you can do with mahogany blocks and levers, and 1-1/2″ PVC pipe scraps. A Harbor Freight porta-power comes in handy, too. Like the metal-cutting bandsaw, the porta-power is a Harbor Freight tool you won’t regret buying.

Salon floor support is out of the way, but one screw was stubborn

Chris Craft left bare aluminum in direct contact with the wooden support base

Wood absorbs water, even humidity from the air. Wood in direct contact with bare aluminum turns the latter into Al3O2 white powder…basically rust. This screw was extremely difficult to remove because of it, but at least it didn’t snap off.

I’ll sand and epoxy coat this area later. It’s not a priority for splashing the boat this year

Gettin’ ready to get Egyptian

The new mount is attached on the aft side. Next I jacked up the forward side and attached the other mount.

After rolling the genset outboard, I used levers to lift the inboard end and pull the PVC pipe out one-by-one

The Panda more permanently in its new home

I drilled one 1/4″ hole for the outboard vibration isolator, then pivoted on the bolt with levers to get the genset in its final position

I drilled the 1/4″ holes in the stringers for the inboard vibration isolators and bolted them in place. But the genset hangs over the outboard isolators, so could only drill one hole for each of the outboard isolators. I had to disconnect the genset and mounts from the isolators, jack up the assembly, and move the genset inboard temporarily to drill and install the last two bolts.

Gettin’ Egyptian one last time to drill and install the outboard vibration isolator bolts

Final step: Tef-Gel in the holes in the aluminum stringers before torquing the stainless bolts

I also positioned the Vetus gas/water separator to verify proper clearance

I’ll put a waterlift muffler under the genset. Exhaust gases and raw water will go up a hose from the muffler to the left hose barb on the gas/water separator. Water will drop out the center hose barb, and cooled, dry exhaust gases will exit the right hose barb before heading over to the exhaust thru-hull welded to the hull on the port side.

New Fischer Panda mounts and vibration isolators are done

Next up in our 1969 Chris Craft Roamer 46 Refit: Installing the Panda Genset Waterlift Muffler and Siphon Break

1969 Chris Craft Roamer 46 Refit: Fischer Panda Marine 12 Mini DP Genset

I think I’m still on track for getting the boat out of the tent and splashed this year. Somebody ought to set up a betting pool…

I bought a 200-hour Fischer Panda 12kw genset back in 2009, shortly after the paperwork SNAFU got resolved. I had it craned into the boat along with the Cummins engines, the refrigerator, and washer and dryer. Fischer Panda is a German genset with a Kubota 3 cylinder engine, and it’s quite small for the amount of power it produces.

Getting the genset installed is a priority for splashing the boat because I’ll need a surveyor to give his stamp of approval to put the boat back in the water. Since there’s a raw water thru-hull and seacock (valve) for the genset, I suspect the surveyor and insurance company will, in the very least, want to see hoses fully connected from the inlets to proper outlets.

I’ll be installing the marine air conditioners for the same reason: any system that uses raw water should be in such a condition when the boat is splashed that it doesn’t pose an unnecessary sinking hazard. If there were no hoses hooked up and the seacock was the only thing keeping water on the outside, it’s a single point of failure. Having the hoses and equipment hooked up eliminates that potential problem.

I positioned the Panda on the port side since that’s where the original gasoline powered Kohler 10kw unit was installed, and the exhaust thru-hull is on that side. But for a few years now I’ve been pondering over the weight distribution. Many heavy things, like the water and forward fuel tanks, are on the boat’s centerline, so side-to-side weight distribution is irrelevant. Other heavy things, like the aft fuel tanks and engines, are distributed equally side-to-side.

But my gut tells me that having the washer, dryer, black water tank, and three marine air conditioners, in addition to the genset, all on the port side will give the boat a nasty list. The house battery bank will be on the starboard side, but that’s not enough ballast to compensate. So I decided the Panda has to be moved to the starboard side. Needless to say, that complicates things.

Another thing that came up over the years was hearing from many boating forum contributors complaining about Fischer Panda gensets not lasting long. Being German, I expected the engineering to be good, but the general consensus I gathered was that they took an incredibly reliable Kubota diesel and made it less reliable by over-engineering it: too many sensors packed into too small a space, any one of which can shut the whole thing down. Fortunately, mine is the antifreeze-cooled, mechanical model, so there are fewer sensors and none of the proprietary digital bits that are prone to failure.

Another issue that came up was more troubling: many complain about Pandas dying with very few hours on the clock, almost always due to water from the water-cooled exhaust showerhead getting sucked back into the engine. But several sailing forums have Panda technician contributors, and every one of them stated emphatically that the problem isn’t with Fischer Panda’s design…it’s with the installers who do goofy things that condemn equipment to an early death.

So…I have a low-hour, 420-pound Fischer Panda genset that needs to be moved from the port to the starboard side. I have the gantry I built to install the Cummins engines, but it won’t fit between the engine room ceiling and the genset, so I’m going to have to get Egyptian again. And then I need to install it in perfect compliance with Panda’s owner’s manual, the most recent version of which contains many pages of examples of what not to do if you want your Panda to live a long, productive life. BUT, the genset exhaust outlet on my Roamer is on the port side, and I don’t want to drill any new holes through the Awlgrip paint job. So I had to come up with a way to safely route the exhaust to the opposite side of the engine room.

First, let’s see what the manufacturer has to say.

Fischer Panda’s installation manual mentions powerboats in passing, but all of the graphics and most of the text are about sailboats

The exhaust hose has to drop down into the ‘water lock,’ or waterlift muffler, and it should be directly under the genset. The idea is that, when the genset is shut down the entire liquid contents of the exhaust system that doesn’t drain off the boat should be able to easily fit inside the muffler. The shorter the hoses are below the genset, the less the volume of water will be in the muffler at any point in time.

Sailboats can heel over 45°, which can put some of that water up inside the exhaust manifold if the installation is done poorly and there’s too much water remaining in the system. Sailors don’t even learn that they drowned their Pandas until later when they try to fire up the gensets. But in my years driving Chris Crafts, I’ve never experienced being heeled over 45° for an extended period of time. I don’t think muffler placement is as big a deal on a motoryacht as on sailboat. But Panda says to put the muffler directly under the genset, so that’s what I’ll do.

Putting all of the parameters together, here’s what I came up with after years of pondering:

Two exhaust routing options, one with a loop and one without

Reading further in the Panda installation manual, they recommend using a siphon break loop on the raw water side. Again, this is absolutely necessary for sailboats but my gut tells me maybe not for powerboats. But the waterline on my Roamer is 10″ above the engine stringers. It will be very near the spill-over point for the genset raw water pump, and it’s just below the level of the exhaust showerhead outlet. So, again, I’ll take Panda’s recommendation and install a siphon break loop.

Elsewhere in the manual, Panda recommends gas-water separators in the exhaust system. Gas-water separators, just as the name suggests, separate exhaust gases from the cooling water used in marine exhausts. Water and steam make up a large volume in a marine exhaust system, which is why boat exhaust pipes are so big compared to exhaust pipes on land-based applications using the same engine but with dry exhaust.

Separating the water from the exhaust gas does some very interesting things: it eliminates the splashing sound of water leaving the boat with the exhaust when the genset is running. You get a nearly silent genset, which is nice when you’re at an anchorage. It also eliminates the problem of water accumulation in the long horizontal hose run I’ve got crossing from the starboard to port side.

Also, I’ve still got the OEM standpipes that let out under the waterline, which were connected to the onboard toilets in the days before black water tanks. When you flushed the marine toilets back in 1969, the contents went directly into the body of water the boat was floating in. We’re more civilized these days (in some ways), so I don’t need the standpipes for evacuating turds and can use the forward one instead as the outlet for water from a gas-water separator.

A better approach

At first I was considering Centek’s Gen-Sep gas-water separator, but I finally settled on Vetus, which also sells a plastic siphon break and plastic raw water strainers in the sizes I need.

Vetus LGS (Liquid Gas Separator) is a slick design

So, with the plan for installing the Panda genset worked out over years of pondering, I got to work. Step one involved “getting Egyptian,” using levers, a jack, 2x4s, and 1-1/2 PVC tubing to roll the genset from the port side to starboard. Check it out!

Next up in our 1969 Chris Craft Roamer 46 Refit: New Mounts for the Panda Genset