1969 Chris Craft Roamer 46 Refit: Cummins Engine Install – Shaft Alignment and Front Engine Mount

I’m getting closer to having the starboard engine and gear finally aligned with the prop shaft coupler. But even with the locknut removed from the front vibration isolator and the adjuster nut completely bottomed out, I still have a 0.005″ gap between the couplers on the bottom. So the engine has to drop even lower at the front, which means the front engine mount needs modifying.

Cut off the original engine mount landing pads

Weld in a 3/4″ spacer and new landing pad (the vibration isolator is installed upside-down)

With the 3/4″ spacer welded on top of the remainder of the 3/8″ landing pad that was still attached to the mount, the bottom of the new landing pad  is 1-1/8″ higher than the original. That should give me plenty of room to reinstall the vibration isolator locknut and still have lots of adjustment to lower the front of the engine.

Ready for paint

Reconfigured engine mount looks good

Vibration isolators land in the right spot and the locknuts are installed

When I lowered the front of the engine to align the prop shaft and gear couplers, it became obvious that something was hanging up. The rear of the engine went up as the front went down!

Need more material removed from the transverse frame under the oil pan

After trimming off another 1/4″ of material from the top of the frame I now have all the clearance I need to get the couplers aligned. But first, I need to center the prop shaft in the log and lock it down.

A hole saw and some scrap lumber make a jig that maintains shaft position

Clamps keep everything locked down

Aluminum scrap wedge from the transverse frame I trimmed works as a gauge

Insert the gauge…need to raise the shaft so the gauge goes in to the mark

I tried using a dial caliper to align the shaft, but it was a real pain. The tapered gauge approach worked much better.

Right to the line on the top left

Close to the line on the top-right…split the difference by moving the shaft left just a touch

Right to the line…the shaft is centered in the log

Couplers don’t quite line up longitudinally…the rear vibration isolators need to drop a bit

Nearly perfect fit.

There’s a 0.003″ gap on the right side of the coupler, but that’s well within tolerance for the DriveSaver. I still have to drill the holes for the vibration isolator bolts and then use the gantry to lift the engine out of the way so I can coat all of the bare aluminum with Devoe 235 epoxy. When I put the engine back in place, I’ll close up that gap. The hard work on this starboard engine install is just about a wrap. It’ll be much easier doing the port side now that I know what to do.

Next up on our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install — Coating the Stringers & Final Fit

1969 Chris Craft Roamer 46 Refit: Cummins Engine Install –DriveSavers & Spacers

I’m still working on getting the engines installed while the scorching hot summer passes by. Since I’ve never done a complete engine swap before, the learning curve here is pretty steep and my assumptions about many things have been wrong. Fortunately, once I work out the process with the first engine, the second one will be a snap by comparison. 🙂

The basic problem: the top of the inner stringer isn’t parallel with the outer stringer

Rear spacers bonded with epoxy, cabosil, and atomized aluminum powder

Rear spacers ready for final sanding and installation

Epoxy thickened with cabosil and atomized aluminum powder will fill the gap between the stringer and the spacer

Rear spacer leveled side to side and bolted in place

Thickened epoxy has excellent compression characteristics, and its only purpose here is to level the spacer. In addition to being bonded with epoxy to the stringer top and side, I also bolted it through the side. The vibration isolators use 1/2″ bolts that will go all the way through the isolator, the spacer, the stringer, and a 3/8″ backing plate I’ll use on the underside of the stringer when I put it all together. The combination of the epoxy bond and heavy mechanical fasteners should keep everything together nicely and perfectly aligned.

At the front, thickened epoxy clamped to level the stringer top

The 3/4″ plywood scrap in the pic above has a strip of mold release tape attached to it so the epoxy won’t stick to it. The plywood is just wide enough to span the stringer top and land on the piece of 3/8″ aluminum angle that’s epoxy bonded and clamped to the stringer.

Voila!

The top of the inside stringer is now flat and on the same plane as the outside one

Front stringer is ready to test engine fit and shaft alignment

I’ll remove the bolts, sand, and paint this whole area white after I’m done test fitting the engine.

DriveSavers arrived!

The DriverSavers permitt me to move the engine, vibration isolators, and spacers forward enough so the rear vibration isolator bolts will clear the transverse frame under the gear; a problem I described in my last article. That’s one expensive piece of rubber, but it will also lessen vibration and electrically isolate the shaft and prop from the rest of the boat. All told, it’s well worth the price.

Next up on our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install – Shaft Alignment and Front Engine Mount

1969 Chris Craft Roamer 46 Refit: Cummins Engine Install — Spacers II

In my last article, I wrote about the second step in the process of  installing the Cummins engines into my Roamer. I came up with one plan for engine beds that didn’t work out at all, then cut up one of the beds to make spacers that should work just fine. But then I realized that the top of the stringer on one side isn’t square to the stringer upright, which complicates things just a bit. Just when I thought I’d worked around that problem, another one jumped out to bite me.

Up front, the vibration isolators are totally bottomed out

I even had to remove the locknut (lower left corner of the picture above) to lower the front of the engine far enough.

At the back, 1-1/2″ thick spacers put the engine at the right height

Perfect fit…zero gap at the couplers

But then, I checked the clearance under and around the engine…

There’s less than 1/8″ between the oil pan and one of the frames

There’s also zero clearance between the gear cooler and the top of the stringer. I need to move the engine out of the way and make some space.

Gotta love that gantry!

The gantry is absolutely the best tool I’ve ever made. Moving these one-ton engines around by a couple thousandths or a couple of feet is a one-man job.

Jigsaw makes quick work of the frame

That little wedge I cut out of the aluminum frame to make room for the oil pan will come in very handy in my next article.

Sharpie mark on the stringer marks the line for the fuel cooler

I need to cut the top of the stringer along the line I marked with a Sharpie so the fuel cooler bracket at the top of the pic above will fit between the stringers.  These coolers are notorious for causing installation headaches, and I’m experiencing that personally on my boat. Either way, it’s nothing that a gantry and jigsaw can’t fix.

Just like the front, the inner stringer isn’t square at the back

I’ll square that up the spacer when I finally install it in the next step.

The spacer is looking good…but..oh jeez.

I was so focused on the gear-to-prop shaft coupler gap, and centering the engine between the stringers, and trying to figure out what to do with the front motor mounts that are bottomed out, and the inner stringer that isn’t square to the upright frame that I totally missed the HUGE problem in the pic above.

The prop shaft coupler and gear coupler are perfectly mated, and the propeller is the exact distance it should be from the aft-most strut. But the 1/2″ bolt that will secure the rear vibration isolator to the stringer lands in the middle of the transverse frame behind the gear. That frame is welded to the engine-side of the upright stringer and the piece of aluminum angle in the pic above that forms the top of the stringer. There’s no good way to drill a hole through the stringer that won’t put the bolt and nut in the middle of that upright frame or the weld that holds everything together.

A pic from my last article shows the offending frame–how did I miss THAT???

I can’t move the engine back so the bolts clear the frame, since that would require pushing the prop shaft further out of the boat, which would put the propeller hub 2″ past the aft-most  cutlass bearing. I can’t pull the prop shaft further into the boat, because that would put the prop too close to the aft-most strut. The prop shaft can be shortened, but it’s already machined and installed. I could also have a new set of motor mounts made (which is probably what I should have done from the beginning). All of which reminds me of something I wrote about before: the butterfly effect, and how little tiny things that happened a long time ago can cause ripples in time that wind up kicking me in the balls years down the road.

I was originally going to order the prop shafts after the mechanic installed the engines, so I’d know exactly how long they needed to be. I fired the mechanic after he didn’t get the engines installed for several months back in 2012, but I’d already ordered the prop shafts based on his measurements. If only we had done things per the original plan…

While mulling over what to do about this new problem, I kept working on the spacers.

Epoxy + cabosil + atomized aluminum powder glues spacers together

Shopsmith 12″ sanding disk smooths the bonded aluminum

Nice radii on all sharp spacer corners

Good lookin’ spacer, ready for install

As I was finishing up sanding the spacers, an idea from years before came back to me. I remembered that in my original plan I was going to use DriveSavers to isolate my prop shafts from the gear. DriveSavers are basically industrial strength rubber donuts that isolate prop vibration, provide drivetrain protection in the event of a prop strike, and they break electrical continuity between the hull (via the engine & gear) and the prop shaft and prop, which is even more important on metal boats than on other hull materials. Far more important, though, was that DriveSavers generally require the engine to be moved forward or the prop shaft to be cut by about 1″ to make space for the rubber donut. In my case, they’ll permit me to move the engines forward far enough for those aft-most rear vibration isolator bolts to clear the upright frame, plus provide all of the benefits that originally convinced me they were something I needed on my boat.

We’re back in business…I think.

Next up on our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install –DriveSavers & Spacers

1969 Chris Craft Roamer 46 Refit: Cummins Engine Install — Spacers

Having finally discovered that the mounts that came with my Cummins engines would not work on the Roamer without modification, I took them to a local machine shop and had some work done. Meanwhile, back in February 2014, I had a fancy schmancy idea for engine beds. Unfortunately, that idea was based on a few assumptions that turned out to be wrong–like, thinking the engine mounts were symmetrical…silly me. Even more unfortunate is that I went ahead and bought a 25′ stick of 3/8″ angle and 1/4″ plate in 6061 aluminum and cut and welded my creation together…proving once again that a fool and his money are soon parted. But on the principle of making lemonade when life hands you lemons, I’m re-purposing the fancy engine beds as spacers between the vibration isolators and engine stringers.

Back from the machine shop, with a longer slot

My uber-precise engine centering gauge

When I first attempted to install the engines, I used a piece of tape between the stringers with a mark at the mid-point. Every time the engine touched the tape, it ripped (surprise!). The tape ended up stretching, too, so it was pretty useless as a center indicator.  So now, I use a piece of aluminum angle with a mark indicating the halfway point between the outside edges of the stringers. I put a square on the angle, line it up with the mark, and then move the front of the engine until the square is centered in the middle of the damper pulley.

The mark at the mid-point between the stringers

The middle of the damper pulley

With the new slot cut, the vibration isolator looks like it will land on the stringer

ShopSmith saw quickly cuts up expensive engine beds into useful pieces

Cutting expensive 3/8″ angle to make plate spacers

On the upside, I’ll have lots of left over aluminum to practice welding on…maybe make a shelf or two

Starting to look like a spacer

Putting an angle on the ends

I need to keep the plate out of the radius, or a gap forms between the plate and the angle

That ought to do it

3/8″ angle + 3/8″ plate = 3/4″ spacer at the front

Reconfigured rear engine mount + 3/8″ angle + 3/8″ plate (x3) = 1-1/2″ spacer

From the beginning, I wrongly assumed that the mounts that came with these engines had the slots at the same elevation. It turns out that was completely wrong–the front mounts are lower. Having never done this sort of thing before, I’m pretty much guessing how many spacers I need. After putting in 3/4″ spacers at the front and 1-/1/2″ at the back, I still had at least an 1/8″ gap at the bottom of the couplers. So I removed the spacers at the front and started dropping the vibration isolator bolts lower and lower to close the gap.

Out with the spacers at the front

In the pic above, you’ll notice that in addition to there being no spacers anymore, I’ve also bottomed out the vibration isolator. See the big nut in the lower left corner of the pic? That’s the locknut that’s supposed to go under the other nut and washer on the under-side of the engine mount. Taking it out allowed me to drop the front of the engine an additional 1/2″ and get the couplers to align. But I think it’s unwise to run without the locknut. Hmmm

Perfect fit…zero gap

And then, another problem that was right in front of me made itself apparent. If you look closely at the left side of the pic below, you’ll notice (as I belatedly did) that the angle of my uber-precise engine centering gauge is hovering above the engine stringer. rather than sitting firmly on it.

Hmmm

The original angle on the stringer is not square

It turns out that Chris Craft welded the 6061 angle to the stringer with the upright stringer plate impeding into the inside radius of the angle. This creates a gap between the angle and the plate and changes the angle between the upright stringer plate and the top of the stringer from 90° to ~95°. So, to avoid inducing stress into the vibration isolators from that 5° misalignment, I need to make a spacer that will level the stringer here. But if I do that, it will raise the front of engine, and there goes the perfect alignment of the couplers!

Dang it! Back to the drawing board!

Next up on our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install — Spacers II

1969 Chris Craft Roamer 46 Refit: Cummins Engine Installation I

Way back in May 2012, the paperwork snafu that nearly ended this refit project on a very disappointing note was resolved. With the boat indisputably mine, the first thing I did was  buy a set of lightly used Cummins 430hp 6CTA Diamonds with ZF LRM280A gears. The engine installation was supposed to happen in 2012, but Aric Euler/Chesapeake Marine Engineering–the mechanic who said he could do the installation–only showed up to open the engine room hatches, block up the floor a bit, and assemble his gantry. All through the fall and winter of 2012, we were dancing over the open ER hatches and around the gantry waiting for the mechanic to finish the job. Eventually, I had to get the gantry out of the way and close up the ER hatches so we could install the salon roof hatch even though the engines weren’t installed. In the end, I fired the mechanic and decided to DIY the install. Fast forward to 2015, and the gantry I built is ready to go and the blisteringly hot summer making it too hot to work up high in the boat. It’s finally time to get started on the engine installation.

Gantry leg and trolley

Rounded the edges of the I-beam

Ready for the chain hoist

It’s gantry time!

After blocking the floors under the gantry legs, I hooked up the chains and lifted the 2,000lbs engine and gear. Then I rolled it into rough position and placed single 4×4 blocks of wood under the vibration isolators to get a sense of what had to happen to mate the gear to the prop shaft.

No creaking, cracking, or groaning…we’re good to go

I have to say, the gantry worked very well. With it, it’s a one-man job moving this beast of an engine around.

My amateur welds are holding up just fine

Gap at the bottom between the couplers means the front of the engine is too high

This ZF gear comes with a 7 degree down angle. The prop shaft enters the boat at an 8 degree angle. So I anticipated that the engine would be oriented up at the front by roughly 1 degree. What my assumption completely failed to account for was that these engines hadn’t come out of a Chris Craft. Every big Chris Craft boat I’ve owned has had 22-24″ between the engine stringers, and the prop shafts and engines are centered between them. What I eventually realized with the engine mounts on these Cummins engines is that they aren’t symmetrical and they weren’t made for a boat with the prop shaft centered between the stringers. That’s gonna complicate things.

And then there’s the matter of that 5/16″ gap at the bottom of the gear and shaft couplers. The amount I’ll have to drop the front of the engine to close that gap turned out to be surprising.

Front inboard vibration isolator maxed out to the inside but still overhanging the stringer

Aft outboard vibration isolator maxed out to the inside and half-way overhanging the stringer

Inboard gear mount measures 7″ inside to outside

The same pattern repeats with the inboard gear mount, where the vibration isolator can’t go any further toward the engine, but part of it hangs off of the stringer.

Houston, we have a problem

The outboard gear mount measures 9-1/2″ inside to outside…2-1/2″ more than the other side. Ever have a problem that was right in front of you for years, but you never saw it…until one day when you really, really, really didn’t need any more problems?

Yup. It was kinda like that. Seriously deflating. Then again, with the paperwork snafu, the problem with “Mr. Good but slow,” the problems with Chesapeake Marine Engineering, the major theft in 2014 and the resulting problem with the windshield fabricator to replace stolen parts, and (finally) the exploding boat next door last month…I should be used to this stuff by now.

But whatever. Gotta keep moving forward. So I marked the mounts and started thinking about machine shops.

I have to remove some old engine mount material from the stringers

The gantry makes it easy to lift the engines and move them out of the way, which I had to do to get rid of the remaining weldment from the original engine mount boxes that were welded to the boat.

The vibration isolators need to land here, so the weldment all has to go away

A circular saw with a carbide blade makes quick work of removing aluminum welds

I’ll grind the high spots that remain later. For now, I need to get the front and outboard rear engine mounts to a machine shop for modification.

Next up in our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install — Spacers

 

1969 Chris Craft Roamer 46 Refit: Aft Stateroom Wall Panel Install

Since the insulated galley wall install went pretty well, I decided to try the process out on some of the pretty African mahogany panels that go around the aft stateroom porthole openings.

1/4″ African mahogany panel finished in ICA base-coat clear

I added a cleat to secure the leading edge of the new panel to the bathroom wall

I cut out notches to make space for the hull frames on the transom

As you can see in the pics, the back-side of the panel is still bare wood. The plan is to get the final fit right, then coat the backs and all edges with epoxy. The ICA coating on the face will allow me to wipe off any wet epoxy with an ethanol-soaked rag. With the panel fitting to the hull and interior wall, the next step involved the missus holding the panel in place while I marked the porthole openings from outside.

Cutting out the porthole openings

Two down…

Good test fit at the transom and window cut-outs

African mahogany panel-to-panel fit is good, too.

Epoxy coating and insulating the back of the panel

On the galley panel I installed recently to test my insulation plan, I used 3M spray-on contact cement to adhere the Buffalo Batt polyester nonwoven fabric insulation to the cured epoxy protecting the back of the panel. I figured I could save a step by applying the insulation as I roll on the sealing epoxy coat. The missus was a big help putting her craft skills to work cutting the insulation to size, leaving room for the attachment points.

Insulation applied to port and starboard panels, then pressed gently together until the epoxy cures

Epoxy drippage from edge sealing was caught by tape

Tape comes off clean, leaving the edges sealed with no residue or stains on the African mahogany

If I hadn’t already finished the front face with ICA base-coat, the epoxy would have bled under the tape and stained the pretty mahogany.

Ready for installation

Nice!

The dead air cavity between the insulated hull and the insulated interior panel

The insulation gurus all say that dead air space between the outer and inner layers of insulation significantly adds to insulating properties of the material. Hopefully, this approach is worth the effort.

Before I permanently install these panels, I need to assemble the portholes and get some other things done. So for now, the panels are sitting in place, out of the way, covered in plastic, and protected from abrasion. With the heat of summer making it too hot in the tent to work up top-side, I’m getting myself into the engine room next.

Next up in our 1969 Chris Craft Roamer 46 Refit: Gantry Time II!

1969 Chris Craft Roamer 46 Refit: 1st Galley Plywood Install

Back when I was first thinking about insulation, I figured I’d get the best bang for the buck with spray foam (R7 per inch) on the hull and cabin top and 1-1/2″ thick Buffalo Batt polyester nonwoven fabric (R3) on the backside of each plywood panel that faces the hull. That combination should stop condensation dead and keep conditioned air in the living spaces, where it belongs. With the spray foam done, I decided to make the plywood stack smaller and install a panel.

1/4″ marine doug fir ply, cut to size and epoxy sealed on the back-side and edges

Need to square away some wiring and install a couple more cleat attachment points

The big wire loom on the right is the main feed shore power line that will go to the isolation transformer in the V-berth.

3M contact cement ought to hold the Buffalo Batt in place

Rolling out and measuring the polyester nonwoven fabric

This stuff is a LOT nicer to work with than fiberglass. No itch, and since it’s a fabric it doesn’t lose fibers.

The polyester nonwoven fabric needs to fit between the cleats the panel will attach to

Hose on the contact cement

Press the insulation into position, leaving space for the cleat attachment points

Buffallo Batts are all in place

Shore power main feed and stbd running light wires are secured out of the way

Dead air space inside the cavity between insulation layers reportedly yields best results

Polyester nonwoven fabric breaks for the cleats

Nice fit! Done!

So, the lesson learned here (and in a lot of other instances) is that cutting the panel, slapping some primer on the back side and edges of the panel, and installing it (like Chris Craft did originally) would have taken maybe an hour. Doing it the way I did took a day, including an overnight curing process for the epoxy. Multiplying that out over the entire boat, I figure I’ll  have a literal month of Sundays added to the time the project will take to complete with this approach. It better be worth it. In any case, this one panel install gave me some ideas for how to improve the process that I’ll try out on the next panel.

Oh, and if anybody’s interested, I’ve got a low-hour set of Cummins 6CTA exhaust risers that I just listed for sale.

Next up in our 1969 Chris Craft Roamer 46 Refit: Aft Stateroom Wall Panel Install.

1969 Chris Craft Roamer 46 Refit: Spray Foam Insulation

After a whole lot of time prepping the boat for spray foam insulation, I decided DIY Tiger Foam was the best bang for the buck. I initially intended to have a pro come out and do it, but I couldn’t find one who had experience foaming a boat. There was also a wide gap between estimates: $2,000 from one contractor vs $3,500 from the other. Tiger Foam was $1,350 for two 600 board feet kits, including shipping, and its E-84 fire rating is better than what the pros were offering. Plus, I like the challenge of DIY so…

1200bf of Tiger Foam

Moving big things away from the hull

After moving the plywood stack up against the galley bulkhead and the track saw table to the center of the salon, I started taping the place up the 3M hand masking film.

Ready to spray foam

Plastic and cardboard protect everything in the aft stateroom

Overhead panels got taped to protect the ICA clear-coated African mahogany

under-side of the side decks are clean and prepped for foam

I taped off the vent hole up above before spraying began.

V-berth taped off

Stem to stern, she’s ready for foam!

Having read all sorts of comments, seen tons of youtube videos, and read the manual front-to-back several times, I knew for a fact that spray foam is temperature sensitive. There are all sorts of warnings about application when it’s too cold, which yields a foam mix that may not rise at all. But there are no warnings at all about application when it’s too hot…which pretty much describes this whole year since two days after winter ended. I mean, we went straight from snow to hot–it was 75 degrees two days after the last snowfall, and it’s been over 85 on many days pretty much since late April.

So, on the day I sprayed foam, overnight temps never went below 79. That’s good, because 70 degrees is the minimum recommended tank temp for the foam. But by 10am, it was over 100 inside the tent up topside. The tanks were on the warm side when I finally brought them inside the boat, suited up, and started spraying. What they don’t show you in all of the videos is the amount of foam that rains down from above–what a mess!

That said, the first tank didn’t quite get the coverage I expected. But I attribute that mostly to the tank being too warm. There’s a bit of a learning curve, too, with respect to petroleum jelly you use on the nozzles (hint: use lots, and keep reapplying it or the foam doesn’t exit the nozzle smoothly). It also takes a bit to figure out which nozzle to use and how hard to pull the trigger (hint: use round nozzles and a very low application rate to frame out the perimeter of very box section between frames, then the fan nozzle and a higher application rate to fill in the middle). There’s also the eye protection problem.

It was 90+ in the boat and sweat running in my eyes made the job that much harder. The goggles I used kept fogging up on the inside, and the spray foam was coating the outside. After ten minutes, I was basically spraying blind. Swapping out the old goggle lenses for new, the same pattern repeated. And unlike spraying in a house, like they show on all the videos, all of the nooks and crannies of the hull and deck framing make it especially important to be able to see what you’re doing.

But it worked. It’s not perfect, but I got foam!

3 layer, full-depth coverage in the overhead of the aft stateroom head

Fairly uniform coverage on the aft stateroom head walls

Aft stateroom head

Aft stateroom

Spray foam over original Chris Craft bitumastic coating should keep condensation down

Foamy goodness inside the hanging lockers

This locker has the new aluminum deck outboard, so that aluminum didn’t have any of the OEM bitumastic. I laid the foam on heavy in here, in three layers yielding 2″ thickness minimum.

More foam in another locker

Note the slightly yellow foam at the center of the overhead above–that’s from the first tank that was a bit too warm. It expanded well, but perhaps not 100%.

Salon overhead foamed in

Condensation-proof AND bullet proof salon top

Hull side and under-side of the side deck

V-berth overhead

When I finally wrapped up, it was late after a looong day.

Next up in our 1969 Chris Craft Roamer 46 Refit: 1st Galley Plywood Install

1969 Chris Craft Roamer 46 Refit: Prepping the V-berth for Foam Insulation

One-by-one, I’m knocking out the honey-do list toward getting the boat splashed this fall. There have been some set backs, like the ongoing windshield frame fiasco, that might make it impossible to splash this year. But I’m still going full speed ahead in the hope of getting back on track, hopefully before I run out of steam.

With the aft stateroom all prepped for insulation, next I’ve got to do some things to get the V-berth ready for foam. And in getting that stuff done, I found a surprise left behind by a woodworking sailor who worked on the boat for a couple of months in 2012 and sold his services as “good but slow.” I found a mess Mr. Good-but-slow left behind when I was cutting the interior panels for the galley windows, and as I’m revisiting each part of the boat that he touched, it seems that all of his work left something to be desired.

The v-berth concept

V-berth major walls installed by Mr. Good-but-slow and wrapped in cardboard

In the pic above, I pulled up the v-berth floors to vacuum out the bilge one last time before fastening everything down. There were some surprises awaiting me as I pulled up the floor panels.

Mr. Good-but-slow’s patented “floating wall” system

When the woodworker initially installed the wall, he had the panels bolted to the hull frames but not connected to the deck frames overhead. Instead, they were held in place between a series of mahogany blocks that sort of pinched the panel while permitting limited up and down movement. I’d given him wide amount of discretion on how to accomplish my concept for the v-berth, so I wasn’t upset with the approach. And I understood his theory that an overly rigid structure can catastrophically fail, so permitting some degree of movement can be a good thing, as in the case of viscous couplers used to make bridges earthquake-resistant. I also knew from talking to a former Navy ship engineer that in underwater mine testing of fiberglass hulls, the engineers determined that FRP joint failures were prone to happen when explosions happen nearby. But, I pointed out to Mr. Good-but-slow, an FRP hull to engine stringer joint is a different beast than 3/4″ marine plywood bolted to an aluminum hull and deck. And in any case, I have no intention of running my boat in waters containing mines. Having a bullet-proof cabin top is one thing…I don’t need mine-proof v-berth walls!

So, Mr. Good-but-slow followed my explicit instructions and bolted the v-berth panels to the mahogany that was bolted to the overhead deck frames. What I didn’t know was that he’d left the bottom end of the panels free-floating, too. In the pic above, you can see that the panel is sitting firmly on the floor framing but it’s fastened to nothing along the bottom. When I removed the two floor panels, I discovered that he had used the same pinch approach as he used on the top!

Three large mahogany blocks bolted under the floor frames

I stared at the three blocks in the pic above for a while, trying to figure out what their intended purpose was. In the end, I was stumped and decided Mr. Good-but-slow might have wanted them to support the center floor section (which lifts out), but the blocks are under the floor frames–they don’t have a rabbet cut out so the edge comes up to the top of the floor frames. Plus, they barely stick out far enough to support anything, even if they were high enough. Finally, Mr. Good-but-slow knew I was using rounded corners on the walls, so it’s unclear why the transverse wall he installed comes out so far that the longitudinal wall that will attach to it cannot land on the floor frame.

Geesh. Time to get busy.

Everything glued and screwed together

I was too busy to take step-wise pictures, but the shot above captures pretty much everything. First, I cut mahogany blocks and used epoxy to glue and screw them to the mahogany blocks Mr. Good-but-slow installed. I installed them so they’re high enough and stick out far enough to support the center floor panel. Next, I wetted out both sides of the lower end of the wall panel and saturated both floor panels along the end grain with epoxy. Then I used my Kreg Mini Jr pocket hole jig to drill screw holes, and I applied epoxy thickened with wood flour and cabosil along the joints, Next, I fastened the floor panels to the wall panel glue joint using pocket screws, which pull the whole assembly together tightly, and I fastened the floor panels to the aluminum floor frames. Next, I cut out a bit of the center floor section that will support the longitudinal wall, and glued and screwed it in place. Then, finally, I installed the solid mahogany corner piece that’s pre-coated with ICA basecoat clear.

The overhead plywood finally gets installed

I started the day only planning to install the overhead plywood in the v-berth, then get on with other projects. Instead, it was nearing the end of the day when I finally got the overhead piece installed.

Epoxy stains on unfinished plywood won’t matter

The v-berth wall finishes will be a combination of off-white painted surfaces, ICA-coated natural mahogany, and Whisper Walls fabric. Because there’s limited light in the forward compartment, we decided there should be a lot of surfaces in white. The walls here will be finished white or covered with foam-backed white fabric, so the epoxy stains on the okume ply aren’t a concern.

Done!

With the v-berth finally ready for spray foam insulation, the next step is waiting for the foam to arrive.

Next up in our 1969 Chris Craft Roamer 46 Refit: Spray Foam Insulation

1969 Chris Craft Roamer 46 Refit: Aft Stateroom Head Ceiling

There are many, many things going on all at once as I work through the issues on my helm station windshield frame. Getting the aft head done is one of those multi-step processes, and everything has to get done in a certain order. While we were getting the walls fiberglassed and faired, we’re also cutting and fitting plywood panels to use for the ceiling. In preparation for spray foam insulation, I also removed the original fiberglass insulation from overhead. As you can see in the pics below, there’s some of the tar-like adhesive Chris Craft used to attach the fiberglass remaining. But, according to the spray foam literature, the substrates don’t have to be perfect so long as they’re clean and well adhered.

Cheap luan ply makes good patterns

Breaking down a sheet of 1/4″ marine ply

My EurekaZone EZ-One woodworking center and track saw make it pretty easy to break down large panels. There’s no way I could do this with a conventional table saw.

Plastic guide strip shows exactly where the blade will cut

The track saw guide strips stick out a bit when new. You do the first trimming cut on scrap wood down the full length of the track, which cuts the plastic exactly to the edge of the saw blade kerf. Taping the guide before the trimming cut makes for a cleaner cut. From that point on, just align the guide strip edge with the start and end points of the cut.

Clamps on the underside hold the track tightly to the wood

Final cuts on the ceiling panels

After checking the fit of the panels in the aft head, we moved them up to the aft deck and applied fiberglass to what will become the inside surface.

FRP on the ceiling panels

We then applied home-made fairing compound when the epoxy resin became tacky

We’ll sand the fairing compound later and applying Alexseal 202 fairing compound, which is reportedly the best stuff to use in showers. Then we’ll sand the Alexseal and apply Buffalo Batt insulation (R3) to the backside of the panels, then glue and screw the panels into place. But first, in preparation for the spray foam insulation, I need to get all of the African mahogany pieces that will be attached to the overheads cut and installed. Word has it it’s much easier to install bulkheads and then spray foam than to spray foam and remove strips of it to install bulkheads.

Next up in our 1969 Chris Craft Roamer 46 Refit: Cutting and Installing Overhead Mahogany Plywood