1969 Chris Craft Roamer 46 Refit: Forward Fuel Tank Tabs and Insulation

With the galley floor supports installed, next I’ve got to weld some tabs on the forward fuel tank, then put the tank in, install the galley floors and insulate them.

AlphaTIG 200 maxed out on 110vac

2016 AlphaTIG 200DX maxed out on 110vac

One cool thing about this AlphaTIG is that it can run on 110 or 220 volts, and it auto-detects what’s coming in. All you have to do is use the supplied 110v adapter cord (or not, if you’re using 220). On 110, the maximum it can put out is 149 amps, which is not a lot for aluminum work. But it’ll be fine for this relatively thin stuff. I’ve got the machine set to AC high frequency output, with the pulse maxed out at 200hz. AC balance (cleaning action) is at 35% because this is dirty, old aluminum. Even lightly ground down and wiped with acetone, there’s bound to be some gunk in the weld area, and aluminum is very picky. I’m also using the finger switch on the torch rather than the foot pedal. With the exception of a couple of practice beads, this is the first time I’ve used the finger switch. I think I prefer the ability to adjust the power with the foot pedal.

Ready to tack

Ready to tack

I originally intended to use straps to secure the tank in its cradle. But now that I’ve got my new welder, it occurred to me that welded on tabs would be better. The tabs will have bolts going through them that attach to corresponding tabs on the tank cradle.

Tacked on the corners...ready to try and weld!

Tacked on the corners…ready to [try and] weld!

Not exactly a stack of dimes, but I believe it'll be fine

Not exactly a stack of dimes, but I believe it’ll be fine

When I practice moving the torch and nothing else, my hand movement is pretty smooth. When I practice feeding the filler rod and nothing else…I’m getting better at it. But when I try to do them both at the same time, both become very unsmooth. Still, my welds are looking lots better than what the “professional welder” did. I’m sure they’ll hold up just fine.

Setting up to weld the tank tabs

One down, three to go

It’s nice to be able to open the bow seat window for ventilation. Now if only I wasn’t in a tent. 🙂

Once the tabs were welded on, I drilled the bolt holes and re-coated the tank sides and bottom with Devoe 235 epoxy.

Fuel tank and muffler platform coated with Devoe epoxy

Fuel tank and muffler platform coated with Devoe epoxy

The other muffler platform

The other muffler platform

I’ll be welding in the muffler platforms soon so I can get the exhaust system wrapped up. But while the epoxy is curing on the tank, I got to work on the galley floor insulation.

Cutting Buffalo Batt insulation

Cutting Buffalo Batt insulation

Cut wide enough to span the galley floor framing

Cut wide enough to span the galley floor framing

First, use monel staples to secure the insulation to the frames

First, use monel staples to secure the insulation to the frames

With the round water tank in place, there’s no way to put this insulation in once the floors are installed. The insulation’s got to go in first.

Lightly tensioned insulation

Lightly tensioned insulation

The batts stick up just slightly proud of the framing

The batts stick up just slightly proud of the framing

The insulation needs to contact the floor once it's installed

The insulation needs to contact the floor once it’s installed

Wet out the under-side of the galley floor with epoxy

Wet out the under-side of the galley floor with epoxy and install while it’s still wet

That black, tar-like material Chris Craft used to glue the original fiberglass batts in place is funky stuff. Most of it came off when I removed the fiberglass. I took a scraper to the stuff that remains and was able to remove some of it. I assumed that what wouldn’t come off by itself or with a scraper was securely attached to the plywood. But when I started rolling on epoxy, gobs of the stuff would come off on the roller! So I ended up using the scraper to remove epoxy-coated tar where it came loose. Better to have it come loose now than later, I suppose. But just in case, I applied more staples to secure the new insulation to the plywood to augment the epoxy bond.

After screwing down the floor panel, more monel staples secure the batts

After screwing down the floor panel, more monel staples secure the batts

Next, the tank goes back in its cradle

Next, the tank went back in its cradle

Good looking tabs

Good looking tabs

I also insulated the bulkhead and back-side of the V-berth steps

While cutting the next insulation panels, I also insulated the bulkhead and back-side of the V-berth steps

Insulating the under- and back-sides of each panel adds a lot of time to the process, but I think it will ultimately be worth it. I’ve heard from other metal boat owners whose boats weren’t well insulated that it can be horribly uncomfortable (or prohibitively expensive) keeping the boats cool in summer and warm in winter. The R3 insulation value provided by the Buffalo Batts should help keep the air conditioned/heated space inside separate from ambient temps outside.

Galley floor framing goes back in

Galley floor framing goes back in

Once again, wet out the under-side of the floor panel with epoxy

Once again, wet out the under-side of the floor panel with epoxy

Done!

Done!

That’s a wrap for the forward fuel tank and galley floor. Now I can move my track saw from the salon to the galley, then move the plywood pile sheet-by-sheet to the other side of the salon so I can get to the mahogany panel I need for the last wall of the V-berth head (AKA the Throne Room).

Next up in our 1969 Chris Craft Roamer 46 Refit:  Final “Throne Room” Wall Panel

5 comments on “1969 Chris Craft Roamer 46 Refit: Forward Fuel Tank Tabs and Insulation

  1. Colin says:

    Wont those buffalo batts get damp and moldy?

    • 1969roamer46 says:

      Hi Colin.
      If you click the links to the earlier articles on insulation, I go through the merits of Buffalo Batts. It’s a woven polyester that’ hydrophobic, meaning water doesn’t like it. 3M Thinsulate is similar (using polyester and polypropylene, or polyolefin) and is used on Weaver Boatworks $8~10 million sportfishermen. I’ve never heard of them having a mold problem. Time will tell, but hydrophobic materials generally don’t harbor mold.
      Cheers,
      Q

  2. Peter Hitchcock says:

    For a first go that welding looks dam fine… well done…

    • 1969roamer46 says:

      Thanks Peter! I’ve been welding steel stick and MIG as a weekend warrior for a few decades, but only started on aluminum MIG two years ago. The TIG is a whole ‘nother beast, but I’m slowly getting the hang of it.
      Cheers,
      Q

  3. John Casteel says:

    Coming along nicely. Great to see your progress.

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