1969 Chris Craft Roamer 46 Refit: Prepping and Priming the Aft Enclosure

My painter, fairing crew boss, and chief Boatamalan informs me that there are exactly seven “paint days” remaining before our Roamer 46 is painted with the shiny, non-skid and accent stripes…top to bottom.

Seven paint days… After five years, I’m ready for it.

Of course, since  we only work on the boat on weekends seven paint days works out to be about a month. So, it looks like we’re not going to make the end-of-May 2013 target, but we’re not far off. Before the paint days can begin, though, we’ve got to finish up the priming. And the last section of the boat that remains unprimed is the new (in 2008) aluminum aft deck enclosure.

Last weekend, we got ‘er done.

Rounding welded corners and sanding off mill scale

It was nice to see the boat in natural sunlight while I was transforming Tent Model IX once again. The aluminum to FRP hardtop fillets turned out nice.

This vertical welded seam creates a subtle but hard corner on the outside of the aft enclosure panel.

Even with the seam weld ground down and the panel sanded, there still is a bump you can easily feel.

If you can feel a bump, it’ll really stand out when it’s painted with “the shiny” AwlCraft 2000 Matterhorn White.

We mixed up some fairing compound and laid it out on both sides of the seam high spot.

I’ve found that US Composites 635 epoxy and their 4:1 hardener (their fastest one) takes a lot more time to cure than West System. Production time costs, so at this late stage of the game we’ve switched to West System and their fast hardener so we can mix up epoxy + cabosil (40%) + 3m microballoons (60%) fairing compound, apply it and sand it just an hour or two later.

Another lesson learned: buying a 55-gallon barrel of West System at the start of this project would have been significantly cheaper and faster than ordering US Composites in multi-gallon kits. If I knew when the project started what I know now…

While the fairing compound cured, we kept attacking the aluminum with sanders.

All of those nooks and crannies are a PITA! Once the sanding was done, I hit all of the corners, seams and welds with a wire wheel on my Makita sander. Meanwhile, the guys longboarded the fairing compound we applied around the welded seam on the aft panel.

With all of the longboarding, sanding and wire brushing done, we applied Alumaprep and then Alodine.

Next came the Awl Grip Max Cor aluminum primer.

The green stuff is Awl Grip Max Cor.

The vertical line of Max Cor is where just a hint of a weld high spot remained in the aluminum, but the guys faired it out so well that I can’t feel any high spot at all.

Max Cor is the replacement for the previous Awl Grip aluminum primer that was available when we first got the boat. The old stuff was yellow and didn’t stink anywhere near as bad as this new stuff, which is also 25% more expensive. Everybody in the tent had space suits, full face masks and VOC filters on, and the exhaust fan filters turned green in no time!

We didn’t fully prime the entryway with Max Cor because it’s actually coated in fiberglass.

The welds for the aft entryway are on the inside of the panels, which leaves an exposed seam without welds on the vertical surfaces you see here. We cut the door out after welding it all together, so the door and the opening would hold their natural, curved shape. Welding the exposed seams on the vertical threshold pieces would put a lot more heat into the panels and, because it’s aluminum, might cause warping — the curved door that fits the curved panel might not anymore.

We don’t anticipate any movement on the seams, but just putting fairing compound into a seam crack would just beg for the compound to crack in the future. So, we mixed up some West System thickened with 404 adhesive and wetted out the aluminum before applying wetted out 12oz fiberglass cloth over the seams in both vertical threshold panels.  The 404 keeps the fiberglass firmly attached to the aluminum, and the fiberglass will not crack the way filler might.

That’s a lotta green.

Fillets at every joint and seam.

The challenge was–how to apply Alumaprep and Alodine (both acids) and water to the bare aluminum without having any of the liquids wick in between the stitch welded aft enclosure framing and exterior panels. If any liquids got into the seams, there’s no way we could prime within the window stipulated on the Awl Grip product labels. After talking about tape and a few other ideas, we settled on mixing up more homemade epoxy fairing compound and putting fillets at every joint and seam. It was time consuming, but the fillets preclude liquids from entering the seams, and the primer film is now continuous over the entire aluminum surface, inside and out. Since aluminum oxide can travel very far under primer when there’s a break in the film, this approach should ensure a very long life sans corrosion for this enclosure and its paint job.

Nice fillets at the welded panel joints.

The aft-most panel turned out very nice and smooth.

After two coats of Max Cor, we waited 1-1/2 hours, then broke out the Awl Quik and a five-gallon pressure pot paint rig.

That hard welded seam has just sorta magically disappeared.

The fairing crew from Weaver Boatworks that’s moonlighting on weekends doing my boat…they sure do nice work.

This is turning out just like I envisioned with my cardboard mockups in 2008!

And with that, the aft enclosure was in primer!

I’m all giddy! 🙂

Next up on our 1969 Chris Craft Roamer 46 Refit: Fillets & Final Touches on the Aft Deck Enclosure