Since I de-SMIB-ified the helm station door, it was time to prep the aft enclosure for primer. Aside from all of the nooks and crannies associated with the framing on the inside, which will make sanding a challenge, I also want to mechanically fasten the top of the enclosure to the hardtop in more places. With screws holding it together on the interior side, I’m thinking a nice, heavy layer of 1708 fiberglass on the exterior seam will be good, especially if we do fillets as we have elsewhere on the boat.
We use combinations of 36, 60 and 80 grit to knock the mill scale and other residue off the aluminum plate, which also provides a good mechanical bond for the primer.
Epoxy bonds to the fiberglass hardtop well enough, but we add West System 404 adhesive filler to the resin we use to wet out the aluminum. This approach promotes adhesion and reduces the possibility of the fiberglass popping off the aluminum down the road, which (I’m told) it tends to do without adhesive in the epoxy. We also push the thickened epoxy into the joint to eliminate gaps between the aluminum and FRP hardtop and make an overall stronger bond.
This is the same approach we used on the cabin top and elsewhere. It really is a time saver.
We’ll let the epoxy cure overnight, then sand and fair again on Sunday.
Next up in our 1969 Chris Craft Roamer 46 Refit: Priming the Decks