1969 Chris Craft Roamer 46 Refit: Sandblasting Inside & Out

Fast forward to August, 2008, and we had long decided that the Roamer would need far more than just “engines and a paint job.” We were in it for the long haul, though, and figured that if it was worth doing, it was worth doing right.

For the engines, that meant converting from gas to diesel. For the paint, which had been redone decades before in marine enamel, it meant stripping it all down to the base aluminum hull. On the interior, most of the paint and bitumastic hull coating from the keel up to 3′ of depth had turned into a greasy slurry in the bilge. This happened because the salon hatch had failed, allowing rain water to fall into the salon and, from there, into the bilge. The bilge would fill to the point where the main seacock sight glasses had broken and drain out from there. Constant submersion under 3′ of water and oil from the engines eventually separated the bitumastic from the hull. Removing the water from the bilge left behind that nasty slurry, but it was impossible to clean it all out. The epoxy barrier coating we intended to use wouldn’t stick to the residue that was left behind.  The solution was to sandblast the boat inside and out.

We first tried stripping the exterior with a grinder.That proved to be both slow and inadequate–the epoxy barrier coat stipulates a sandblasted surface.

Having already removed the hardware, we carefully removed the toe rail.We’ll use them as patterns when we make the new ones later. There were several places under the toe rail where the factory barrier coating had failed, and white powder (Aluminum Oxide) was abundant.

We found that taking the surface down to the hull was unnecessary in many places.The original fairing compound was extremely heavy in spots, so we simply removed the paint, primer and fairing compound until we got to solid material. In some places we went all the way to the aluminum hull, but perhaps 50% of the hull didn’t need to go down that far.

Blasted3August7_2008

BlastedAugust7_2008

Almost there!

DSCN4090

This shot captures the issues we were dealing with.The rub rail shows some aluminum wasting where water got under the primer. That area was blasted clean, removing all of the Al2O3. The area below the rub rail shows bare aluminum and the primary Chris Craft hull mastic, which is like concrete and VERY stable (i.e. not cracked). The lighter fairing compound at the turn from the hull side to the rub rail was prone to cracking, but this area was solid and still very well attached to the hull base metal.

On the inside of the boat, all of the nasty bitumastic, oil, aluminum oxide and other goo had been replaced by hundreds of pounds of volcanic dust from the Farrow System sandblaster.But with the sandblasting debris removed (a process that took a very long time and repeated cleaning), we were left with a good surface for the epoxy barrier coat.

95 percent clean stringers

DSCN4078

DSCN4082

There were certain areas the sandblaster missed, but with the bitumastic gone we were able to do the final clean up in these areas using Alumiprep and Alodine. It was a long, nasty process, but the final product was exceptional.

DSCN4087

DSCN4088

DSCN4089

dscn4161

With the sandblast dust gone and the entire bilge treated with Alumiprep and Alodine, she was ready for barrier coating.

While sandblasting clean up continued, a new 420 gallon fuel tank arrived.This will fit in a cradle that we built over the keel, so it will be center-line under a queen-size bed rather than having two tanks outboard under Ozzy and Harriet bunks in the original configuration.

Next up in our 1969 Chris Craft Roamer 46 Refit: Turning Sheets of Aluminum Into Side Decks.

Advertisements

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s