Fly Fishing Traditions: Kingfisher Drift Boat - Prepping the Hull for Painting

It's time to get ready to paint the hull, I've done about all I can do on the interior of the boat and it's time to work on the outside for a while, This will entail flipping the boat upside down to work on. To get ready for painting the hull I had do do quite a bit of work prior to getting it done.

Getting a little ahead of myself. Here's the hull after it was painted.

The critical path went something like this

Flip the Boat over
Sand or use a cabinet scrapper to prep the bottom of the gunnels
Flow coat the underneath side of the gunnels once they are prepped.
Run a fillet of epoxy peanut butter at the junction of the gunnels to the sides.
Run another flow coat of epoxy on the underside of the gunnels and coat the fillet
Sand and flow coat the rounded transom with it's last coat of epoxy
Finish sand and the underside of the gunnel, the sides and the rounded transom progressively to 220 grit.
Mask off the gunnels and the rounded transom to get ready for painting the hull.

Flipping the Boat

I enlisted the help of three friends to flip the boat over. It has been residing right side up on a 4' x 10' table with rolling casters. The first task was getting the boat on the floor of the shop. I worked the boat to one end of the table. Imagine launching a boat from a trailer. Once I got the stern on the floor we just lifted the bow and slid the table out from under the boat. I had furniture blankets on the floor. The gunnels are coated with at least two coats of epoxy but I still wanted to have blankets under anything on the boat that contacted the floor. The steps went sort of like this.

Place furniture blankets on the floor in position so that as the boat is lifted up on one side and supported on one gunnel (half-way flipped) the blankets are under the spots of the center section of the gunnel. Pretty much in the center of the boat at the oar locks.
I also placed furniture blankets that are folded up in multiple layers under the stem and transom so that when it is flipped it is cushioned under these areas.
Two people are on one side of the boat and two are on the other.
The boat is lifted by two people so it is resting on one gunnel, basically half flipped. The other two people help support the boat in the vertical position.
It is then tilted over to the upside down position and supported by the two people on the other side of the boat.
Once the boat is flipped and is resting on the floor, lift the bow up and slide extended sawhorses, about 5 1/2' long, underneath so the bow is supported by both gunnels. Cover the tops of the sawhorses with padded materials. I used old towels.
Repeat the same procedure for the stern of the boat.
The boat should now be flipped upside down and resting on the padded extended sawhorse.
Ready to go to work.

Prepping the Gunnels and Rounded Transom for Flow Coating

One problem when flow coating the gunnels when the boat is right side up, is that it is almost impossible not to have drips or runs of epoxy on the underneath side of the gunnels. I found that the best approach is to use fast set hardener in small batches and tend it until you can't mess with it anymore. Even doing this I had some runs and drips. The best way of getting rid of these drips and runs on the underneath side of the gunnels is to use a cabinet scrapper. The scrapper removes the material you need to remove quickly and efficiently. Once the runs and drips are knocked down I then final sanded them by hand. I used 120 grit followed by 150 grit followed by 220 grit. They turned out pretty darned nice. Note: Remember to use cabinet scrappers to do the dirty work.

I finish sanded the rounded transom next to get it ready for its last flow coat of epoxy. Most of the rounded transom will not get painted and the mahogany plywood will be varnished.

This photo shows the detailed and sanded underneath side of the gunnels and the epoxy fillet at the junction of the gunnels to the sides.

Flow Coating the Gunnels and Rounded Transom

Once the underneath side of the gunnels were sanded it was time to flow coat them. I masked off the gunnels at the center of the 1/4" round over all around the boat. I didn't want the epoxy to run back down the face of the gunnels. I also flow coated the rounded transom. This is basically the last of the flow coating of epoxy on the entire boat. Wow, it's been a long time coming.

Sanding the Sides, Gunnels and Rounded Transom

Now that the flow coating was completed on the hull it was time to finish sand the entire exterior of the boat. I used a random orbital sander and sanded the sides to 220 grit. Being that the rounded transom is curved I used a flexible pad and hand sanded it down to 220 grit. I hand sanded the underneath side of the gunnels to 220 grit.

Clean Up and Masking

The last steps were to vacuum all the surfaces and then wipe the surfaces down with acetone and then start masking. Once the surfaces were vacuumed, I used the two rag method for prepping the surfaces. One rag is used to wipe down the surface and a clean rag follows.

Now it's masking time. I used 1/4" wide green masking tape that is used in auto body shops to mask the line that I will paint to. Once the 1/4' tape is laid down I use a masking machine with 3M 3/4" blue tape and 12" wide masking paper that comes on a roll. I taped off about 12" from the 1/4" green tape along the gunnels, the rounded transom and the Linex material that wraps up the sides about 4".

After the sides were masked to isolate the portion of the boat to be painted I checked to see that the tape was set tight at the paint line.

You can see the green 1/4" wide masking tape at the line to be painted. It is taped to the Linex that runs 4" up the sides. I then used a masking machine to finish up.