Kingfisher Drift Boat Build - Sanding, Sanding, Sanding

I was warned that building a Stitch and Glue drift boat was sanding, and then some more sanding and then you guessed it, more sanding. The other thing is that you are sanding epoxy, which is a pain in the A--.

Once you flow coat epoxy you need to sand it flat.

The question is how flat?

Like:

• For exposed areas like the inside of the sides of the drift boat that means really flat. You will be varnishing over top of the epoxy later and any flaws will show through.
• For the exterior sides if you are going to paint them with marine paint, You need this really flat.
• For interior wood parts that will receive a varnish finish. You need them really flat.
• For the drift boat bottom, Not so flat as it will get painted with truck bed liner.

You have to pick your battles. Such as the interior of the sides gets truck bed liner up about 10" from the bottom so don't knock yourself out on the bottom 8 inches of the interior side panels. Get the picture?

So how do you get set up for sanding?

First off using a good 1/2 sheet sander works really well for getting flat finishes. I purchased a Makita half sheet sander and it has made sanding a lot easier. You have to sand down through the epoxy imperfections to get the surface flat. The paper for a half sheet sander is a lot more cost effective than hook and hoop disks. 

I use my 5" random orbital sander for the areas that don't need to be really flat. Like the bottom of the interior, The parts of the boat that will get painted with truck bed liner. 

All the money pieces, the exposed clear coated mahogany, the gunwales, the knee braces, the seats, need to be as perfect as you can get them. You guessed it a lot of sanding.

Once the epoxy flow coat is hard I hit it with 120 grit, then 150, then 180 grit and finally finish with 220. This works pretty well. The 120 cuts pretty aggressively. It gets smoother and smoother as you get finer with the grit.

Sanding epoxy takes lots of sandpaper. I pre-cut all my sheets and have them ready to go before I start sanding. I've been sanding my side panels and to give you an idea the panels are about 2 feet wide and I can sand about 4 lineal feet before the paper starts struggling to cut. So that's about 8 sq, ft max per 1/2 sheet of sandpaper. I use more of the pieces of the coarser grits. as I'm cutting through the imperfections to get the panels flat.

The other thing is you have to have a sander that you can hook up a hose to a vacuum. This is mandatory. I have an old Craftsman vacuum that I can hook up to most any sander with a special adapter. You have to contain the dust. You don't want to be breathing it.

So guess what I'll be doing tomorrow? Sanding!