Saturday, September 21, 2013

I'm absolutely sure

I know nothing about fairing a boat hull. So with that in mind I tried a few fairing recipes with the materials I have on hand. The first one I tried is called 'blended filler' from This is a lightweight filler sold by the designer specifically for this purpose. I had a small sample I got with a test kit many moons ago.

This section of the hull is very fair already so a skim coat should give me some idea of what it's like to work with and sand.

The second I tried is a combination of microspheres (tiny glass bubbles) and cabosil (colloidal silica). It makes a very light weight filler and should be easier to sand.

The third fairing compound I tried is a readily available filler called "Quickfair" from System 3. It comes as a two part product you mix just like bondo. It's easy to work with and I've dabbled with it before. Very nice to work with.

You can see from the picture it's a bit thicker than the others. Certainly overkill for this section of the hull. I used what was left over around the bow thruster hole.

There's one particular section of the hull where the sides join the bottom where there's a pretty significant gap that needs to be faired. This was caused by the multiple layers of fiberglass all overlapping at this point. There's 4 layers of tape and six layers of fiberglass all overlapped there. At the worst I'd say there's about a 1/16" gap.

I mixed up a much heavier filler for this area. A combination of microspheres, cabosil and wood flower for bulk. Even mixing it rather soupy it's hard to spread out evenly. I used a large drywall knife and followed the curve of the chine as a guide. It'll be a bit harder to sand simply because of the bulk of it. It looks messy and it is!  :-)  That's part of the fun of building a boat I guess!

Tomorrow I should be able to block sand the test patches and see how they turned out. Standby....