S&G Petrel - Fillets and Sanding Them

Submitted bykoineboy onWed, 10/03/2018 - 11:38



I'm building the Petrel S&G kit, and I glassed the hull successfully but not without several "Oh no!" moments.

I wasn't fast enough to lay fillets down the length of the boat and get the cloth in place and wetted out before the fillets kicked. I'm slow.

I want to put in the fillets one day and glass another. If I lightly sand the fillets, can I do this?





Etienne Muller

Wed, 10/03/2018 - 16:03

Stem filletYes. There is no reason why you cannot do this. I do it when I am filleting my inner stems. The smoother your fillets are, the easier it will be to sand them.

If I can, I like to do it all in one go, because the roller can help shape a very nice fillet under the glass as it presses down, but if it is your first time you are wise to take the extra steps.

Depending on the epoxy you are using, you may be able to glass without sanding. Some brands will form a chemical bond if left overnight, especially if you form your fillets in the afternoon. It may be worth checking the literature. You still may need to do a quick scrape once it has gone off though, to get a smooth transition from the timber to the fillet edges. It's no big deal, but the fewer lumps and bumps the better it will look.

As with all these things, care taken with the preparation is the key to easy application and a quality look.


I just made my first S&G kayak after ten strip ones, and when I filleted the bulkheads (I didn't bother to tape them) I brushed with clear epoxy after I had finished all the fillets, i.e. when they were just starting to cure. They are then hard enough that the brush doesn't damage them, and the epoxy cures completely smooth and shiny, no need to sand, except very lightly to provide some "tooth" for adhesion in your case

John VanBuren

Fri, 10/05/2018 - 06:26


     An approach I have used with success is to use masking tape to define the edges of your fillets, carefully apply the thickened epoxy to the fillet, cover the area with clear plastic (I use gallon freezer bags that I have cut to size),  smooth out the plastic with a piece of stiff carding (an old credit card seems to work well, then when the epoxy is set enough to be no longer sticky pull off the plastic, and tape. If you catch it with the right timing it leave a nice smooth finish that just needs a wee bit of sanding on the edges, prior to applying the fiberglass and epoxy as a separate coat. 

   It sounds complicated but if you think it through it makes sense and does save a lot of sanding.


Keep Smiling,

John VB