Hi all A while back on the list I said that I was going to try burnt rice hulls in epoxy as a filleting material instead of good old bondo. I don't like polyesters and bondo is polyester. My first try was with unground burnt rice hulls. Burnt rice hulls is a form of amorphous carbon and active silica fiber. Burnt rice hulls can be added to things like concrete block to drastically increase the tensile and crush strength. Burnt rice hulls unground are fine silica fibers that are active and very strong. Active meaning they have active silica sites for bonding or increasing the thickness of polar fluids. I mixed burnt rice hulls with a table top epoxy from Raka inc. The tabletop epoxy is very thick, fairly cheap and is a one for one hardener to resin ratio so it makes it easy to mix the two together after thickening with burnt rice hulls. I just kept adding burnt rice hulls until the mix was very thick. The consistency and look was EXACTLY like fibered roof tar. Just as sticky and just as messy only harder to clean off of things. The mixture hardened fine and made good fillets between the hull and the pilothouse. Sanding was straight forward and easy. The resulting composite is tough as nails and hard. I have to tell you, I did not expect it to set only because it looked and acted just like tar. Somehow deep down in side I thought if it looks like tar its gonna act like tar and remain sticky. It did harden after two days at 50 deg. I next wanted to make something to fair the sides of the pilothouse and reduce the amount of sanding that I have been doing. The results of experimenting have been beyond my wildest dreams. Again I used the tabletop resin from Raka inc. In 200 cc's of resin I mixed 15grams of Cabosil fume silica and added milled platelet mica until I had a peanut butter like paste. In 200 cc's of hardener I mixed 15 grams of Cabosil fume silica, 30 grams of high silica milled burnt rice hulls and thickened to a peanut butter like consistency with milled platelet mica. The resin mixture was a tan color and the hardener mixture was jet black. Fume silica increases thicktroscopy or in english, anti-sag properties. Mica is gold when I comes to self leveling, spreadability and sandability. Anything that you add mica to will be silky smooth, mica tends to decrease adhesion some but not a lot in comparison to its ability to reduce work. Burnt rice hulls increase toughness, impart thicktroscopy and color. Mixing was straight forward 50% tan resin mixture and 50% black hardener and mix by kneading on a board. The mixed compound is jet black. I used a 10" tape knife to apply this fairing compound to the sides of the rough pilothouse. This stuff applied like the best drywall mud that I have ever used at 50 deg. No sag and enough self leveling to make a gloss surface without a ripple in it. The fairing compound is not yet hard enough to sand after a day but I doubt that I will need to sand it very much anyway. Maybe with 220 grit paper. That stuff is great. Needless to say I am very pleased at this point with both the fillet compound and the fairing compound. <grin>.