PL Fi:x:Two-part filler for repairing wood

I've always liked the idea of mixing two things together to get something entirely different. Think plaster and water, thinset and latex, or vinegar and baking soda (essential in fourth-grade volcanoes).  With adhesive fillers like epoxy and polyester fillers (Bondo or High-Performance Wood filler), mixing two parts together has several advantages. Keeping each part separate until you need it helps them stay fresh longer. There are no solvents to evaporate, so there's no shrinkage. And when the two parts come together, the resulting chemical reaction produces a product that's unaffected by water or the weather.

Now, with Henkel's new PL Fi:x, there's a third type of two-part filler based on polyurethane resins, which have some definite advantages over epoxy and Bondo. Measuring out the two components is dead easy: Squeeze out two equal-size strips of the white toothpaste-like goo, and one equal-length strip of the brown goo; mix them together until the color is uniform, then apply the mayonnaisey mix to any wood you have to fill. It's a bit more demanding than Bondo, but much less fussy than epoxy.

Setting time is about 15 minutes. Fi:x doesn't heat up as it sets. (Runaway, hot reactions can cook polyester into crumbs, or drastically shorten the working time for epoxy.) The reaction between the two compoents is smooth, cool, and steady, and there's enough open time to tool it smooth when it reaches the consistency of Jif peanut butter. After it's fully hardened, in 4 hours, you can drill, cut, rout, sand, and paint the tan filler as easily any softwood. (Epoxy and polyester aren't so tool friendly.)  Fi:x also sticks to wet and oily woods, metal, stone, and certain plastics.

A couple of caveats: You have to paint it (UV rays eat up polyurethanes). And its shelf life is limited: one-year if not opened; six months at most after opening. Given how easy it is to use, and all the places around my house that need a good, easy-to-use wood filler, there's little chance of my Fi:x going to waste.