Q: What is a waterbased pore filler and who makes it?
Richard Jones: Many companies offer ready-to-use waterbased filler, and you are bound to find it at your favorite woodworking specialty store. Don't forget the centuries-old method of using plaster of Paris mixed with powder pigments or waterbased powdered paint. I've been using this technique all my working life.
Michael Dresdner: Another handy format for waterbased pore filler is the multipurpose waterbased putty and filler that starts out thick enough to use as putty but can be reduced with water to work as a pore filler. Here's a
link to one such product.
Q: I've always made up my own wood filler with dust from a sander, glue and water. At one point, I had some filler that I had mixed up turn black. Do you have any idea what type of dust contaminated my filler? I can't seem to pinpoint the type of wood that was being used that might have caused it.
Michael Dresdner: It's not the wood alone, but the combination of wood and glue. Waterbased emulsion glues, like white and yellow glue, often contain a strong amine to keep them in suspension. The amine can react with any wood high in tannin and turn it dark, just as oak will turn dark if you wipe it with ammonia. I always advise using hide glue for wood filler. It will not react with any wood, is pH neutral, sands better, is reversible, does not creep, and will take water-soluble dye stains.
Q: I've been looking for pore filler, but all I can find is wood putty ... including at Home Depot. Can I make some myself? If so, what do I use? I would like to try different colors as well for special effects.
A. Michael Dresdner: "Yes, you can make it yourself, from putty, or you can buy it, if you know where to look.
"Pore filler is modified, thinned putty, and the truth is, you could thin wood putty with its reducer and use it as pore filler. In fact, one company, Rockler, makes a putty called Wunderfil that has instructions on the container telling you how to thin it to make pore filler.
"As you've noticed, home improvement stores, like Lowe's and Home Depot, do not carry pore filler. However, virtually every woodworking specialty store, mail order catalog, and online store does. That includes Rockler , and Mohawk to name just two.
"You can custom color any pore filler (or putty) using universal tinting colors (UTC's), or choose artist's colors in the correct medium for the putty or filler. Use artist's acrylic colors for waterbased putty/filler, and oil colors for oil or solvent based putty/filler.
Q. One woodworker heard you could repair projects by saving some of the sawdust and filling the mistakes with a mixture of the sawdust and an adhesive. What kind of glue should he use to mix with the sawdust?
A. Rob Johnstone: "This may work in certain situations ? for example, with extremely dark woods like ebony. But in general, I consider it a less than optimal technique, particularly if you are thinking of staining the project after the repair. Wood fiber mixed with adhesive and used as filler like this will not accept stain. It is in essence "sealed" by the adhesive."
A. Michael Dresdner: "Hide glue works the best. Titebond or white glue will work with some woods, but with others it turns the dust dark."
A. Rick White: "It depends on how big a mistake you're trying to fill, but any mixture of glue and sawdust will resist stain. Every glue I can think of will seal the filler against stain, so you'll get very uneven results. Even those paste wood fillers you can buy don't match the wood or stain exactly. So if you're repairing small mistakes, these filled areas might not be such a big deal. But if you're trying to fix a big ding, this sawdust and glue mixture will be very noticeable in the final finish."