Q: I finished an exterior door two weeks ago, and it has already started to fade from the sun. What should I have done to prevent this from happening?
Kevin Hancock: Some coatings are more light resistant than others. Spar varnish, for instance, has resins that resist fading from the sun. Additionally, selecting a finish with UV blockers will protect not only the coating, but the colorants on the wood under the finish. When choosing a stain, be sure to use a pigmented stain for better sun resistance.
Greg Williams: Use a good quality pigmented stain for color and coat with a varnish containing ultraviolet inhibitors.
John Brock: Some clear finishes contain UV blockers that will help slow the fading, but nothing will stop the power of the sun over time. One approach is to use a grain filler tinted with a pigment. The UV light will still lighten the wood, but the pigment will be less affected and maintain the clarity of the grain. As it fades, a coat of finish tinted as a toner can be used to restore some of the color, but that, too, will fade. My front door faces south. It's painted.
Q. I am about to make several raised panel doors. They will be painted. What precautions can I take to prevent the finish from cracking between the panel and the frame due to expansion and contraction?
A. Michael Dresdner: "The best one is to pre-finish. That means paint the panel BEFORE you put it in the frame. That way, even if the panel moves, it will never show a raw wood line. And since the finish will not be "bridged" over the joint where panel meets frame, there will be nothing to crack."
A. Ellis Walentine: "It's fairly standard procedure to finish the panel before you assemble the door. This way, any contraction will expose finished wood. If you plan to apply a heavy film finish, such as polyurethane or regular varnish, you might not want to do this, because it will add too much thickness to those edges and they won't fit your grooves on assembly. In this case, just wipe a coat of your finish on the edges of the panel to seal and saturate the wood's color before assembly."
A. Lee Grindinger: "Use MDF for the panel and glue it in place when you assemble the door. A solid wood panel will not work here because you can't glue a solid panel in place. A composite like particle board, plywood, or MDF can be glued in place without tearing the door apart when the humidity changes. MDF is quite paintable so it's your best choice for these doors."
Q. The older house we've just bought has a nice wood panel door leading from the hall into the garage. Unfortunately, the mortise-tenon joint nearest the lockset has opened a gap of about 1/8 inch between the rail and the style. (I hope I have the terminology correct!) In addition to looking bad, this makes the door had to close.
I have considered:
1) trying to inject glue into the joint and clamping it back into alignment
2) taking the door apart and regluing.
A. Rob Johnstone: "Take the door off its hinges and put some clamps on it at the point of the gap. Test to see if you can snug the joint back up before you put any glue in the joint. If you can tighten things up with your clamp, open the joint back up, work some glue into the opening and clamp that baby tight. Allow the glue to cure for 24 hours and then rehang it. This will likely take care of things, but if there is some structural problem you can't see, the problem may reoccur. "
A. Michael Dresdner: "Those are two very different options. The first one would be much easier, but the second one will actually work. The odds of such a joint holding after glue was injected into the gap are dismally low. However, if you take the door apart, you can clean the joint, refit it if necessary, and glue it up properly, after which it will hold.
Look for moving, bowing, or twisting wood on the stile when you take it apart, as this is the most probable cause for the gap in the first place. Machine the mating surfaces if you must, but make sure the joint goes together with no more than gentle pressure. If you have to force the parts to mate with clamps, it will eventually come apart again."
Q. Oak veneer door: this woodworker wants to put an oak veneer over his solid maple front door for some very good reasons. What would be the best way to do this considering temperature variations, movement, etc.?
A: Michael Dresdner: "The best way would be to make a new door out of something more stable than maple (mahogany, teak, and VG red cedar would be my first choices). Adding veneers to old solid maple doors is asking for trouble.
If you must do it, veneer both sides of the door the same way, and use a crossband under the oak veneer. A crossband is another veneer that goes in the opposite direction from the top veneer and the core. Typically, poplar, lauan, or corupixu is used for the crossband. Use rigid exterior construction adhesives (urea formaldehyde type) for all the veneers, not contact cement or interior wood glues.
But, as I said before, I'd make a new door."