Preliminary inquiry: Rescuing cracked/improperly finished old walnut item
Hello, sorry I can’t go into full detail right now, nor provide pictures, but I wonder if seasoned woodworkers can give me an idea about my predicament, whether solutions are likely (or not so hopeful) based on my impressions.
I obtained an attractive solid walnut wall clock (“regulator” style) built from a kit by an amateur about 3-4 decades ago. They did an excellent job, but I now see why they (or more likely an heir not wanting to be bothered with repair, is my guess) sold it online: The door, consisting of a walnut frame (3/4″ thick) holding a panel of beveled glass, is falling apart at the joints, and at one joint, a crack has continued past the joint to partially split one bar of the frame, along the grain.
Probably confirming a suspicion you may have: It appears to be an issue of defective finishing drying out the wood. I’m not a woodworker, but have built a couple of these kits in the past, so a very low-level amateur woodworker here with basic experience with wood finishing, many years back though. This clock was **lovingly** built by its owner, so lovingly that they kept all the original assembly/instructions with the clock, including them in the sale. I read them.
The instructions (which start by saying to read everything carefully before proceeding) warn the customer that the stained wood must be sealed on all surfaces, & that neglecting a surface (i.e., interior, unseen one) will result in gradual deterioration of the wood, drying, cracking etc.
This appears to have happened, as all surfaces on the clock, with the exception of the back of the (now falling apart) door have a slightly glossy polyurethane finish; it looks like they skipped the polyurethane on the door’s backside, which feels “dried out” to the touch, like it would be brittle if I would test its strength; the rest of the clock seems fine.
If this is the case, is any damage reversible or stoppable with oils, wax, polyurethane etc? I mean, can moisture be restored to the wood in some way that would at least partially restore its original strength? The front surfaces (and edges still look beautiful with their mild gloss.
If this is a case of irreversible, unstoppable damage, will it likely prove futile to try to screw in 4 “L” steel plates at the corners (obviously on the back of the door, unseen when closed), or something with thin dowels, or a combination? Or (gulp) contrive some kind of thin backing for the door, and glue it on? (The last seems very unlikely, but conceivable).
Or is this likely an unsalvageable situation, based on the description?
Thanks so very, very much for any responses at all!! It’s such a pretty clock, would be terrible shame if I can’t save it. And if it can’t be saved for the long haul (heirloom permanence), I’d like/hope to be able to get it patched up for a couple years, get some enjoyment out of it.
Thanks again!
Replies
This is a common finishing myth. All sides of every surface do not need to be finished the same, or even finished at all. For hundreds of years, only the show surfaces were ever finished. Undersides of tops, insides of cases and chests, etc, were never, ever finished. And if they were constructed properly, they did not warp or crack.
Adding finish to your click will not solve anything. What almost certainly hapoened is that the glass panel was fitted into too tight a space, and seasonal movement of the frame resulted in a crack. The only way to fix the crack is remove the glass, widen the rabbet a little, repair the frame, and reinstall the glass. The glass should be able to "float" a little in the frame.
Poor finishing can cause finish problems. Poor construction can cause wood problems. But finish wont affect construction.
As for dryness of the clock, unless it lives in a radically different climate than where it was made, the wood has almost the exact same moisture content than when it was made.
Thank you so much, John__C2!
That's very encouraging, such a relief! I hope I can be forgiven for my natural (or habituated) pessimism, particularly when I get good news that I want to trust, triggering a "too good to be true" response (protect myself from disappointment).
So obviously I want to trust that the "unfinished surface caused drying and cracking" theory is wrong. Is it the consensus that leaving one surface unfinished/unsealed is harmless?
I found this on another woodworking site:
"Finishing Wood
It’s a good idea to not only apply a finish to the outside of your project, but to the inside or underside as well. This will help the wood to absorb and release moisture more evenly.
Just imagine sealing one side of a board but not the other. The raw side of the board would absorb and release more quickly than the sealed side. The dissimilar rates of absorbing and releasing moisture could cause the board to crack over time."
That's exactly the stance you are saying is a "myth" (hopefully you're right). Is it possible the truth is somewhere in between, and leaving onside unsealed only increases vulnerability to moisture fluctuation issues, or that i conjunction with insufficient mobility for the class with too-thin rabbets?
Again, I'm so hoping you're right that I don't have to worry about the unsealed surface (and this causing uneven moisture absorption/release in the wood), but can I be confident there is no truth at all to this theory that some (apparently many) seem to treat as fact?
By the way, the kit was manufactured by Craft Products (St. Charles, IL, Elgin, IL. then some place in Wisconsin before it eventually folded, when the clock kit industry in general fell on hard times); I'm not a connoisseur, but my impression is that the company had great workmanship with beautiful designs, using exclusively oak, cherry, and walnut. (and very nice burls, such as the walnut burl on my clock). The designer-proprietor also, according to an obituary I looked up out of curiosity, apparently had written a few respected woodworking textbooks; he obviously held by the seal/-finish every surface the same theory.
Sorry for imposing, John__C2 and other folks; can't tell you how much I appreciate an and all feedback: so very much appreciated. Just trying to get my bearings on what kind of challenges will be involved if I attempt a repair or possibly pay for help; would be very, very nice to know I don't have to worry about finish and moisture issues, and just focus on expanding the rabbet a little (the glass already has/had some "play" btw, so that issue had been addressed already, albeit maybe not enough). Since the glass already had space to move around, should I be thinking maybe after so many years it was just the glue giving way? (The glass seems pretty heavy relative to the wood thickness - 3/4")... Again, thank you so much John__C2 and anybody else. But again: it's a consensus about unfinished surfaces?
I live in Canada (New Brunswick, in eastern Canada) where it gets COLD in the winter, and often hot in the summer. Often, unless the homeowner has taken steps to prevent this process, the air in the house gets very dry during the winter, and very moist during the summer. As a result, wooden furniture often simply fails after a few years. The reason, most commonly, is that individual pieces of wood, particularly wide ones, have not been finished equally on both sides, whether exposed or not.
Another person who wrote in response to this question noted that flooring, wainscotting, etc., do not cup. There are two factors here. First, the back side of the wood in question is usually flat against a solid surface, thus limiting moisture exchange on that side of the wood. The second is that most such pieces of wood are narrow, and cupping mat occur but wouldn't be particularly noticeable. A good straightedge will usually show slight cupping, especially in the winter months when the air is usually drier.
I've designed and built several hundred pieces of furniture -- many different styles, many different woods -- and have always followed Bruce Hoadley's wise advice: whatever you do to one side of a piece of wood, do to the other. (See Hoadley's book, "Understanding Wood" for a detailed explanation.) The "back" side needn't be finished to the same level of excellence (eg it need not be rubbed out with rottenstone), but it does need to be given the same level of moisture protection as the show side. The one time I failed to follow Hoadley's advice was on a freestanding butcher block, 3 feet square and 15 inches thick. It went to live in a house with typically poor overall climate control. After a couple of years, it split badly. Once was enough to convince me of Hoadley's wisdom.
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