I am a furniture maker and have shunned doing any repair work and now I know why. A very close friend has asked me to repair the straight chairs to his dinning set. He said he is reluctant to have anyone else do the repair since I have already done some surface finishing repairs. The backs and the legs of the chairs are a single piece; they rock slightly where they join the seat frame. The seat frames have large grooved glue blocks at each corner and they are solid and stable. I have not been able to determine how the back and legs connect through the seat frames. This is a very high quality Italian Provincial dinning set with four straight chairs and two side chairs with arms. It was made in Italy and shipped here at least ten years ago. The rocking is not a new problem. The two armchairs do not rock.
At first glance the obvious solution would be to put a lag bolt through each rear corner block at the back of each seat and into the backs where they run through the seat and pull them in to stabilize them. But without knowing how the backs connect through the seat I am a bit reticent to do that. I have talked to two cabinetmakers and got two different responses so far. One agreed with the bolt the other said that the chairs could have been made to rock slightly to avoid undue stress at the joint.
Anybody have a solution, or should they rock?
Replies
Rocking reduces stress on the joint? Was this guy just pulling your chain?
Do you have a friend who is a dentist. You might be able to get him to Xray a joint to see how it is constructed.
If these are truly high quality chairs they should be M & T joints, and the rocking would indicate the joints are loose. Adding metal is NOT a good solution in general, but separating the joints, cleaning out the old glue (unless it is hide glue) and adding a veneer shim to tighten it up is a pretty challenging task, especially if you don't want to end up refinishing the chairs due to the process of separating the joint.
There is another possibility: The chairs were meant to rock and since the arm chairs don't, then they are defective. The solution is to give them a good whack with a 2x4 to loosen them up a bit. (Pad the 2x4 to avoid damaging the finish.)
All of that is in jest of course. The chairs have loose joints. Take them apart to fix them.
Twin,
Your chairs have dowels at the back leg joint. No factory chair maker uses mortise and tenon joints, haven't for 50 yrs or more. Sure you can find some hand made high end chairs with M&T joints but not from a factory.
Do your chairs have stretchers? I'm guessing,not. With a joint surface of only a couple of sq inches and 2 dowels with hardly any glue on them, that is why the chairs rock. The corner blocks are the only thing holding the chairs together. I've repaired quite a few of these, sometimes with sucess, and other times not.
To repair the chairs the corner blocks have to come out. You can come from the inside of the chair and see if the back to side joint will open any, if it does any at all, the chair can be repaired. It takes a bit of finess to remove the corner blocks, an 1/8" chisel helps, for the grooved recesses. OH yeah, and big hammer( last resort).
Hopefully you can successfully repair their chairs.
I just couldn't believe that the M & T joint was not used in furniture anymore. And I think I am right. Dowels are such poor substitutes that I can't imagine people paying more than a grand for a chair will accept them. (Or rather that the cost of damaged chairs to the company's rep. wouldn't lead some to use M & T joints.
It took only a few minutes with google to find factory chairs that were said to use mortise and tenon joinery. And they weren't all supper high end companies. Now this wasn't a definative survey, and where exactly the joints were used wasn't said.
In fact one company sold children's chairs for well under $100 each that were constructed with mortise and tenon joints. Target market schools and day care centers.
Could be some use them, but most Major factories do not. I've repaired furniture since '73. Have never repaired a factory chair with tenons. I refer to a factory as having an assembly line, not bench builders like Thos. Moser. The only way to tell what is in the joint is open it up. Dowels are tenons, just round. And in some cases I would say they can be stronger, than a classic M&T joint.I wouldn't get hung up on the cost factor, most designers and buyers purchase because of the look and design, not the construction techniques utilized.Furniture...the Art of a FurnitureMaker
You don't think Moser has a factory?
Of course,you don't get much call to repair the joints on M & T joined chairs. And there is no way one can, correctly argue that dowels are stronger than M & T joints, each being properly manufactured.
Of course there are doweled chairs, plenty of them, but I can't see why in this age of single and double end tenoners, and CNC machines that the stronger technology would cost more than a drill and dowel technology, especially given the potential for reducing warrantly costs.
Edited 11/5/2005 4:46 pm ET by SteveSchoene
Steve,
OF course Moser has a factory, but it's not an assembly line. If you ever get to go in a modern furniture factory of size, you will see it operates like a car manufacturing plant, the line moves constantly.I probably shouldn't have have lumped all manufacturers together when I said they don't use M&T in chairs anymore. But you have to read very closely the description. Found a manuf. that uses M&T in their chairs, but when you get to the detail of each piece said they used solid round teak Tenons in their teak chairs. Sounds like a dowel to me.Someone once told Sam Maloof he didn't make Fine Furniture because he used Screws in his chair joints. He uses dowels also. Something to think about.I'm saying M&T joints are useful and strong joints, just in some situations they are not the best joint. Google up Dowelmax they have an interesting test on their site.I rarely use dowels for joints. Probably 95-99% of my tables or other frame type pieces are a M&T joint. I didn't buy a mortiser to let it sit there.I hope Twinn will respond and let us know of his success. Furniture...the Art of a FurnitureMaker
Twin,
Whether the chairs have dowel or M & T joints is not really important. They must be disassembled and reglued/repaired. All joints-seat/leg, stretchers, etc.
Metal screws or lags are not an option.
The rocking is a sign of loose joints, not a factory design!
The glue blocks can be chiseled off, reinstalled or even replaced. Gently and patiently tap the joints apart with a rubber lead filled "dead blow" mallet. If dowels were used, I would definetly replace them because they are weakened by the rocking/disassembly. When reassembling, use good quality band straps (around the seat/leg joints and around the stretchers if there any) and put a good amount of weight on the seat (put a board across, then concrete blocks or something similar). This weight will help keep the chair level while drying.
I would use epoxy glue, because it will fill the gaps and create a solid joint.
This is one of those projects where there are no shortcuts, but if done properly the end result will be worth the effort.
PCM
Good day all! ;-)
one more little thing to think about,On the disassembly, of the chair is what kind of glue was used to hold the chair together. Before using force to break down the joint, try this?Vinegar. using vinegar can break down most glues used in wood working today, (I said,most not all!) try a little on/in the glue joint and see if it losses up,or becomes gummy, if so then all you need to do is add the vinegar to the gaps and wobble the joint a little to break the glue joint,then disassemble it.It shouldn't take longer then a few min. to see if the vinegar will work for you.
a needle and sarange dose a nice job of getting into the joint, woodworking stores sell small glue bottles with a needle/tube ,that get into most joint nicely.Ive even used a eye dropper to get the vinegar into place. a little gos a long way, you dont need a lot to break down a joint.
rebuilding the joint can be done by using wood shaving from a hand plain,or veneer. sometimes just replacing the dowel can fix the problem.
Good luck on you project,Let us know how it goes!
C.A.G.
Curtis,
I have used vinegar with good results. Definetly an option.
I hyope twin reads this
PCM
PCM,
excellent advice, but there's always a reason the joint is loose. Sometimes it is because of poor design. Sometimes manufacturing defect, no glue or just a small drop used.The other two factors that affect the stability and sturdiness of a chair are Age and Abuse.I agree the type of joint doesn't matter, it still needs to be fixed. Chairs take a lot of time 4 hrs would be fast to do it right. So it can get costly.Curtis- the Vinegar, forgot about that. A good piece of info for anyone taking a piece apart.Furniture...the Art of a FurnitureMaker
NO NO NO Epoxy! Gap filling glue is a myth. And it will be almost impossible to dissolve in 20 years for a refastening. If you really need it, first shellac the joint and then let dry. Then use the epoxy. In 20 years, alcohol will dilute the shellac and the joint can be "broken.
Good repair can always be done with.... Elmers White glue. If really necessary, add some wood dust to it...
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