Tuesday, August 10, 2010

Rocking Chair Repair


Here's another old furniture repair post, and also a lesson on the importance of grain direction.

This old rocker had a broken runner:


A closer look revealed how the sawn runner split down the grain. If the runners had been bent, with continuous grain, this couldn't have happened.


I didn't need to disassemble the chair; it was easy enough to loosen the screws and rotate the broken parts to get at the surfaces needing glue. The brown fuzzy strip is adhesive backed felt to protect the bamboo floor.


Here's the clamp swarm holding things put after glueing:


The glue probably would have been enough, but just to be sure I removed some of the felt and drove two finish screws across the joint. To insure that the screws pulled everything tight, I bored two different size pilot holes. First I drilled a small pilot hole (the size of the screw's shank) the full depth of the screw, and then bored a larger hole (the size of the threads) just as deep as the break. This way, the clamping effect was between the threads of the lower part and the head of the screw.


To replace the felt, I squished the new felt with clamps until it was the same thickness as the older felt. Although I am confident this repair will hold, I didn't want to tempt fate by putting a lump right under it. Confident is confident, but safer is better.

Oh, and although I already pointed out that bent runners would not have failed this way, I also concede the point that these sawn runners lasted almost 100 years. So there you go...


11 comments:

  1. Hello Dan:

    Ya que te rompiò la mecedora ( rocking chair), y ya puestos al trabajo y además te lo pasarías bien, por que no le haces unos balancines nuevos, construidos con láminas, y después los imitas a antiguo ( ageing ), por que viendo el sentido de la fibra de la madera en los balancines creo que si fuerzas un poco al balancear, te romperá otra vez. ¡ ojalá me equivoque !, je, je,je.

    Un fuerte abrazo from the north of spain
    Nice and very instructive blog.

    Anxo mosquera

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  2. Anxo - Well I hope it doesn't break again! With the good glue surface and reinforcing screws I don't think that spot will break again, but of course I could be wrong. Also, another spot might break. We'll see. If either happens, then I will consider making an entirely new runner with laminations or steam bending.

    My general repair philosophy, especially with antiques or sentimental pieces, is to do the least "invasive" repair first, saving the more intense repair techniques (whole part replacement) for back-up. Of course, I have the luxury of having this chair in my living room. If I was dealing with a client, I might be tempted to go the whole runner replacement route first.

    Thanks for commenting!

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  3. Great work! I think the glue and screws should keep it from breaking, 100 years strong!

    www.Stratton-Woodworking.com

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  4. Mark - Thanks - I hope it lasts another 100 years, that would be great! Nice looking furniture, and I'm envious that you live in Vermont!

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  5. Hey Dan, I have a question having nothing to do with this post...hope that's ok. I came across your scary sharp post last night and you sold me on the method big time. Where did you buy your glass and paper?

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  6. Bud - The glass came from my brother, but I think he got it at a local glass shop. I don't think you need to worry about it too much, if it is thick enough and well supported on a flat, stable surface it should work fine. I've also heard of others using granite tiles from home centers. I haven't tried this but if they were truly flat it should work.

    The paper is mostly from a hardware store, but the finer grits are from NAPA. You might have to ask them for it; at my local store they are in the back. I think they stock up to 2000.

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  7. Thanks for the great tips. you learn something new everyday. Randy!!

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  8. Randy - You're welcome - I'm glad it proved useful. And so far so good - it's holding up fine.

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  9. Since this post is older, not sure you are going to see this. I just got an old rocking chair and the runner is cracked but not fully broken, so I can't really get any glue in there. Also, it is more of an up and down crack - not the angled break of your chair. Thoughts?

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    1. Did it break across the grain? If so, you now have end grain exposed which makes fixing it with glue rather unlikely (unless it is a jagged break with interlocking "fingers" of wood grain). If it broke with the grain it is easy to fix with glue, although if the grain ran across the runner it would be an unusual construction choice as "short grain" is notoriously weak. Either way, to most effectively glue it, you might have to finish breaking it first.

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  10. Hi Dan
    I bought an old mission style oak rocker. It doesn't rock smoothly, seems to "catch" a bit at midway rocking point. I see no obvious warping or breaks in runners. Is there anything I can try? Thanks

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