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Discussion Starter #1 (Edited)
Hello,

I have a very old rocking chair that has been passed down to me (I was raised in this thing) and now my first born will be raised in it! I'm fine with sanding and finishing it, but the part I'm not sure on is the best way to deal with cracking in the base. It has been starting to split down the length of the seat bottom. Previously someone had done some "repairs" by putting a supporting strip behind it.

I'm wondering the best way to close out and secure these cracks. I was thinking of trying to spread them open as much as possible and inject wood glue down inside as best as possible, then clamp, sand, stain it. I'm hoping I can remove the strips on the back that were previously done. I suppose some support on the bottom of the seat could also help hold it together?

Thoughts?

(if this is in the wrong place please move, it would be nice to have a restoration section which I didn't see)
 

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I can see only one picture of the back. From that picture, the chair looks to be in generally good condition. Considering it's history, I would advise a very conservative approach; perhaps just a good cleaning and a good coat of quality paste wax periodically. At most, I think I would buff it lightly with 0000 steel wool or equivalent abrasive pad and apply a couple of spray coats of shellac. Without the pictures, I can't comment on the cracks.


OK. Now I see them. Do they look any worse from the bottom? From the pictures i see, the cracks do not look too severe. They look like shrinkage cracks. Has the chair been stored somewhere like a hot attic? Anyway, it doesn't look like total failure is eminent. I would clean and finish as above and keep a watch on the cracks. If the chair is kept in a climate controlled environment like your home, I doubt it will get worse.


If you think the cracks are or will get worse, you can use something like a biscuit joiner to cut perpendicular slots across each crack in the bottom surface and cut a wood spline to fit the slot snugly. Glue the spline in place and cut it flush with the bottom surface. I wouldn't try filling the cracks, but by putting glue into the slots and pressing the splines in, this will push glue into the crack and help with the reinforcement. I would use epoxy or plastic resin for this.
 

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The cracks are due to the wood shrinking over the years. Perhaps the wood was a little green when built. To fix the cracks isn't an easy job. You would have to dismantle the rocker and remove the seat. Then cut out the cracked wood and add new wood in it's place. If you do this be sure to re-assemble the rocker with two part epoxy. Wood glue doesn't work on previoiusly glued parts.

The strip of wood across the back is only going to cause more cracks.could prevent the wood from shrinking more and crack to relieve the pressure. If you are going to re-enforce what is there I would screw a couple of pieces to the underside of the seat. You would have to elongate the screw holes to allow for the wood to expand and contract and use pan head screws with washers. The idea is to just brace the seat for safety reason so the seat doesn't break in two while someone is sitting in it. From what I can see I don't believe that would happen. You might just putty the cracks.


As far as refinishing the wood should be chemically stripped before any sanding is done and that is also difficult now. Big brother has banned the chemical that makes paint strippers work. Only the professional refinisher is allow to buy that now. You might see if you can find a professional refinisher and have them at least strip the rocker for you. It would be a lot less headache if it were completely clean of the old finish.
 

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That is a beautiful chair with a very nice patina reflecting many years of use. Before you do anything to it, you should do some research to see if it has any antique value. If it does, anything you do could affect it's value; including refinishing.
 

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where's my table saw?
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Leave it be .....

Anything you attempt to do without a complete tear down, sanding and reassembly will not permanently solve the cracking in the seat bottom. JMO. The cracks just add "character" and will not affect the strength of the bottom. I would also remove the "support" strip as it will do nothing to strengthen the bottom and it looks terrible!

FYI, new wood glue will NOT adhere to old glue. There is a chance it was initially glued with hide glue, if it's quite old? Hide glue can be removed with steam and hot water, but I don't advise doing that either.

I did a complete teardown, reglue, reassembly and refinishing of these Murphy chairs circa 1910:
https://www.woodworkingtalk.com/f9/what-chairs-these-39917/

 

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It would be best to dismantle, crack the seat apart, clean up the glue residue, and re-glue.

But, before you go to that extreme, see if it the split will close with clamps. If it closes, you’ve got nothing to lose, work some unthickened epoxy or wood glue into the crack top and bottom & and clamp for 24 hrs. Don’t use 5 minute epoxy it is too thick. I’ve heard you can apply suction from a shop vac to the other side of the crack to pull glue in.

Or, just leave it alone and route in some butterflies in the bottom (my preferred option).
 

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mike44
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Looks like a nice chair that probably does not need fixing. You could try removing the strips under the chair and clamp the joint tight. If clamping pulls the seams tight then epoxy without filler can be used. Masking tape on either side of the seam and under the seam before filling with epoxy. Clamp up and remove excess epoxy as you clamp. Remove the clamps and tape after 24 hrs. Epoxy and hardener flows like water if you get the stuff used in boats.
mike
 

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So far, it doesnt look all that bad. Would be able to tell more if the strap in the back is removed. It has to come off anyway so might as well do it now. I am in the school of NEVER use wax. It will probably reek havoc with most finishes. In professional stripping chemicals are not guaranteed to remove wax.
Sometimes it is better if the whole seat would just split apart, then you can do a proper repair. but that dont look like it is going to happen any time soon
I would just sand it as much as needed, save the dust and fill the cracks with a super glue (cianoaccrylate) and sawdust mixture.
Squirt some CA glue (the thin stuff) into the cracks - then use your finger and and press some sawdust into the crack. Then squirt some more CA glue on top of that and then add more saw dust again followed by anothe squirt of CA glue. You can build layers of the crack filler process as much as needed. Like someone stated, the chair dont look like it will come apart on its own.
 

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The Nut in the Cellar
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If the crack is wide enough, there is an old trick for working glue into cracks using dental floss to push a slow setting glue as deep into the space as possible and then clamping until cured. I refinished an heirloom family Boston rocker many years ago that had been finished over several times restoring it to its original color. Due to its age and the stripping process, nearly every tenon was loose in its hole. After coloring the chair with dye, I used a fine artist's brush to bleed a 50/50 mix of polyurethane varnish and thinner into each join until they would not accept any more. This required situating the chair so that each join was facing up so the varnish would not run out until cured. This took quite a few days, but I eventually got each and every join solidified. I then finished the top coats of the new finish. That project was done about 25 years ago and the chair is still tight with no loose joins anywhere.
 

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Discussion Starter #11 (Edited)
Lots of great ideas here, thanks everyone! I can confirm that the chair is not at immediate risk of falling apart, it's safe to sit on, but we want to make sure it doesn't continue and also just make it look a bit nicer, it is very beat up with other holes, scratches, dent's/dings, etc. So part of this is about making it "nice" again, don't really care about resale value, etc. Just want it to last for many more generations and it's not looking like it will at this point.

I haven't thrown a clamp on it to see if I can close up the gaps, if I can I kind of like the epoxy route. There are various holes and other damage that I'd like to fill/repair, and there's some discoloration (green, any ideas what this is?), so that's why I was thinking I need to do a light sanding/restaining.

I also considered the "break it apart, reglue" approach, but will test just clamping it first. I can see the argument and allure to the patina, but it's a little rougher shape then the pictures show....was thinking if I clean it up restain, it's going to make it last longer then my daughter....
 

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we have a forth generation rocking chair - pix of parents-kids-their kids - their kids kids.... to go with.... so I sure do appreciate the problem.


"disassembly" well , , , , that may not be as easily done as typed.
the pix seem to show cracking at the joint. those are best re-done with epoxy.
the alternative is disassembly, cutting off the glued bits to depth, inserting spacer to suit . . . no simple task.
spread the joint as wide as possible, push/squeeze epoxy into crack to max 100% coverage as possible. clamp.


it's a bit of a crap shoot - it'll work, or it'll make a bigger mess.....


if you don't perceive a structural issue, don't do a thing.
 

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The Nut in the Cellar
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The green smear on the seat looks like it might be paint that was wiped off while it was still wet and not completely removed. If it doesn't come off with soap or mineral spirits, I'd be temped to leave it as a "character" mark. The rocker I redid had the factory finish (walnut color) stripped and re-stained mahogany and varnished by my Father-In-Law. Then, twenty years later, in the '70s, he antiqued with an avocado green base coat and tan glaze. This was the condition I started with including a broken rocker and a broken back spindle. After stripping, bleaching, and sanding the chair, I discovered a small hole in one of the back uprights filled with avocado green paint. Even after dyeing the chair with a walnut colored dye, the green dot remained, so I left it as a small token to Dad.
 

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With respect to those who recommend it, you will not be able to clamp those cracks together. They are only a short segment of relatively long wide pieces that have shrunk on the ends. To put that much pressure on the wood would crush it in order to squeeze it together and you likely will never get them closed. And, if you did, the spring back forces would be so great the closure would probably not last.

If you must repair the cracks, forget the clamps and fill them with epoxy. To do this, drill a hole (about 1/4" will do) into the center of the crack from the bottom. Drill the hole about 3/4 of the way through the bottom. Then get a dowel the same size and sand it down so that it is a slip fit. Fill the hole with System 3 or similar epoxy and then press or tap the dowel in. The dowel will act as a piston and force the epoxy into the crack. If needed, remove the dowel and do it again. Taping the crack on the top and bottom surfaces will help direct the flow, help with filling and help prevent waste. When the crack is filled, leave the dowel in place and cut it off flush with the bottom. Then sand everything smooth, strip the old finish if necessary and re-finish as you like.
 

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With respect to those who recommend it, you will not be able to clamp those cracks together. They are only a short segment of relatively long wide pieces that have shrunk on the ends. To put that much pressure on the wood would crush it in order to squeeze it together and you likely will never get them closed. And, if you did, the spring back forces would be so great the closure would probably not last.
Very good point, but you never know till you try. But I agree if it takes a huge amount of pressure to close, its an issue.

If you must repair the cracks, forget the clamps and fill them with epoxy. To do this, drill a hole (about 1/4" will do) into the center of the crack from the bottom. Drill the hole about 3/4 of the way through the bottom. Then get a dowel the same size and sand it down so that it is a slip fit. Fill the hole with System 3 or similar epoxy and then press or tap the dowel in. The dowel will act as a piston and force the epoxy into the crack. If needed, remove the dowel and do it again. Taping the crack on the top and bottom surfaces will help direct the flow, help with filling and help prevent waste. When the crack is filled, leave the dowel in place and cut it off flush with the bottom. Then sand everything smooth, strip the old finish if necessary and re-finish as you like.
I really like this idea!
 

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where's my table saw?
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some additional suggestions .........

Lots of great ideas here, thanks everyone! I can confirm that the chair is not at immediate risk of falling apart, it's safe to sit on, but we want to make sure it doesn't continue and also just make it look a bit nicer, it is very beat up with other holes, scratches, dent's/dings, etc. So part of this is about making it "nice" again, don't really care about resale value, etc. Just want it to last for many more generations and it's not looking like it will at this point.

I haven't thrown a clamp on it to see if I can close up the gaps, if I can I kind of like the epoxy route. There are various holes and other damage that I'd like to fill/repair, and there's some discoloration (green, any ideas what this is?), so that's why I was thinking I need to do a light sanding/restaining.

I also considered the "break it apart, reglue" approach, but will test just clamping it first. I can see the argument and allure to the patina, but it's a little rougher shape then the pictures show....was thinking if I clean it up restain, it's going to make it last longer then my daughter....

Try a pipe clamp first to see how easily the gap closes. But first use a shop vac to suck out any particles that would keep it from closing up. Even run some dental floss along the gap if you can and see what comes out. Then apply your clamp gently.


With respect to those who recommend it, you will not be able to clamp those cracks together. They are only a short segment of relatively long wide pieces that have shrunk on the ends. To put that much pressure on the wood would crush it in order to squeeze it together and you likely will never get them closed. And, if you did, the spring back forces would be so great the closure would probably not last.

If you must repair the cracks, forget the clamps and fill them with epoxy. To do this, drill a hole (about 1/4" will do) into the center of the crack from the bottom. Drill the hole about 3/4 of the way through the bottom. Then get a dowel the same size and sand it down so that it is a slip fit. Fill the hole with System 3 or similar epoxy and then press or tap the dowel in. The dowel will act as a piston and force the epoxy into the crack. If needed, remove the dowel and do it again. Taping the crack on the top and bottom surfaces will help direct the flow, help with filling and help prevent waste. When the crack is filled, leave the dowel in place and cut it off flush with the bottom. Then sand everything smooth, strip the old finish if necessary and re-finish as you like.

The best way to stop a crack from spreading is to drill a small hole just beyond the it's termination. Then put the epoxy into the hole and suck it down from below with a shop vac. Then I would insert a a bamboo "dowel" into the epoxy filled hole, leaving it long enough to cut off and sand flush. Clamp it up and it will never show. I would use a bamboo skewer which about 1/16" in diameter and some good wood. Tooth picks are typically tapered so, but if you can find one that isn't that would work also.
 

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The best way to stop a crack from spreading is to drill a small hole just beyond the it's termination.
I don't mean this to be argumentative. Please consider it a question. I know this works for solid materials like metal and plastic. I question whether it works for something like wood that has a grain structure. I think a crack forming due to shrinkage is going to follow the grain regardless of the presents of a hole in it's path. I've done a little searching around and have not come up with a definitive answer.
 
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