Expert: Greg Scholl - 6/27/2011

Question
QUESTION: Hi Greg,
I have a shaker rocker chair that needs to be stabilized because the dryness has loosened the joints.
But only some of the joints have broken...the others are still solid.
How do 8I proceed?
How can I tell which glue has been used and how do I loosen that glue.
If I re-glue a joint with wood glue, will the glue that has already penetrated the wood interfere with new glue adhesion?
It's an original 1930's shaker piece (I'm told)

ANSWER: Hi Lorne, are the joints broken or just separated? If the joints have actually broken, then it's a much more difficult and skilled repair. If the joints have just separated, then likely the other joints can be persuaded apart with a dead blow mallet or a hammer and block of wood....likely it was originally glued with hide glue which is water soluble, and gets brittle with age (you can test it by rubbing wet fingers around the glue...it will get sticky almost immediately if it's hide glue).If there are signs of modern glue, then it can be tougher to disassemble...but that's the best course of action...disassemble the whole chair and reglue with the appropriate Glue( hide glue with hide glue, always)....you can get Franklin Hide glue at any good hardware store. If it's modern glue, then a good carpenters glue like Titebond or Elmers should be fine, just clean any old dried residue off the best you can with a chisel or scraper, dry fit the joints to make sure they fit well, and then glue and clamp the chair.I like those little disposable 'acid' brushes for applying the glue to the tenon and the mortise (hole)...apply the glue to both pieces, and then clean any squeeze out after clamping immediately with a damp paper towel and let dry. Hope that helps- post back if need be- regards- Greg

---------- FOLLOW-UP ----------

QUESTION: The joints are not broken, just loosened.

So, new wood glue will bond to old dried glue;
I mean the old glue that as penetrated the wood, dried, and cannot be scraped off?
I thought wood glue worked by penetrating the pores.

Is there a preferred sequence of disassembly? Are there any major “don’ts”?

ANSWER: New glue will stick fine to old glue, but it is important to remove any loose or crumbly old glue, but not too much....using the correct type of glue is important...always use what was on there originally...especially if it's Hide glue. Make sure everything fits well and fairly tightly, if a joint is worn and loose, glue alone will not make a lasting repair, and other tricks may have to be employed. Resist the urge to ever use epoxies on antiques (or any other furniture for that matter), as it is not a permanent solution as one might think, and if other repairs are needed down the road, (and they will be), it makes it very difficult to impossible to separate the joints to repair them, which needs to be done....even a well made piece of furniture will need regluing, and other services during it's lifetime, and good joinery, and tried and true glue types will allow the piece to survive in the hands of a good restorer, or knowledgeable repair person. Most joinery used in furniture is designed in such a way that it is reversible when needed, to facilitate repairs, or replacement of something broken.......hope that helps- Greg

---------- FOLLOW-UP ----------

QUESTION: You mentioned it is very important to use the glue type that was originally used.
You mentioned how to tell if it was hide glue, it is not hide glue, it doesn't become sticky when I wet my fingers and rub the tenons.

If it isn't hide glue what other choices are there besides carpenter glue; and how do I tell which is which.

I have been using epoxies on worn loose joints because it fills in the space...what are the tricks you refer to?

Answer
White glue and yellow glue fall into the PVA category of glues, and either would suffice....white glue (Elmers, WeldBond), will give you more time to assemble (open time), and will dry clear. Yellow Glue (Elmers Carpenters, Titebond, etc) will set up a bit faster and will dry yellow. Epoxies can be good for filling gaps, but as a general rule, I shy away from epoxy in furniture repairs unless there is no other solution. The key to a pieces longevity is being able to be repaired, and that means using an adhesive that is reversible down the road. Some of the tricks for tightening up a sloppy joint are using curls from a planed board to wrap around a spindle or tenon, (glued in place before reassembly), using small Oak or other hardwood wedges to wedge the tenon or spindle and then neatly chopping them of flush with the surrounding area with a sharp chisel...it's also important not to over analyze the repair,....normally just cleaning off any extra or loose glue from the tenon and the mortise, and then liberally brushing glue onto both surfaces, (while leaving enough in the socket to 'squeeze out') and reassembling and clamping should suffice...but it's important to treat the whole assembly, if one or two joints have loosened up, it's probable that others are too, and therefore complete disassembly and regluing is the usually the best route...