Replies

1. 
   Danford_C_ | May 01, 2002 10:42am | #1

   Ray,

   1: How can I best get water into the joints without damaging the finish or harming the wood in any way? Should I apply steam to the surface, drill a small hole and inject water through a hypodermic needle, or is there a better method?

   Use a syringe filled with hot water, no drilling should be required.

   2: Is the injectable product which claims to glue as well as permanantly swell the wood fibers a good alternative to disassembly and restoration of the hide glue?

   Which product would that be?

   3: When disassembled, if the dowells fit loosely, would it be a good idea to use a urathane glue with space filling properties in place of the hide glue?

   Not in my opinion, I would remake the dowels.  Typically, though, a tenon was used, if this is the case, cut off the existing tenon flush with the end, then bore a slightly oversize mortise in both pieces and use a dowel of the corresponding diameter.

   Dano

   "Form and Function are One" - Frank L. Wright
1. 
   JRayRitzman | May 01, 2002 06:41pm | #2

   Thank you for your reply, Dano!

   The substance I referred to in the earlier note is called "Chair Doctor". It is apparently and acrylic glue mixed with a substance to swell fibers. It would appear to me to be unwise to use it in a hide glue joint, but the guy at the Woodcraft store says it will work.

   With reference to cutting off a tenon and drilling a mortice in each piece, how do you align your holes so they end up along the same axis?

   I always seem to get my drill tilted one way or the other unless I can use a drill press or some sort of guide. Some of these parts meet at unusual angles.

   I can see how hot water from a syringe would trickle into a loose joint. But if I need to loose an intact joint, I have trouble seeing how the water might get in there without soaking for sometime. Would it be a good repair if I were to just wet the loose joints, and perhaps inject a little liquid hide glue, rather than taking them apart?

1. 
   Danford_C_ | May 02, 2002 07:36am | #3

   Ray,

   I've never heard of "Chair Doctor" so I can't really comment on it.

   A drill press would definetly help for accuracy, though it can be done by hand; just like they did it before they were invented.  I used to use a brace for such work with a Jennings type auger bit.  So, you find the center point on the the piece that had the tenon and bore away.  The existing mortise is more challenging, I would use a twist bit in the brace, some prefer a spoon bit.

   Injecting the joint with a syringe rarely works with just one injection.  Usually you have to make several around the joint, patience is key.   I suppose one could try injecting hide glue into the joint but, it wouldn't last very long at all.  The best thing to do, IMHO, is to seperate the pieces and go from there.

   Dano"Form and Function are One" - Frank L. Wright

1. 
   JRayRitzman | May 02, 2002 06:40pm | #4

   Thanks, Dano!

2. 
   gerry001 | May 24, 2002 02:48pm | #5

   IMO, Chair Doctor will work best if the joint is only a little loose, so that the small amount of swelling it adds will lock the joint, as it has no gap filling properties. It will also be much more brittle than hide glue.

   Getting and keeping a drill (or chisel, or whatever) aligned is always a problem, so give yourself a visual guide. Clamp a square or a stick or rod or something to the work, carefully arranging it to present the proper angle, and such that it will be close to but not touching the axis of your tool. When drilling just watch the drill versus your guide.

   For the joint separation, I agree with Ray. You need patience and work into it. You can mask surrounding areas to keep them from getting wet. In the worst case, only the inside of the joint is loose, and the glue is still solid on the outside. Usually, some work and flexing will crack the outside glue seal. If not, I use a small drill bit the same size as the needle, drilling into the joint, but that's rarely needed.

   Gerry