Replies

1. 
   JohnWW | May 03, 2007 03:24pm | #1

   Glue the broken off tenon end back on first and then bore through the reassembled tenon after the glue has dried. 

   It is very difficult to get a clean round bore through end grain, a large brad pointed twist drill is probably the best tool for the job, a spade bit will chew up the hole badly.  An auger bit of the type used by electricians would be another good choice but the feed screw probably won't work in end grain.

   Ideally you can bore the hole with a drill press or on a lathe, drilling freehand will be difficult and the hole will wander and come out oversize.  I'd drill with a 1" bit, drilling a 1 1/4" hole through a 1 1/2" tenon will leave you little room for error and the remaining hollow stub will be fragile. Finish the repair with a hardwood dowel using epoxy which has good gap filling properties.

   Two alternatives: 

   1.  Drill a 1/1/2" hole in the rail and install a new tenon rather than trying to save the shell of the old one, simpler and stronger but the repair might be visible, but it isn't in a highly visible location.

   2. Glue on the old tenon stub and then drill through the center and install a 5" to 6" long 3/4" lag bolt, this is probably the strongest repair.  Be sure to drill a clearance hole for the unthreaded upper part of the bolt and a deeper undersized hole for the threads.  For even more strength, apply epoxy to the bolt and hole when you run in the bolt.  This is the repair I'd use, it would be much stronger than the all wood fix.

   John White, Shop Manager, Fine Woodworking Magazine 

1. 
   RDNZL | May 04, 2007 04:43am | #4

   Hi John

   Once again, you have indeed given excellent advice. The lag solution is what I will attempt, barring someone else coming up with something brilliant.

   This particular solution also answers another of my concerns: that of isolating and removing the broken rail with its several cross member joints. I believe that I can do a lag repair on site, using portable power tools.

   What remains to be seen, of course, is whether or not there is glue in the broken joint, and thus whether or not the tenon stub will come out whole, and just how well the splintered ends will go back together.

   I have read here several condemnations of the ubiquitous hardware store epoxis - I could of course order in a more advanced/specialized (and presumably more expensive, although that's a minor quibble) epoxy, but is it necessary in this instance?

   One other thought, although I suspect I could find a solution when the time comes, is that now that the repaired tenon has a core of steel, how does one (other than "verrrry carefully") then run a screw through it to secure it in the mortice? From my fairly cursory inspection, I suspect that the aforementioned screws are the primary locking mechanism in these joints....not that I need follow suit, of course.

   Thanks for your input!

1. 
   JohnWW | May 04, 2007 03:50pm | #5

   The epoxy is just a bit of extra insurance and a gap filler in this application so a hardware store version should be fine.  Don't forget that the bolt head, with a washer under it, on the end of the tenon will make the tenon a bit longer.  You may have to deepen the hole or shorten the tenon a bit before you install the bolt so the tenon will seat fully in the post.

   If the break was clean you may find that the stub will fit back on almost seamlessly once you get the proper alignment.  If a lot of the fibers were crushed and compacted, refitting the stub may not be practical, good luck on that one.

   Reattaching the rail to the post will require some field engineering on your part, without seeing the details I can't offer any advice.  Of course if the stub is glued in you will have a whole different set of problems.  Hopefully if it is glued the job wasn't well done and you can work the stub free, but it is more likely that you will have to bore it out and make a new replacement tenon on the rail, a much bigger job.  Hopefully you are getting paid by the hour for this.

   Good Luck, John W.

1. 
   RDNZL | May 17, 2007 04:50am | #6

   Hi John (and all interested)

   For what it's worth, it's done. Got the go ahead, accomplished the task in about 5 hrs. (And yes, it was by the hour....)

   I had intended to do this on site, but came back from the weekend and the weekend crew had brought the whole thing to my shop....as it turned out, it was just as well.

   Yes, there was glue in the joints, but fortunately for me, not much. One tenon stub came out fairly easily, and essentially whole by running a screw into it and levering it out with the claw of a hammer. The other was more difficult - same technique, but lots more effort, and only part of it finally came out. Had to break the rest of it free with a narrow chisel, and it finally came free in two additional pieces.

   I glued all three pieces back together with yellow glue, clamping with rubber bands. I then dry fitted the stubs to the splintered ends of the rails (pretty good fits - 1 tenon missing some significant chunks, however) dimpled a center, and countersunk for the lag head and washer with a forstner bit. I bored to shoulder depth with a 3/8 twist bit (no brad point available - mine were at home), then bored to full depth with a 5/16 extended length twist bit.

   I then painted both stub and rail ends with epoxi, refitted the stubs and slowly ran in a 6" x 3/8 lag until it just bottomed out. Some bondo type filler repaired the missing chunks, and it was left to sit overnight.

   Today, I toted all parts back (third floor, and all the way to the end, naturally....) and reassembled it in place. Each joint was liberally coated with epoxi, mortice and tenon both, and beat into place with a deadblow hammer. The original screws were inserted into the unrepaired side, the repaired side, with its steel cored tenons, after some inspection and consideration, were left alone, relying entirely on the epoxi.

   Only time will tell, now. The owners refused my recommendation of some serious furniture glides - they'll take care of that themselves (!!!....) I did put a sticker on the underside dating the repair and noting that I would not repair this bed again, at least not this same problem.

   Thanks for your help John. 

1. 
   JohnWW | May 17, 2007 04:28pm | #7

   The repair is probably stronger than new.  The most likely problem will be one of the other joints failing, and you know who they'll call when that happens.

   John W.

2. 
   RDNZL | May 18, 2007 02:02am | #8

   You've got it John!

   Not to drag out a mundane post, but the scenario is this: two of these double beds in a room meant for one, deep pile carpet on the floor, and regular housekeeping service in a rental situation.

   I'm quite sure it was the housekeepers that broke it originally, trying to drag it over that carpet so that they could get at the sides to change the linens, thus my recommendation of the furniture glides - what I found would have gone a long way towards ameliorating the problem, but these folks will probably try to stick a few of those nail on button type things on and think they've saved a couple of bucks.....

   I think it's called job security.

2. 
   joinerswork | May 03, 2007 11:58pm | #2

   RD,

   JohnWW has given you good advice.  I'd go with his 2d option, if the larger dia tenon sheared off once, what's to keep a smaller dia wooden repair from doing the same? 

   Ray 

3. 
   [email protected] | May 04, 2007 04:36am | #3

   I would probably go with John's second method, but put in a piece of steel pipe.  If possible the "gas" pipe with the hard plastic coating. 

   For drilling I would try a forstner bit, and put an extension on it to get the depth, you should only need to get 8-inches or so past the break. 

   This coated gas pipe works well for pipe clamps, and the coating keeps it from staining the wood, so I you had to buy extra to get the repair piece it wouldn't be a waste.