glue question for end grain

[larry merlau]

i have a letter opener that my daughter got for better half, its made with paduk and i think rosewood maybe teak, but the criter broke and she is beside herself she wants me to fix it:eek: well the joint is end grain to end grain and its only 3/16 wide by 3/4 to a inch long joint.. what glue would you suggest. i dont think i could reinforce it with a spline to get long grain i might be able to drill a hole in both pieces to try and get a loose tenon effect but i gota be careful or she will have me for lunch:D help this ole caghger out if you can thanks.

[Steve Schoene]

End grain to end grain just wont work. The solution is to create a scarf joint, where each side is tapered so that the parts both have almost flat grain. You will lose some length unless you scarf in an extra piece.

Another alternative is to make a replacement from scratch. Probably not too huge a project. (Sort of like slipping in a new gold fish, when the first ended up floating belly up.)

[larry merlau]

steve this does have that idea somewhat but only a 1/4" on each end of the joint, its actually kinda like a s curve but real small

[Andy Hoyt]

50/50 mix of white glue and water. Coat the end grain and let dry. Recoat, join peices and rub back and forth ever so slightly, and then it'll lock up tight on you. Suggest you practice on scrap first so you'll know the rubbing time involved so that you'll get a proper peice alignment

[Steve Schoene]

Can you post a picture of the letter opener with the break?

And I would be extremely sceptical of being able to get a rubbed joint that would hold, using white glue. If you want to try that use hot hide glue, its quite a bit stronger than white or yellow glue. But for any glue, the parts must fit together tightly.

[Andy Hoyt]

I was skeptical too Steve. But I watched the process demo'd. Seconds after the assembly was made, it got mounted on a lathe and endured some very serious cutting. Tried it at home, and yup, without a doubt it is stout.

[Steve Schoene]

But Andy, he has such a small glue area it would be best to go with the stronger glue, one that has a very good track record with rubbed joints. That's the hot hide glue. There are rubbed glue blocks that have remained in place , glued cross grain, for two centuries.

Even so, without mechanical connection and even with pre-priming the end grain, I wouldn't bet a nickle for success with an area that small.

Perhaps you could splint the break with fine wood slivers, wrapping them with fine silk or nylon thread--say 00 size (from fly fishing shops, used for fly tying). When varnished the thread would almost disappear. The splints could be fiberglas threads, so they would also disappear when varnished. There would only be a small thickening at the location. Pretty far fetched, but it could work.

[Norman Hitt]

Larry, could you drill one or two real small holes in each piece and clip a couple of pin nails to length and use epoxy glue to glue in the pins and to glue the joint together? The pins would keep it aligned and add strength and the epoxy would be the toughest glue for end grain anyhow.

[Ian Abraham]

I agree with Norman, break out the dremel and drill a couple of small holes in each piece, cut the heads of a couple of small machine screws that will be a loose fit in the holes. Dip the ends in epoxy and insert these into the holes and a bit more epoxy to hold things together / fill the crack. The epoxy will hold the threaded rod in the holes and fill the gaps. Because the pins are loose fit you can adjust the two pieces to match up again and then let the epoxy set.

Cheers

Ian

[Lopaka Garcia]

Andy, do you think that rubbing technique would work on picture frame joint? The 45 angle is still pretty much end grain so I wonder if it would work on that? Is it a lasting hold, or just temporary?

[Andy Hoyt]

Lopaka - I don't see why not. But the alignment issue is key. And read on.

Steve - I am reminded that diminished reading comprehension skills are an early sign of dementia. Got so excited about the notion that I could actually help someone that I didn't note that the cross section size was so small. The two pieces I saw glued together had section size of a beer can (+/-). I defer to your wisdom.

[larry merlau]

Larry, could you drill one or two real small holes in each piece and clip a couple of pin nails to length and use epoxy glue to glue in the pins and to glue the joint together? The pins would keep it aligned and add strength and the epoxy would be the toughest glue for end grain anyhow.

well norman i had thought of that option and ended up doing that, used some no.4 finish nail rather than pins and some 2 part epoxy feels good havnt used it will let ther try her hand at breaking it again:) as for remaking it, that wasnt an option it had at least 5 other woods in it on the handle part to make a picture or sorta like marguetry. so its ready for round two thansk for the suggestions.

[Steve Ash]

I was gonna suggest duct tape :D Glad you got it fixed Larry.

[Lopaka Garcia]

I made a bunch of picture frames out of Koa and was planning on using some sort of strengthening device such as corner splines or those W type connectors picture framers use. Well one of my frames came out misaligned out of the clamp and I was going to break the glue joint and redo it. But when I tried to break the glue joint, boy if I couldn't break it as hard as I pulled and I'm a big guy. Then I put it on the workbench and tried hitting it and it still wouldn't break! So now I'm thinking, hey this is some pretty strong stuff, why would I need to add more strength! It's only going to be hung on the wall. But now I'm thinking what will happen in the future when there's slight movement in the wood? Will that be enough to break the glue joint?