Suggestions on how to open a 16 year old dovetail joint
darboux
| Posted in General Discussion on
I built a maple hanging cradle for my first grandchild. The side rails join to the head/foot board by dovetails. Unfortunately I ran the grain of the end board the wrong way and it has now split. I want to replace it. That means opening the dovetail joints. I used either white or yellow glue at the time (probably white). Does anyone have experience with encouraging old joints to open up? Any other potential solutions will also be appreciated.
Replies
why not show us a picture of the damage and what you want to disassemble
You are right I should have included a picture. There was an option to do that as I prepared the post, but now I do not see a way to add the picture to this comment. If you know how that can be done, let me know and I will post a couple of pictures.
Darboux
I don't know yet how to
I don't know yet how to attach a picture either, but will. there is usually more than one answer for a given problem given the construction of the project
1. is the crack going to affect anything?..]there are times to live with a crack and others expect perfection from a piece of wood that is always going to move
2.perhaps just a fine cut into the crack and insert a skip into it and clean it up. minimal repair to everything inc finish. as someone else mentioned put some glue in and clamp, that is always a badage and never lasts
3. take it apart and repair or replace the peice and put it back together. not knowing the climate that it is in also makes it more difficult to diagnose; if it is a dry climate esp in winter, you will know that you can knock it apart easier without to much damage
the vinegar will only go a minimal distance into a tight joint and the moisture content if it does will also tighten the joint
some people make fairly tight dovetails while others can be quite sloppy ensuring that it will come apart easier.
you may have to accept other damage to repair when you take it apart. that is the risk of it.
if it was built properly one should be able to take it apart without to much damage. "if" is the biggest part. this is why a pic makes it easier to analyse
it may not have to come apart to be repaired
ron
Thanks for your comments, Sid Works. I got a number of suggestions that I am just going to have to try. The head/foot boards definitely need to be replaced. No repair that I make will hold up given the way I ran the grain. I know better now but I built this for my first grandchild 16 years ago. So it is important to me to get it right. I hope that my great grandchildren will use the cradle.
I'll start with the vinegar and see how that goes. then work up to the more definitive moves. At worst cutting and chiseling out the dovetails should be doable, if tedious.
I'll keep your note in mind and when I get the thing apart, I'll write to tell you how my saga went.
Darboux
a good hammer and a block of wood with a solid grounding underneath usually knocks them apart'
I have been doing this now for 35 years
ron
try to inject vinegar and soak the glue line -
SA
Yep,
1. Vinegar and water
2. Time to work
3. Gentle persuasion with a deadblow hammer.
Why not fill the crack with cyanoacrylate adhesive with a spray hardener and let it be as it was.. Clamp it quickly!
darb,
You say you ran the grain the wrong way. If that means you are going to replace it with another piece, it might be as easy to saw the split piece out near the joint, and carefully saw/split/chisel the waste out of the joints.
Ray
Thank you. This is an excellent idea. Two other people suggested soaking in vinegar/water solution then trying to work at the joint to pull it apart. It may be that a hybrid of that approach with yours will be called for.
Darboux
Sorry if this is too late.......
I'm not wild about the idea of water or vinegar. Although either/both will often the glue. either will also swell the wood. And swollen joints are tight joints.
Like Hammer1 said -- use heat. In some cases, a heating pad wrapped tightly, or a hair dryer is enough. In other cases, you need a heat gun. If you use the heat gun, be careful not to char the wood.
I take things apart quite often. A heat gun works wonders on just about any glued joint. It's possible a hair dryer would generate enough safe heat but I haven't tried it.
I was just going to add the heat idea. I do know from personal experience that biscuit joints made with titebond and titebond II will pull apart with stiff hand force if left in direct sun on a 100 degree day. The wood in question was just to the point it was too hot to comfortably hold with a bare hand.
Heat gun, have done it hundreds of times on whit and all of the yellow glues
HM
Thanks lads,will remember your tips too.
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