View Full Version : Strongest type of joint
02-13-2001, 12:46 AM
What is the strongest type of joint?
I am looking to build a chest to use as a humidor. Since the inside of the chest will be kept at 70% relative humidity, the stresses on the chest will be great.
I have heard there are joints stronger than the dove tail but am not sure if this is true.
Thanks for the info.
02-13-2001, 01:16 AM
For a box type of application I think that the dovetail is the right joint. Look for Issue 127 Dec 97 of Fine Woodworking. They had a big artical on building humidors.
02-13-2001, 10:11 AM
I just finished a humidor box for a guy at work.
I agree with Lou, and used a tight dovetail with Gorilla glue.
One important note: I moistened the wood were the glue was to be applied.
Polymere glues require moisture in the wood to catalist correctly. They react to the moisture and set properly.
Also, you MUST clamp the joints until the glue has completed setting. The instructions and a world of information is available on the glues site.
I think it's gorillaglue.com or something like that. Many folks don't take the time to read the products info and get half-a__ed
The moisture is the key. I brushed the joints with water from the RO spicket on the sink. Clean water.
See johns box in the projects page of my site.
Also there's a close-up of the dovetail. I made 10-12 joints in 3/4" MDF before I clamped his fine mahogany in the dovetail jig. To be sure I had the bit set right and could do the joints to MY satisfaction. They took force to put together, were bottemed well, and then sanded to flush a day after the glueing. (Mustn't rush quality work!)
I also pointed out to John that the nature of the application may in fact be the culprate to failure.
It's like laying a board on the ground. The bottem is moist and the top drys out, mechanically I can think of little more that could be more stressful to the fine wood and labor going into such a project.
I suggested he get an old fridge or maybe an old aquarium to put the humidor control in and then put the box into this chamber so the humidity is equal inside AND outside of the box.
John plans to line it with Spanish cedar and do inlaying on the top.
Should be gorgious when he gets it done! When that happens, I'll post a picture of it.
Roger S. Dillman
02-15-2001, 12:31 PM
I agree that poly glue is the answer to achieve air-tight joints.
The only thing to add,if you don't have the capacity to cut dovetails,consider box joints. Carefully cut,they would work just as well. It is air-tightening you are worried about,there wouldn't be that much stress on the sides.
02-15-2001, 06:14 PM
Yep, I would have liked to have used a box joint on the one I put together.
But the nature of what these affectionadoes do to the poor wood is extreem.
I told John, the guy I put it together for, it was like laying a board on the lawn and having the sun beat down on it from above.
70% humidity on the inside, and whatever on the outside.
Jeeze, the inside is growing and the outside is drying out.
It's a tough call if anything will hold up, reguardless of the joint or glue used, to my way of thinking.
If the joints hold, the lid may warp, if all that is good the wood itself may split. Good golly Miss Molly!
Dave in Cairns
02-17-2001, 02:19 AM
This differential in humidity is the very reason that the majority of humidors are made from MDF with veneer. They can be made with solid timber BUT and its a big but , the timber must be prepared correctly. To build a box and then expect it to take 72 - 75% RH inside (optimum for cigar storage) while it's sitting in a centrally heated environment at say 10% RH is a big ask of any timber regardless of joints or glue used. The timber must be prepared correctly . IE , the timber must be at these RH prior to planing ,cutting and jointing. Using timber @ say 10% moisture, to build a box , then introducing a 72% RH environment to the inside only just isn't going to work . It is also most important to use the correct ratio of Spanish Cedar for the volume of the humidor . This will ensure that the end product is balanced and doesn't require constant attention to keep the optimum conditions. This one below in blackbean keeps a constant 73% for over 2 months without adjustment or fiddling with the humidification unit. More views of this can be seen by clicking on the image.
02-18-2001, 01:28 PM
Dove tail joints are strong, but, I think "Bear Head" joints are much stronger. Check them out.