Thread: Best Joint for Ply Box (Bee Hive)

I have made heaps of nest boxes out of 19mm Hoop Pine plywood (external grade) using rebates cut on my tablesaw using a dado set.

I don't really see how finger joints would give a better constructed box and they would involve more work, certainly with a router. The finger joints would also involve more point for water ingress over a straight rebate.

Having said that, I don't know how bee boxes are constructed

I am not sure that the joints will be the issue of decay here. The weathering supers cop is crazy. I think that either way you go the first reason to replace a box will be because the corners are shot from sticking your hive tool in and out. I was speaking to someone just last week about this and she says that not even reenforcing the corners of the boxes helps. IMO a finger joint will be the best and quickest option and as long as the joints from the outside are properly protected, the box will break in other ways.

What sort of hive are you building?

I don't currently have a hive of my own but help tend to one at the college I work at. I'm spending some time building a 'Warre' hive, dovetail joints.

The local bee club recommends rebated corners as there is less end grain to weather and their slightly cheaper. Myself, I only use finger joints as my preference, and they tend to last circa 6-8 years.

My experience, having used both rebated and finger jointed corners, is that the finger jointed ones last longer. What's important is to thoroughly weatherproof them. Though you'll sometime find that the bees will modify them anyway. This is a link to one of my monitored hives (http://dl.dropboxusercontent.com/u/128833299/bees.htm) The dark mark at the corner of the hive is where the bees have found a small gap and rather than plugging it with propolis, have enlarged it and made a second entrance for themselves.

I'd also be wary of using plywood unless it is rated for outdoor/marine use. You might also want to consider what's been used on the timber/glue to make the plywood like that as the bees might prefer to not to live in those boxes.

Plywood

All the 60 odd 3 super hives I owned were made from plantation grown NZ pine
and were finger jointed!

I guess with modern glues - Titebond3 for example - and the availability of good
sealants then external grade ply with rebated joints is fine.

Where do you intend to keep this hive BTW??

@Moti. Fascinating. How did you do the bee count?

I've used a couple of these (https://www.sparkfun.com/products/9299) at the hive entrance. With hindsight, a few more would have helped as I suspect the limitation may have contributed to the bees making themselves the second entrance.

Plywood is only good for temporary boxes because if it was any good the commercial bee equipment manufacturers would be making their boxes out of it, but none are. Titebond 3 is good to seal and glue the joints. If you are doing a rabbeted joint you not only nail the end bits to the side bits but you then put nails through the sides into the end ply. The most important part when using ply is to seal the edges very well so that moisture does not get into the glued layers.

This subject has been much discussed on Beesource Forum which is USA based. You may have to become a member to conduct searches but it is a worthwhile forum.

What about a mitre/lock-mitre joint? No exposed end grain in those.

Thanks for the input and the links. I start with bees last November and have just started a 5 week Beekeeping course. The instructor is a beek with 57 years experience and says he will be teaching stuff we won't read in books! He has been making his hives from ply for 35 years and says they last just as long as solid timber are cheaper (1/3 the cost) and lighter. He uses butt joints but after reading some of the threads on Beesource I will go with rebate. Combining some of the discussion from Beesource and here finger joints leave the way open for water ingress and is probably why I have seen more finger jointed boxes rot at the corners than rebated.

I'm planning on painting the sheets before cutting out and then paint the joints on assembly. Copper Napthalate is an approved rot preventative for hive use but not cheap and usually dip the entire box. My thoughts are to just paint the cut edges with it as it will soak into the end grain of ply real good and seal with regular paint when it is dry.

Moti that takes all the fun out beekeeping

Originally Posted by Wombat2

Thanks for the input and the links. I start with bees last November and have just started a 5 week Beekeeping course. The instructor is a beek with 57 years experience and says he will be teaching stuff we won't read in books! He has been making his hives from ply for 35 years and says they last just as long as solid timber are cheaper (1/3 the cost) and lighter. He uses butt joints but after reading some of the threads on Beesource I will go with rebate. Combining some of the discussion from Beesource and here finger joints leave the way open for water ingress and is probably why I have seen more finger jointed boxes rot at the corners than rebated.

I'm planning on painting the sheets before cutting out and then paint the joints on assembly. Copper Napthalate is an approved rot preventative for hive use but not cheap and usually dip the entire box. My thoughts are to just paint the cut edges with it as it will soak into the end grain of ply real good and seal with regular paint when it is dry.

Moti that takes all the fun out beekeeping

Does he copper napthanate the ply or only the ends like you intend to do? What thickness are you using?

Originally Posted by Kidbee

Does he copper napthanate the ply or only the ends like you intend to do? What thickness are you using?

No he doesn't treat with Copper Naphthalate just gives 3 coats of paint external and two internal. Going to use 19mm ends and 15mm sides- structural ply - the glue is supposed to be stronger and using construction adhesive which is designed to glue ply and flex with humidity changes. We are borderline sub-tropical/ tropical so heat and humidity are our main concerns.

Bees are incredibly adaptable, and sometimes I think we over fuss too much. By way of example, I have one 5 frame nuc that I knocked up with scrap red tongue flooring chipboard 7(?) years ago. It's painted, is always outside in the weather, and has no problems.

I never paint the insides of hives.

With that ply they are going to be pretty heavy supers let 'em get full of honey and they will test your mettle.!!

What are you doing for an extractor?