Bees killing my boxes

[Rayban]

Ok. So a couple months ago I built several bee hive boxes with kiln dried yellow pine. I used box joints and Titebond III glue. I also put a nail in the end of the box in each of the second joints (four nails per end, one joint up from bottom and down from top). I did not put any nails in the sides. Outsides of the boxes are stained with Olympic stain and sealer and a top coat of clear Olympic sealer. No sealer inside which is typical of beehives.

New bees showed up a little earlier than I expected so I had to take a few boxes straight from the shop outside to hive the bees. When bees first start out, you feed them sugar water and they evaporate it along with nectar inside the hive. As such, during the Spring and Fall, a lot of humidity is generated inside the hive during the evaporation process. Although, there is some venting through the entrance and out a ventilation hole near the top.

Boxes have been on the hive for almost a week now and the side rails are starting to cup. I'll try to post a photo showing what is happening to the top and bottom joints. I haven't had this happen to boxes in the past so I'm looking for suggestions on what to do differently or what to do with the ones on the hive. I had a single box on the hive starting two weeks ago that did the same thing. I moved the bees out of that box and into these, which they don't like very well and I now will have to move them again into another box. Once I brought the first box back into conditioned space, the joints closed back up for the most part and I added additional nails to the sides. I haven't put that first box back on yet to know whether that will solve the problem. I know the inside high levels of moisture are causing the problems and I can see the cupping stops at the level where the original four nails were installed. I would appreciate any advice you may have. Thanks.

 

[Endless Pursuit]

1 side sealed + other side bare= worst case for moisture movement. Quarter sawn boards would help.

When I built my hives several years ago I did not use any nails, just exterior glue. But I used QS pine. I never had warpage like shown in your photos and I fed twice a year, heavily in late winter/pre-spring. My gut, and the rift grain on the finger ends tells me it's the board(s).

With all the natural food right now, you should be able to take the syrup tanks out.

 

[junquecol]

When I had bees (50 hives) I built my hive bodies using white pine. Rabbet ends, painted (latex) with what ever color I could get for almost free from Lowes. Bees will quickly coat inside of bodies with wax / propalous. Never had problem with warping. But my wood sat outside for almost a year before building hive bodies, so it was at equilibrium with moisture in air. As far as humidity in hive body, bees keep air flow going to keep hive dry inside.

 

[Bob Carreiro]

No bee experience here, so...
Can you remove the exterior finish - run a belt slander over it or..? Also, if possible with bees, can you drill a series of small holes around the perimeter of the boxes to aid in moisurebuild-up??

 

[chris_goris]

It looks to me like moisture, a locking type of joint would be a better selection next time, like a dovetail or even a lock miter.

 

[scsmith42]

Your problem is that the mc% of the wood in your conditioned shop is much lower than the mc% of wood stored outside. Wood is hygroscopic and always tries to reach equilibrium with its environment (called equilibrium moisture content or EMC for short).

The EMC of wood stored in a conditioned space in the winter is around 6%. The EMC of wood outdoors is 14%~16%, and as the wood gains moisture it expands.

Since your hives are finished on the outside, they are only gaining moisture in the inside, which causes the wood cells to swell on that side and cup the board to the outside.

There are two potential solutions. Either store your hive wood out of doors before and during the build process, or place the finished hives out of doors for a few weeks before finishing.


Scott

 

[Jeff]

+1 to EMC issues and cupping, but this doesn't have to be fine woodworking for a fluctuating exterior environment.

It may be ugly from a woodworking perspective but that's of no consequence to the bees or their use of the hive. Leave the boxes alone and tend to the bees. No exterior finish is needed but that's a done deal now.

and I can see the cupping stops at the level where the original four nails were installed.

Nails or not 1/3 of each glue joint is face grain to end grain which is a bit weaker, but not necessarily a show stopper. The nails have anchored the innermost joints in the end grain and the cupping is at the extreme ends as you've noted.

BTW, I'm expecting a package of about 3,000 bees any day for my second year in this venture. ccasion1

 

[AllanD]

I agree with most of above except I doubt you will see that much difference whether you finish outside or not so I would continue to finish the outside so the hive lasts longer. If you have open water dishes evaporating inside it's gonna move. The wood will move along the growth rings regardless so above all: don't fight it, don't try more nails, etc. They will come out. If you try to lock the wood with other joints chances are it will crack. Jeff has the best advice which is use QS wood. If you can't use only QS, the other thing would be to start with thicker wood than you need, let it acclimate to high moisture, mill it at that point and assemble. Of course if you then have it in a much drier environment for a while the center of the side will tend to open.

 

[Willemjm]

I'm not a fan of Titebond III, but will great to know how long the glue cured and under what temperatures was the glue allowed to cure?

 

[scsmith42]

I agree with most of above except I doubt you will see that much difference whether you finish outside or not so I would continue to finish the outside so the hive lasts longer. If you have open water dishes evaporating inside it's gonna move. The wood will move along the growth rings regardless so above all: don't fight it, don't try more nails, etc. They will come out. If you try to lock the wood with other joints chances are it will crack. Jeff has the best advice which is use QS wood. If you can't use only QS, the other thing would be to start with thicker wood than you need, let it acclimate to high moisture, mill it at that point and assemble. Of course if you then have it in a much drier environment for a while the center of the side will tend to open.

I probably should have said "out of doors" instead of "outside" in my post, since it is easy to confuse "outside" the hive with my actual intent; "outside the shop". I have corrected my post.


Scott

 

[Rayban]

Your problem is that the mc% of the wood in your conditioned shop is much lower than the mc% of wood stored outside. Wood is hygroscopic and always tries to reach equilibrium with its environment (called equilibrium moisture content or EMC for short).

The EMC of wood stored in a conditioned space in the winter is around 6%. The EMC of wood outdoors is 14%~16%, and as the wood gains moisture it expands.

Since your hives are finished on the outside, they are only gaining moisture in the inside, which causes the wood cells to swell on that side and cup the board to the outside.

There are two potential solutions. Either store your hive wood out of doors before and during the build process, or place the finished hives out of doors for a few weeks before finishing.


Scott

Thanks. I also have a couple hundred board feet of cypress that I plan to make the next boxes with. I thought about just air drying to EC and not sending it to the kiln. Any problems with that approach?

 

[Rayban]

I'm not a fan of Titebond III, but will great to know how long the glue cured and under what temperatures was the glue allowed to cure?

Glue cured for about two weeks in a conditioned, 65 degree shop.

 

[Rayban]

+1 to EMC issues and cupping, but this doesn't have to be fine woodworking for a fluctuating exterior environment.

It may be ugly from a woodworking perspective but that's of no consequence to the bees or their use of the hive. Leave the boxes alone and tend to the bees. No exterior finish is needed but that's a done deal now.



Nails or not 1/3 of each glue joint is face grain to end grain which is a bit weaker, but not necessarily a show stopper. The nails have anchored the innermost joints in the end grain and the cupping is at the extreme ends as you've noted.

BTW, I'm expecting a package of about 3,000 bees any day for my second year in this venture. ccasion1

Thanks. I'm in town though and the hives are visible. I prefer not to have ugly boxes. That's just one more reason for folks to complain. G

Good luck with the bees. I have four hives, two new packages recently installed and two nucs on the way in April. I will probably split the four established hives at summer solstice.....meaning, I need more boxes soon. I hope to limp through with these until I can build more.

 

[scsmith42]

Thanks. I also have a couple hundred board feet of cypress that I plan to make the next boxes with. I thought about just air drying to EC and not sending it to the kiln. Any problems with that approach?

Nope. Good approach.,even if you kiln it to sterilize the lumber simply store it out of doors for a few weeks so that it will stabilize back to around 15% mc. Then do your layout and cuts.


Scott

 

[Jeff]

Thanks. I'm in town though and the hives are visible. I prefer not to have ugly boxes. That's just one more reason for folks to complain.

Gotcha. Have they ever complained about bees in the backyard (finished boxes or not)? It's good to be sensitive to local reaction-too many scary films about "killer" bees.

http://en.wikipedia.org/wiki/List_of_natural_horror_films#Bees

Thanks. I also have a couple hundred board feet of cypress that I plan to make the next boxes with. I thought about just air drying to EC and not sending it to the kiln. Any problems with that approach?

I used 1" t cypress for this top bar hive about 1 year ago. Nuts, bolts, and stainless steel screws. I haven't noticed any wood movement issues and there is no glue used.

​

 

[CrealBilly]

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When I do fancy box joints like that on something I know is going to be outside. I pin the joints all the way through. A pin can be a long bolt cut to length or length of steel rod. Its not going to stop a board from cupping but it will help keep the joint from separating like yours have done. Also helpful for me is to understand how a flatsawn board will cup. I use the idiot system to remember. Idiot = inside drawer outside of tree. OK not really idiot but close enough.

Here is a visual of how different cuts of lumber will move. Note your most stable is quarter sawn bottom left, then rift sawn right above on the left, flat sawn shown on the top is the most unstable. Also note the direction both flat and rift sawn boards cup (to the outside of the tree)

Your boards appear to be rift sawn but look to be put together backwards. They are cupping towards the outside of the tree like they should. When they cup there is noting but air to hold them in place. Had you turned the boars over so the inside is to the outside of the tree, the board would meet resistance of the other board when it cupped and would not have been so bad.

I really dont use flatsawn lumber anymore for the very reason you have shown. Unless its for construction and then its crappy pine so its not a big deal if it cups anyways. Just remember to nail the outside of the tree down to whatever your nailing it to.

I hope this has helped some.

Calm seas never made a good Capitan

 

[Rayban]

Thanks to all.

Btw, that's a nice looking top bar.

 

[gritz]

My dad kept bees. He only used air dried cypress for his boxes, plus he painted the exterior white to help regulate interior temperatures. The bees will seal the cracks I see in yours, as they do in the wild. Keep using those, but make the next ones from cypress.