Plywood supers?

Plywood is manufactured with a variety of different glues and exposure ratings - specifically, all 3/4" pine plywood is not the same.

More here: http://www.apawood.org/level_b.cfm?content=srv_help_prd_extexp

I understand that, and thats one reason for asking the question. If you couldnt verify the source of the plywood would you use it for honey supers? I dont see a problem with using it for nucs but if some of you do know o a problem please let me know

If the plywood does not have a grade stamp then its tough to tell what it is.

Free or really inexpensive materials have a powerful pull for me. I'd first use up the plywood in any tops I might need, but then use it for hive bodies. Since the plywood may not last as long as solid wood, improve your odds by painting all sides, including the inside of the hive body.

I am aware that some may consider painting the inside of a hive body to be heretical advice, but since Barry does that how can one object?

Also, if you are serious about maximum life, before painting, brush a layer of Titebond on the exposed cut edges of the plywood (including the frame rests) and let it dry. If you do this, you can skip painting those edges, IMHO.

And don't forget the Titebond in assembling the hive bodies!

a lot of the plywood used for cabinet work such as pine, birch, oak or maple is made with interior glue. this is not suitable for beehives unless you know that it has exterior glue.

ive mde a few plywood supers. but, they havent been used yet for supers. they seem to be just over flow if i run out of supers duing a flow....which would be nice hahha. im thinking of using them for medium brood boxes instead...not sure. i have been using medium plywood boxes for nuc supers though and they work great. i heavily paint them every year and no complaints.

I ended up making 10- 5 frame nucs out of the plywood. I cut half lap joints for the front and back. I used a 3/8' half lap joint for the fronts and backs. I cut a 3/4" deep lap joint on each side and the bottom side of the back. The bottom will have no exposed sides and each side will have 3/8" of exposed area all the way around the bottom. The bottom has a 3" landing board so there will be 3/4" exposed ends on that. I will paint glue over all the exposed areas. I got the fronts, backs and sides all glued up and assembled this afternoon. I cut the bottoms and painted the inside surface of the bottom and I will finish up putting them together tomorrow after church. I bought 30 pieces of the plywood and they ended up being 11"x44" long. I will have about 5 or 6 pieces left after making the migratory tops for the nucs. So, I will have $25 of materials in 10 nucs. I will use some of them as swarm traps and some as nucs.

I use plywood with no problems

Most of my supers are plywood. Prime and paint, let the bees seal the inside. No problems.

http://www.saunalahti.fi/lunden/page10.html

Here some pictures of my plywood boxes. They have been in use for over 20 years, no problems, just more paint.

they were made from second grade stuff, but surely it was a risky choise, but the price was low...

mine are 3/4 birch...brood chambers and supers......been using them for 2 years....cost me all of $2 a box for glue,screws and time....sure is nice to get FREE stuff......cuase FREE is always in the budget.

Thanks for the replies.