Re: building a sauna
The glues in plywood are a nightmare!
your husband would do well to be careful even cutting it with a skilsaw.[wear a mask and if possible, cut it outside in fresh air]
The other two replies are right on the money - heating it releases the gases of the glues, and they are special glues, very toxic. A google search will likely find some info.
Thats why Cedar is used, or some type of whole wood planking/slab type.
I also have a IR sauna! I built it myself, here is some hints:
No wood at all!! - I draped the frame with sheets, and oddly enough it heats up to 40C. in just 10 minutes.
Frame - Use aluminum square tubing, about 1" or less is enough strength.
Attach the "emittors" [heaters] onto electic boxes, and fasten [screw] those boxes to the frame.
Use wire called BX - it is in a aluminum wrapping.[#12][the insulation of wire is bad too, esp when heated, but when it is in this "BX", and run behind the heaters [emittors], does not even get warm.
Make the sauna as small as you need for better effect - I made mine a "one-man" size, about 5' [feet] tall, and 5' wide, with 6 or 7 emittors in the arrangement of four facing you, two behind pointing at the spine, and maybe one more emittor low down behind you[the 7th one, which I dont allways use].ZANG!!!
Questions? [my e-mail is not working right now, but send me an e-mail and I will get it eventually - kvi354@telus.net]
karlin