Carpentry and Woodworking - Glue for beams?

Okay, no bites yet on the question about laminating my staircase beams, so how about advice as to the best glue for such a project? I would be gluing cypress 2x8's to pine 2x12's, or perhaps sandwiching a layer of plywood between two cypress planks to create the needed size, instead. I've seen many examples of laminating lumber for furniture projects on DIY shows, but don't recall which glues were recommended. This shouldn't be much different than creating my ridge beam from 3 2x12's, except for that project I used liquid nails and spikes, not the look I want for this project. Any suggestions?

I've read your other post, but haven't been able to justify or refute what you plan to do. Several things come into play. If you use syp, plywood and cypress, and this is an exposed staircase, as I would imagine it to be, you will be able to see the laminatation, and it would be unsightly. Yes, it would probably be stronger than what the original design called for, but in a log home, exposure is paramount. You may exceed the strength requirements by building a lam, but only having a total of 8" won't give you the depth you need for the treads, since you will be needing a minimun of 10 1/2". As far as the glue goes, I would still use the pl200 or liquid nails, clamping them with a thousand clamps to ensure proper adhesion, since mechanical fastening is not an option.

Thank you for your response; I know my approach to this is unorthodox, and I'm just exploring the options at this time. Yes, it would be exposed, so the end appearance is a huge part of the equation. Another thought I had would be to rip my 2x8 cypress stock into 2x4's, then stack them, building the depth needed (either 10 or 12 inches) to accomodate the treads. Planed and finished, the result shouldn't be any more unsightly than a butcher block surface. Using either a core of SYP 2x12, or a layer of plywood (1/2 x 12) would require ripping some cypress as well, to add to the 12" depth, creating a joint that would also be exposed. The laminated core would be exposed top and bottom, and to cover that would equire creating yet another exposed joint. Yet another option would require assembling the ripped 2x4 edge to the 2x8 edge for each plank, then assembling two such planks, staggering the joints lengthwise. Again, the joints would be exposed in the finished product.The original plans, as noted in the earlier post, called for 2x12 beams for both carriages and treads, while other manufactured staircases are advertized as 2x10 carriages, with 2" thick treads as well. Cypress is technically a softwood, yet it is regulated in the trade as a hardwood; I'm not yet sure if using the smaller dimensions (that the Oak and Walnut staircases use) would result in the strength needed using Cypress. I suppose most of my suggestions would prove to be beyond the means of most DIY'ers, but if I had accepted that line of thought 2 years ago, my log home would still be just piles of logs in my driveway. Thank you for your thoughts, and any additional opinions are welcome as well....
Jess

I think the best glue to use for this would be a polyurethane glue specially with the carriages. You could probably get by with a good exterior wood glue like Tiebond III on the treads since they're not under the same structural demand. I like the idea of laminating the treads in the butcherblock stile. The carriages could be laminated too, without the plywood. I don't think the plywood is really going to add to the strength. If you have plenty of the cypress you could laminate three thick for the carriages. Plain them slightly to get good flat surfaces and you would end up with something actual about 4 1/2" x 11 1/2"

Thank you for your encouragement; I think the lamination of 3 pcs. would provide the beefy look I'd like for the carriages. I'll experiment on a smaller scale to see how it all works out.
Jess