I am looking for guidance as I don't want to lose my shirt on this job, which is a bit intemidating. I am going to glue up a 60"X36"X4" endgrain butcher block counter top similar to the one pictured. I have done 100 or so cutting boards like this using Titebond III, which is a PVA glue with a soft glue line. What is everyone else using for this type of glue up. Epoxy seams like a night mare because of the long clamp time and how many small glue ups it will take to make this whole panel. Urea Formeldahide seams like a good choice, but the glue line would be a light tan color and would not look good admidst the feald of dark walnut endgrain. I look forward to learning about your process.

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Unibond a UF type adhesive that has two colours of catalyst powder available. Have a look at Vacuum Pressing Systems website. It is strong and waterproof with a long open time.
Titebond 3 or 2 will expand if you use an oil finish on the block leaving you ridges on the glue lines.
Epoxy will work and you can find a formulation that cures at the rate you want. It will saturate and darken any area it is absorbed so test if it is visible or unsightly when you apply finish to a sample.
There is polyurethane, Gorilla, glue with a short open time. The drawback is the joints must be tight. Any gap and the glue foams and has no strength at all.
You may or may not care since so little adhesive will in food contact but have a look if any adhesives are considered food safe.
I'm not a fan of UF glue after working with it in hot pressing (my throat constructs and eyes are red for hours after) so I would use epoxy or PU

Get a Universal Tint for the plastic resin glue to darken it. The rigid glue line will not swell like TB II or III. Long open time. Great bonding. B
But, you must have everything - wood, water, room, clamps, etc - over 70 degrees, or expect failure.

Tom, Thank you for the advice. I think I am going to do a practice gule up with unibond and some medium cure time epoxy and see how they come out.

David, thank you as well for the advice. I'm going to test the two and see how it come out. No worries with the temp not being high enough. I'm in South Texas. My normal worry with epoxy is that it is getting to hot and needs it's own fan.

The folks at Spectrum Adhesives were super helpful. They published this document which was a helpful intro to the diffrent glueing processes. It may be helpful if it was sticked here on the adhesive fourm.

Click the link below to download the file included with this post.

CP_Adhesives_Better_Gluing_Guide.pdf

Wilsonart makes a PVA that has a very rigid glue line. When it dries it sands like wood. Not like gun. It is as close to the Urea Formaldehyde 2 part glue as you can get. The regular assembly is WA 30
The Water proof or resistant ( depending on which testing method you follow) is WA 3135-OV.

unibond is a great choice... and as david said, you can tint it easily with a universal pigment, or transtint, and best of all, you can use their bleed blocker powder and dial in the thickness and viscosity of the adhesive. stir it thoroughly with a small mechanical paddle/whip mounted to a drill - stir it, wait a few minutes, and stir it again to ensure all of the salts are dissolved. all-in-all, it's an excellent, waterproof and creep-proof product. as stated, keep it warm to cure (i cover the work with a heating blanket). oh, and if you keep the liquid in the fridge, it dramatically increases the shelf life.