Buddy replied,

"One way to grout the seams is to make your own sanded caulk. We find a flexible caulk is a little better than a cement grout because the concrete slabs seem to expand and contract in the sun or over a dishwasher so the caulk will flex with the movement."

We use a white Phenoseal Vinyl Caulk  and color it using the same colorant we used in making the countertop. Pump out the fresh white tube(s) into a bucket and mix in a little fine #60 sand and the BR Ultra Dry Pigment to achieve the color you need. This takes a little work to get just the right color and then put it back into a new clean caulking tube. Label it and leave on the job site for future use. Most times the caulk will shrink and crack within the first week or two so expect to go back and fill the cracks with more caulk.
One of these days we will have BR color caulking tubes on our web store for your seaming pleasure. In the meantime, pastry bags work as well or a putty knife and  sponge.

4.  Work Table Designs?

Robert Aurner wrote,

"... I have been reading on some other sites about using steel for the tops and a torsion box under that with a box steel frame.  Anyone have ideas or plans they would care to share? 

 
Steve Millard replied,Bottom of Form

 

 

 

Steve Millard replied, "

 

I have four tables I made from 2x2 angle iron. They each have 6 adjustable casters on them. The tops are melamine that just rest on the table frame. I do not fasten the melamine to the tables for several reasons, 1- makes them easy to replace, 2- they can be flipped over and use the other side, 3-they vibrate better, and 4- it makes it easier to de-mold the countertops. I never put holes in the melamine because that ruins it, and I am able to get dozens of countertops from 1 sheet of melamine. I can roll the tables around as needed and I can join tables for longer or wider, or irregular shaped projects. The  picture [above] shows 2 of the tables in the background.

 

Sean Albright adds,

" I built a couple of casting tables using the torsion box technique I learned from projects on the wood whisperer (inspired originally by David Marks). Here are a couple of links: 

Torsion Box , Assembly
A typical torsion box assembly table is made of mdf but you can make it out of almost anything (I made mine of dirt cheap OSB, doubled up 2x4s for legs and skinned the top with hardboard). The great thing about a torsion box is first that you can make it dead flat and with minimal tools that you probably already have (table saw, brad nailer or screw gun, and glue). It's incredibly strong (airplane wing strong) yet light - no need to add to the weight you already need to roll around with your counters. You can beat the heck out of it knowing that it's easy and cheap to replace if you ever need to. And you can make it any dimension you want to meet your needs. I could go on...

I'm incredibly happy with mine and can't stress enough the physics behind the design. As soon as I was done building it I spanned it across 2 saw horses, 1 at each very end (8') and jumped up and down on the middle of it (I'm a modest 200lbs). It didn't have the slightest hint of give. Give it a shot!