A stable table top starts with the right knowledge.
The construction of a wood restaurant table is harder that it looks. While it is simply a glued up block of wood, it must be manufactured in a very specific way to create a durable surface. The hospitality industry is notorious for being hard on wood tables, so extra effort must be considered in all aspects of construction, from milling and board selection to the finish. Here are some of the aspects that go into the construction of a wood restaurant table.
Kiln Drying
In order to make wood stable enough for furniture, it must first be kiln dried. The main purpose of kiln drying lumber is to remove excess moisture so the wood stops shrinking when it is dry. Other advantages of drying your lumber in a kiln is to eliminate any bugs that may be living in the wood and to solidify any pitch that may be present. Once the lumber is kiln dried to 8% moisture content, it is considered to be furniture grade for a tabletop.
Grading the wood
Choosing the right grade of wood for a restaurant table is also a very important aspect of the construction. Different species of wood have different grades and you need to know the difference in order to select the boards that will perform best for your application. Flat grain and vertical grain perform differently. There is much more expansion and contraction in flat cut lumber while vertical grain tends to be more stable, but much a less interesting looking grain pattern. Selecting boards that are free of center strikes is another consideration to think about when choosing wood for a restaurant table top. The grade we use is called FOHC, or Free Of Heart Center. The heart of the tree is usually prone to cracking and is not suitable.
Straightening edges- Sawing
Once the wood has been kiln dried to a furniture grade, the individual boards need to be straightened in preparation for molding. This edge work is done with two machines; a gang rip saw and a molder. The Gang rip saw is like a very heavy duty table saw, but has multiple blades. These blades can be set a specific distance from each other. When a crooked board is put through this machine, the parallel blades straighten out the board. This process makes it easier for the second machine to process.
Straightening edges- Molding
A molder is a high-tech version of a planer, but it has multiple heads on all sides. The purpose of putting the wood through this machine is to create four edges that are perfectly square and parallel with a very fine cut to them. The wood that goes through the molder is slightly rough as it goes in and perfect when it comes out. We use very precise machines to mill the lumber because it makes for a an easier glue up and a more stable table.
Rotating the grain direction
It is said that it takes 10,000 hours to become an expert at anything. Only after that amount of time will you have seen all of the issues that can occur and know how to handle them. Some of the things we learned very early on the way to becoming expert table makers is that you must alternate the grain direction of each plank in a table. This is especially critical when using flat grain lumber. The alternating grain pattern counteracts any seasonal movement from becoming pronounced and helps with the dimensional stability of the table.
Dry assembly
Dry-assembling the planks allows our craftsman to make sure the grain orientation is correct, and that the table looks good before it is assembled. Think of dry assembly like a preview. You can correct aesthetic elements that we might find distracting, which creates a more balanced look. The loose boards are easily transferred to the clamps for gluing in the exact same order. This helps with eliminating mistakes and costly rework.
Glue
The most widely acceptable glue used in the construction of wood tables is Polyvinyl Acetate, or PVA for short. PVA glue is a food contact friendly adhesive that forms a tight bond between two pieces of wood. This type of glue has no added formaldehyde so it complies with CARB2 standards. PVA comes in a variety of types, from fast setting glue that you can handle 30 minutes after application, to types that have long open times for elaborate construction projects. These long open time glues are typically used when the weather is hot and you don’t want the glue to setup before you bond the two pieces of wood together.
Professional Clamping
Successful glue-up starts with a good clamping system. You want even pressure across the entire length of the boards. You also want the right amount of pressure to make sure the glue is perfectly in contact with both sides of the wood you are gluing. Too much pressure and you will squeeze all the glue out, too little and your table will fall apart. There are many ways to apply pressure to wood during the gluing phase. We use a machine called a Taylor Carrier Clamp. This machine was made for edge-gluing parts together.
Pipe Clamps
There are other ways to achieve the same goal; pipe clamps and bar clamps are the most common. All clamping systems do the same thing; put pressure on the edges of wood to bring them close enough so the wood glue has time to set up. The most high tech version of a gluing machine uses hydraulic pressure to clamp the wood, and microwaves to cure the glue in seconds. This machine is called an RF (Radio Frequency) press. It is used in high volume shops for repeated parts that are the exactly the same size.
Planing/Sanding
A large sanding machine is typically used to clean up the tabletops once the glue is cured. We use a combination planer-sander that takes off more material so that we have fewer passes through the machine. If you only have a small sander, it will take more labor to flatten a tabletop and get rid of all the glue squeeze-out left over from the clamping process. To flatten a tabletop, feed one side of the table through your sander multiple times until you see no more glue squeeze out. Once you have a perfectly flat back, you flip the table over and start sanding the face of the table. You are trying to eliminate glue squeeze-out and make all of the tables a uniform thickness. This ensures that all of the tables from a batch are the same height. The final sanding of the table uses a fine grit so the true depth of the grain is revealed.
Edge work
Cutting the table to final dimension is done with a large sliding table saw or a panel saw. Both of these types of machines excel at this type of cutting and are very accurate. Once the tables are cut to the customer’s dimensions, our craftsman adds the final edge work detail to the tables. This process includes using a hand operated sander to smooth out the edge grain and a hand-held router to ease all of the sharp edges.
Finishing
After all of the hand work is done, the table is ready to go to the spray booth for multiple layers of conversion varnish. Our conversion varnish has been tested to withstand Ecolab cleaners along with a host of other corrosive things like bleach rags, alcohol, citrus, mustard and wine. For a detailed explanation of why conversion varnish is the best finish for restaurant grade table tops, read our article on Finishing Wood Restaurant Tables.
One critical aspect of finishing any tabletop is making sure the underside of the table is finished with the same number of coats as the top. If one side has more finish than the other, then the ambient moisture will seep into one side of the table more than the other and cause the table to slightly warp.
Watch the Video!
If you are still curious about how we make our tabletops and want to see our shop, check out this video we made especially for you!
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source https://viridianwood.com/wood-table-top-construction/
The first step is making sure you protect your wood tabletop during the installation process. Moving blankets are ideal for this because they are inexpensive, thick and you won’t worry about laying them on the floor. Cardboard is an option as well; anything that is soft and thick enough to protect your tables from scratches or dents. Make sure the blanket or cardboard is spread wide enough to accommodate the entire length and width of the you are about to install. Place the wood table face down on the blanket, with the underside exposed for the installation of the base.
The next step is to take your pencil and a straight edge and lightly draw a line from corner-to-corner, creating an “X”. These lines will mark the exact center of the table and will allow you to perfectly center the base onto the tabletop. Communal base installation is discussed later on in this article.
To determine the depth to pre-drill the table, measure the thickness of the wood table and subtract ¼” inch. Place a piece of blue tape around the shaft of the drill bit at that point. 
Once you have determined the center of the table, place the assembled table base upside down onto the underside of the table, as if the assembled table were sitting upside down. Rotate the screw holes in the support arms of the base to align with the reference lines you penciled in.
Using your pencil, mark the locations of the holes and remove the base to the side. Drill the marks you just made. Make sure not to go past the blue tape on your drill bit! Sweep away any saw dust and place the base back onto the underside of the table. 
Align the holes with the base and insert screws. Tighten them up making sure not to over torque them. (Pro Tip: The screws only need to be in there firmly, not too tight. You want the table to be able to move with the seasons as it expands and contracts with the humidity).
each claiming to be the most durable; most of them are indecipherable from each other once cured and there are many good choices. Conversion varnish is chemically cured, meaning that a second chemical called a catalyzer or hardener is added to the mixture to help cure the finish. The catalyzer sets off a slow chemical reaction that starts to cross-link or cure the solid materials in the finish to make it more durable. Conversion Varnish is typically 60% solids, while the remaining 40% is a solvent that is used to thin the solution enough for spraying. There are several ways to apply this type of finish, but it is typically applied with a spray gun in a spray booth. Spraying the finish gives a very even appearance and lets you control the build levels of the finish, allowing you to apply just the right amount. It is possible to use a brush to apply this type of finish, but it is not recommended because it can leave brush marks. There is no doubt that Conversion Varnish is the most durable finish for restaurant tables. The type of conversion varnish that Viridian Reclaimed Wood uses has been tested for compatibility with Ecolab’s most common cleaning agents that are used in restaurants. We’ve tested this finish against common bleach rags, alcohol, citrus, wine, vinegar, ammonia, mustard, and ketchup. We have also submitted samples of our tabletops for abrasion testing, all of which easily passed.
light! The finish is rolled or sprayed onto the surface of the wood tabletop and is passed under a series of very bright lights that produce various wavelengths of UV light. When the finish is exposed to these intense lights, it immediately transforms from a liquid into a hard solid. You may have seen this technology before in nail salons, some types of Gel nail polishes are cured with UV lights. UV finish is a special solution containing proprietary ingredients, but here are the basics. Instead of having solvents in a mixture like in a conversion varnish, UV contains 100% solids. This means that there is nothing to evaporate. This mixture of solid materials is combined with a photo initiator that reacts with the lights to cure the finish. One of the advantages to this type of finish is that it has no VOC’s, so it is very environmentally friendly. It is also a very hard finish that is resistant to many chemicals and abrasion. The down-side to a UV finish is that it requires expensive specialized machinery to apply.
varnish, except it’s less resistant to the cleaning agents commonly used in restaurants. Epoxy is a two-part mixture that when mixed, sets off a chemical reaction that starts to cure the two parts together. The benefit of an epoxy finish is that it can seep into the smallest of cracks and voids, filling them up with the finish. When finishing reclaimed wood tables for restaurants, it is typical to make up a thin batch of epoxy and brush it on a rustic table top to help seal the small cracks commonly found in materials like barn wood. The last thing a restaurateur wants is a table that has not been sealed that can collect food and debris, creating an unsanitary condition. Once this thin epoxy layer is cured, a traditional conversion varnish can be sprayed on top to help create a chemical resistant finish that will be more durable. Epoxy creates a thick, durable top coat for tables with a rustic surface. The down-sides of such a thick finish are that it is costly, increases lead times for production and it can’t be repaired easily on-site. Another drawback to epoxy is that it can yellow over time.
restaurant tabletop. The reason the polyurethane finish fails so quickly is that the cleaning agents typically used are very harsh and break down this type of finish. Polyurethane was developed for flooring, not tabletops. Bleach and common Ecolab sanitizers will eat through this type of finish in a relatively short time, leaving your tabletops tacky to the touch; not a good first impression to your customers. Unfortunately, there is little to be done once the finish gets tacky. The best option is sand off the old finish and try to recoat the tops with something more durable.
good job at keeping moisture away from the surface of the wood. Obviously, since this finish is so low on the list, we would never recommend it for a high volume commercial table top coat. Wax finishes need to be reapplied frequently to keep their luster and the level of protection. One benefit of a wax finish is that it can easily be repaired, just by buffing in more wax onto the surface. One of the biggest drawbacks, other than the durability, is that once you use a wax finish, you can never use another type of finish on top. Wax is a release agent, so no other finishes will stick.
and allowed to dry for a day or so before re-coating. Oils are very easy to apply. They really bring out the grain of the wood and look beautiful. The downside is that they offer little to no protection from moisture or chemicals for the wood. We wouldn’t recommend an oil finish for an indoor restaurant application unless you are committed to re-oiling the tops regularly (possibly as frequently as weekly). We do, however recommend high quality oil finishes for outdoor restaurant tables. Hard film finishes like Conversion Varnish are not suitable for exterior tables that are exposed to the elements. They must be coated with a “repairable” finish like oil so that every year the tables can be refreshed with a new coat. Our favorite exterior oil finish for wood tables is 
