The Perfect Seam, Part I

December 6, 2005

It’s the dreaded question. The lump in the stomach forms as the customer calls NASA and points the Hubble space telescope at your hard work.
We built our company on doing the best seam work possible. It’s become our hallmark, and we work hard at maintaining our rep.
Like everything in this business, there are many different ways to do things. What may be perfect to us could be a “over-the-top, the client is not paying enough for a perfect seam” situation to other shops. (I confess: I feel that way at times myself.)
What is a perfect seam? It’s hard to describe, but I know one when I see one (or don’t). In a perfect world, a seam in granite would be one that you can’t see or feel. Using some of these methods, you can get really close to, if not hit the mark with, perfect seams.
I can hear some of the grumbling out there. “Why do all the extra work for perfect seams when we’ve had no problems with the way we’re doing it.” “I’ve never top-polished a seam and always gotten paid.” “Why go through that trouble?”
In one very nice, simple word: MONEY!
After we started building perfect seams, referrals went up and we started doing more and more higher-end projects. People that have the money to pay for perfection usually hang out with other people with money; they refer folks that they hang out with, and you’re now dealing with some nice (and profitable) word-of-mouth.
In the pursuit of a perfect seam, the first step is setting a realistic expectation with the client. If the stone or the situation doesn’t lend itself to a perfect seam, don’t sell it that way.
We look at a drawing and try to figure out ideal seam placement before we choose a color. If the veins and movement of the stone doesn’t work with the shape of the kitchen, we’ll steer the client away from that choice. The client always seems to agree with you when you say, “This stone will give you really weird seams because ….”
Set yourself up for success before you cut the stone. If you’re doing Uba Tuba or some other oatmeal- ooking stuff, you should be good to go. Start selling Typhoon Green, and you had better have a good idea of where the seams are going to hit before you sell that $12,000 countertop.
So, you’ve sold the color and made the templates. What now?
Ah. – the sawyer. This is where the art truly begins.
When working with exotic stone or ones with movement, we’ll lay one slab flat on the saw and put the others on A-frames. We try to figure out exactly where the parts will fit on the slab; we often move a seam on the template a few inches to the left or right to get features to line up.
Once you’ve made the first seam cut, try to save the falloff from the opposite side of the cut. We place this on the template to aid in lining up the veins and colors on the next seam cut.
As a rule, if we can’t make a vein or feature line up perfectly, we will butterfly the seam. Done correctly, this detail can turn your seam into an amazing detail.
After the tops are cut, we stick ‘em in the CNC. This is where the rubber hits the road. There are two major advantages to taking the time to perform this step on a CNC:
• A cut made by a saw is not perfectly straight. The CNC will make the edges straight to .0003 of an inch. (That’s about how wide the seam is)
• As the CNC straightens the cut, it also grinds back the seam and removes the little chips as it goes.
The end result are very tight, chip-free seams.
While the stone is still in the shop, we use a grinder with a turbo blade or cup wheel and back-bevel the seam about 10°, and we leave the top of the seam untouched. This cut allows us to insert adhesive from below; the seam will be much too tight to pack glue from the top.
At the jobsite, we set the tops and getting them flat is sooo critical. Once we achieve that flat level, we use a paralign clamp (in our case, the Gorilla Grip from Monument Toolworks). This is a must-have for granite installers; have you ever put a top together and had it perfect in the front, perfect in the back and a bow in the middle? This will bend the stone flat. This tool is expensive and worth every penny; it runs on a electric vacuum pump.
Once the paralign has been turned, holding the seam exactly where we want it – well, we do an interesting little tap dance. We lock the first inch, one inch in the center and one inch in the back, with polyester. Then we use a penetrating adhesive (our choice is Chemical Concepts CA) from above. This will all fire off in about five to ten minutes. This is where the clamp is so awesome; it will hold it for as long as needed with that electric pump.
The remaining portion of the seam (a 10” section in the front and rear) gets packed with setting epoxy (and we use TouchStone T-2000). The polyester and penetrating adhesive holds the top while you do your work and top polish. The epoxy holds the seam together for life. If we have to seam over a dishwasher or on a raised eating bar, we’ll use the same epoxy and adhere a 2” x 6” x 1/8th steel plate toward the front and middle.
At this point, we scrape down the seam and top-polish it. Imagine a seam that is no wider than a human hair and can’t be felt! It is doable, but’s a lot of work.
Next month’s article will cover top-polishing seams. This is an interesting task to master; once you get the hang of it, you’ll be able to knock out a 24” seam in 15 minutes or less. I promise the extra work pays off in the long run.
If you would have specific questions about seams go to www.stoneadvice.com. If you have a question, post it in the forum, and our panel of moderators will try to answer your query.
‘Til next time… Mark Lauzon, stonecutter.