Repair Plan Mends Cooktop Cracks

While surveys show that the majority of homeowners who have purchased solid surface kitchen countertops are delighted with their decision, a few consumers do experience problems. Responding to their complaints effectively is a way to ensure the continuing high reputation that solid surface materials enjoy.

One of the most difficult problems that needs to be addressed is countertop cracking adjacent to a cooktop or a range. Many complaints of cooktop cracks I've witnessed are repeat complaints in other words, a previous repair attempt has been unsuccessful.

The most important way to prevent this sort of problem is to follow the manufacturer's recommendations for machining and preparing a cooktop cutout. Work from a checklist, and be sure that every procedure has been carried out properly.

Even with good fabrication and installation techniques, however, failures can still happen. It may not be possible to identify the reason for a given failure with absolute certainty, but patterns do emerge.

Heat is the most important factor responsible for this problem, since cracks at cooktop cutouts are far more common than those at sink cutouts. Heavy cooktops also tend to cause problems more often than lighter cooktops, as do cooktops with narrow flanges. Cooktops with built-in downdraft fans also cause more problems. Cooking styles such as prolonged, high-heat cooking, deep-fat frying, candymaking and canning also increase risk, as does the use of high BTU "power burners" and cooking without a ventilation fan.

The shortcoming of conventional repair techniques is that, in many cases, the underlying cause of the problem is not addressed. In order to have a high success rate in repairing cooktop cracks, the repair procedure must accomplish two things: It must effectively isolate the countertop material from the heat source, and it must remove the weight of the appliance and items being cooked from the countertop.

The right repair
The most effective repair procedure involves fabrication and installation of a custom stainless steel ring or collar that surrounds the appliance. This stainless steel surround allows for the cutout in the countertop to be enlarged significantly, and for a plywood support structure to be fabricated and installed, which takes the weight of the appliance off the cooktop.

Consumers will, of course, be concerned about the appearance of this stainless steel collar. It's essential to present this repair procedure tactfully, explaining that the item will be custom fabricated to match the specific cooktop in question, and will appear to be part of the original cooktop. If the cooktop has a brushed stainless finish, that's how the collar should be finished as well. The collar can also be powder-coated to match any standard appliance color.

A properly sized cooktop collar will extend 1/2" past the flange of the cooktop on all four sides. The visible outside corner radius will complement the existing outside corner radius of the appliance. For example, if the existing cooktop has a 1/4" corner radius, I have the collar fabricated with a 3/4" corner radius. Since the collar extends 1/2" past, a radius 1/2" larger will look very natural and compatible.

The cooktop collar must be measured carefully, with cutout dimensions being large enough to accommodate the cooktop. Check for any irregularities or protrusions on the cooktop body, such as screws, rivets or flanges, and be sure to allow for them.

The outside dimensions should be 1" larger in both directions than the overall dimensions of the cooktop. This will allow for 1/2" of the stainless steel collar to show on all four sides. After the stainless steel cooktop collar has been obtained, make a matching collar out of good quality plywood the same thickness as the countertop material, usually 1/2". The cutout in the plywood will be the same size as with the stainless collar, but the overall dimensions will be 1/4" to 3/8" less, to allow the stainless steel to overlap the plywood by at least 1/8" on all four sides. Neatly wrap this plywood collar with aluminum tape.'

When the repair begins, disconnect and remove the cooktop and place the plywood collar on the countertop surface, aligned with the existing cutout. Draw a pencil line around the plywood collar. Using a router, enlarge the cooktop cutout in the countertop slightly past this pencil line. At this point, your plywood collar should fit loosely into the opening.

Now, repair the crack in the countertop, and reinforce the repair wherever possible with a second layer of solid surface material bonded beneath. Trim the finished repair back flush with the enlarged cutout edge, and sand all edges of the cutout until perfectly smooth. Round over the top and bottom edges, and be sure that all irregularities have been eliminated.'

Next, fabricate and install a plywood support frame, connected structurally to the cabinet and possibly the wall instead of the countertop. The exact configuration of this support frame will vary depending on jobsite conditions, but it must be stable and sturdy, and its top surface must be flush with the underside of the countertop material.

Place the plywood collar into the opening. It should sit flush with the countertop surface. Using thin shims as needed between the support frame and the plywood collar, ensure that the top surface of the plywood collar sits just slightly higher than the countertop surface about 1/32" is right. Strips of plastic laminate work well as shims. Finish the inside of the opening with aluminum tape or insulating tape in accordance with the solid surface manufacturer's recommendations.

Place the stainless steel collar on top of the plywood collar, and reinstall the cooktop.'
If the repair has been done properly, there will be a barely visible gap between the stainless steel collar and the solid surface material. This air gap is your assurance that heat transfer has been dramatically reduced and that stress due to the weight of the cooktop bearing on the countertop has been eliminated.

Some consumers may prefer a bead of caulk between the stainless steel collar and the countertop. Others may want to be able to lift the assembly for cleaning. Either technique is fine.

Stainless steel collars can be ordered through my Web site, www.heaphy.com. At this site, you'll also find a comprehensive directory of solid surface industry Web sites, and copies of many of my past columns.

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