Heat Cracking

[lensmith]

Today I took a look at two failures, both of which started at a seam. In both cases, the homeowners were using cooking devices (one was a deep fryer, the other some sort of wok device.) One of the cracks started at the backsplash, and started running toward the front, stopping about half way through. The seam had a seam support underneath, and the split broke the seam support right in half! Kind of amazing, the power of hot and cold.

Both homeowners at first admitted to using the cooking devices, then both denied it later when they learned it could void their warranty.

Here's my question: We can't just tell homeowners "you can't use those things if you have a solid surface top," so does anyone have a suggestion for things to suggest to homeowners to dissipate the heat?

[John Turner]

Can you provide a customer information and sign off sheet at completion of project. Warranty sign up and info is on websites. Most mfgs have discontinued with information booklets.

If sales through GC or K&B dealer info is tuf to get to the end user. Can you make it part of the deal? You get photocopy with check. They have to have a vested interest.

homeowners must use solid heat shield with air space underneath. Fabricator to provide? we do.

[lensmith]

John,

What kind of solid heat shield?

Len

[chrisg]

I think John is talking about a Hot plate with rubber feet that can be made from a scrap pc (we hate to say scrap, how about odd size pc) of solid surface material.The rubber feet provide an air space between the deck which helps disapate the heat.

[John Turner]

Len, chrisg is correct. a solid surface piece with bumper feet. I also suggest to the client a cutting board or anything like it , with little feet.

[jkbrand]

The seam had a seam support underneath, and the split broke the seam support right in half! Kind of amazing, the power of hot and cold.


I teach fabrication classes in Denver, and at the end of the day when time permits, we take a propane torch to different seams. We direct the heat to the side (a few inches away), and in short order, the seam separates. The sound is like discharging a .22 rifle.

We also do the same test on a seam that's been blocked underneath. The result is the same: the seam separates and sometimes the block cracks.

The demo serves to remind new fabricators they MUST communicate with the homeowner the danger of heat-generating devices (crock pots and electric fry pans). The tops themselves will handle more heat than any seaming compound, but that's not an endorsement to simply keep heat-generating appliances away from seams.....

We always provide a cutting board with vinyl feet attached to isolate the board from the deck. Customers are reminded to use the cutting board under their crock pots and electric fry pans.

Oh, and something you can try for yourself what we often do in the class: take a cutting-board size piece of SS and heat it up with a propane torch. It can be heated so hot you can't hold it in your hands. Why doesn't it break? Because the whole piece is uniformly heated (same as with thermoforming). Cracks (except at inside corners, where stresses are wholly different) from heat rarely occur where the temps are hottest; rather, the cracks occur at the interface where hot meets cold.

Jeff Brand

[John C]

I too, have seen seams fail and crack all the way through the reinforcement strap. So far it has always been in situations when the reinforcement strap did not extend all the way back to the edge of the deck. I think that this allowed the deck seam to start cracking at the edge first, once that hapened it was real easy for the reinforcement to crack at the same seam line (stress riser). I think that it is important to make sure that the reinforcement strap is flush with the back edge of the deck and that it runs all the way forward to the back side of the edge Build up. If it happens to be an on site seam location, then it is important that the back side of the edge build up is flush so that the reinforcement strap will make glue contact with both sides of the site seam.

My 2cents.
John C

[KarlC]

One of the first things that we do is try and do is educate the customer as to why heat caused a crack in the counter. This is NOT just a Solid Surface problem, we have seen heat (and cold) from house hold items crack Tile, Marble, Granite, Solid Surface and other products. It can be a thermal shock or a slow expansion that can cause the crack. Most off the shelf cutting boards or hot plates will help protect the counter, and as they are not a large slap that is glued down they can shrink and expand freely. As we all know each product type has it