Electric cooktop installation questions

[MichaelB]

Our 20 year old cooktop was not working well, so we decided to get a new one. The old one was pulled and recycled, a replacement chosen and ordered, and the granite cutout widened.

After all this, the unit we ordered cannot be delivered. We have another option, but the required cutout size is smaller. The excess cutout dimensions are 0.62 inches x 1.54 inches. The lip of the cooktop is around 1.5 inches, so it can’t go in as is, there’s not enough countertop to support the weight of cooktop plus food.

What options are recommended to fill that space? It should be relatively straightforward to attach a wood frame around the inside of the granite cutout and bring it to the manufacturer's required dimensions. The cooktop weighs around 50 lbs.

So, my questions are, is the wood frame approach sound? Would the wood be strong enough to hold the weight? Would the cooktop generate too much heat for the wood? Finally, does anyone have any other suggestions to deal with this?

Looking for another cooktop right now isn’t an option we want to consider.

 

[OldShooter]

I don't think you want wood there to become grease-soaked over time. We had a similar problem with a wall oven that was a bit over an inch smaller than the opening. We found several companies on the internet who would custom make stainless trim to fill the spaces on each side. IIRR prices were around $300. We went with a local shop, got the pieces and saved about 25%.

Re weight, it would seem that with no trim strips the cooktop weight would simply be carried into the countertop via the front and rear edges. I don't think it would be easy to attach load-bearing trim to the left and right countertop edges. It would depend on the design on the shims and the number of lateral screws tying them into the countertop. But is it a big deal? Cooktops are not that heavy. What does the cooktop installation manual say about support?

 

[RobbieB]

I would use solid aluminum bars and epoxy them to the granite.

 

[Bamaman]

Our home warranty replaced our cooktop 1 1/2 years ago, and the hole in the granite originally was too large for the new cooktop. The new GE top of the line cooktop ($1550) sat in the hole just fine, however one day the black glass separated from the rest of the cooktop. The high temperature silicone used to attach the glass didn't hold.

Although our cooktop was out of warranty, GE was good enough to replace it.

I have a full shop, and I planed wood filler strips to where the new cooktop fits snug as a rug. The wood strips were attached to the granite with a white, sticky construction adhesive. And the metal lip on the underside of the cooktop is now fully supported.

The installation actually just took me a few minutes. And GE didn't even have to pay an installer to come out.

 

[braumeister]

I would use solid aluminum bars and epoxy them to the granite.

Probably a good solution.
You should also be able to find square s/s tubes that might even be better.
If you know any local welders they ought to be able to get just the thing and cut them to size for you. Epoxying them in place should be a simple DIY job.

 

[zinger1457]

I would check with the manufacturer of the cooktop you're buying, many sell filler trim kits for exactly the problem you're having, too large of a cutout.

 

[MichaelB]

Thanks for the replies. I did check with the manufacturer, they sell a kit for smaller cooktops (30”) but not the 36” we ordered.

The trim kit might work but creates an aesthetic imbalance, so it’s a possibility but we’re looking for other options. Nonetheless I have requested info from 2 kit makers.

Aluminum or stainless steel bar is not an option I had considered, but it sounds worth considering.

I’m not sure grease is an issue. The cooktops have a gasket close to the edge of the lip, so as long as any solution we have included the lip making contact with the granite we should be fine.

 

[Ronstar]

Yep I agree the aluminum or stainless steel option should work.

 

[OldShooter]

Yep I agree the aluminum or stainless steel option should work.

Does the cooktop completely cover the spacer/trim? If not, the aluminum will be obviously a different color than the SS trim on the cooktop. Re stainless bar, drilling that will be no joy. Without a drill press it will verge on the impossible. If you do decide to drill, make sure to calculate the proper RPM cutting speed.

Re grease on wood, if the wood is exposed my concern has repeated exposure to spatter eventually soaking it with grease. It will depend on the wood finish's resistance to the hot grease spatter.

Fun stuff!

 

[RobbieB]

Square SS tubing would work just as good (or even better) than aluminum and probably be cheaper too.

Is the inch and a half on the sides? (2) 3/4 inchers would work well. The other side being 5/8", you could use half inch.

 

[OldShooter]

Square SS tubing would work just as good (or even better) than aluminum and probably be cheaper too. ...

Yes. And much easier/cheaper than SS bar stock.

OP, my go-to for this kind of thing is McMaster-Carr. They are not the cheapest but they are happy to take small orders. I didn't see a lot of square SS tubing though. Maybe your search skills are better than mine. Here's an example of channel profiles that might work: https://www.mcmaster.com/stainless-steel-channels/

McMaster is a real candy store for people who make things.

As far as material, most food-related SS products use 430 alloy. 304 is another common alloy; its color is close enough to 430 that I don't think you'd notice a difference. Iif you need to match the grain direction to the cooktop, try using auto body rubbing compound or carefully) 600 grit wet-or-dry sandpaper.

 

[scrinch]

Michael, as I understand it, the new cooktop will fit in the cutout, and the lip/flange will cover the hole all the way around, but there will be an extra 0.6" front/back and 1.54" side to side of "slop" in the cutout, where the cooktop could be moved around. Is that right? If so, then I think your idea of filling the slop with hardwood strips and supported from beneath by additional boards epoxied to the bottom of the granite is a good idea. Or you could run the bottom supports all the way to the front and back of the cabinet and support them with cleats on the inside of the cabinet.

As far as heat goes, countertops are often made of solid wood (butcher block), particle board (formica), or plywood (beneath your granite). Cooktops are designed to reside adjacent to the wood cutouts in these wood countertops. So no worries about putting wood filler/support strips in yours.

 

[RobbieB]

You know, that's right!

Just because the counter happens to be granite, it could as well be wood.

Yeah Baby! Make your life easy and just epoxy on some solid oak -

 

[Scrapr]

Maybe too late now....but

Our house built in 1994 the granite guy cut out the hole too large for the cooktop.Template was on the table next to the counter. I fired him. Our builder suggested cutting a piece of granite from the scrap & epoxy it in. We did & it worked fine. But...that strip of epoxy bugged me for 23 years everytime I was in the kitchen

 

[Bamaman]

I checked my old GE stovetop, and from the body of the cooktop out to the edge of the glass is 1 1/2 inches.

So if my hole is 1.5 inches larger in width or length, it could be centered and have .75 inches around it--plenty enough room to glue a spacer. I used 1 1/2 inch birch wood planed down--and my granite's about 1.5 inches thick.

 

[MichaelB]

Our cooktop was installed yesterday, so I thought I’d update. Robert Burns said it best “ The best laid schemes o’ mice an’ men. Gang aft a-gley”.
The best laid plans of mice and men often go awry.

The spacer trim didn’t work because all the ones I saw were for smaller (30”) and lighter (<40 lbs) units than the one we bought. The steel or aluminum bars idea was also discarded because the cooktop is smaller than indicated in the spec sheet, and part of the cutout filler material is exposed and visible. These were both good suggestions and my preferred options.

The left us with only one option, which was to look for a piece of granite to fill the cutout along one side. We have a handyman who got the granite and glued it with epoxy, with a couple of wood strips along the sides. The colors are mismatched, the filler is lighter, but it works.

The mismatched granite is along the back, not easily seen, but it is visible, so DW is looking for some permanent markers to darken it.

This is the second major appliance we have had installed in the kitchen and I can see now why people say it’s easier just to remodel the kitchen instead of trying to make new appliances fit existing spaces.

 

[Bamaman]

Glad you worked out your issues. My problem was with the granite installer--rather than the appliances.

My cooktop was replaced by GE even though it was out of warranty--$1150. The Kitchenaid dishwasher would be almost $1000 and the double convection ovens $4,000. Makes a $2,250 side by side refrigerator look cheap in comparison. My house is 14 years old, and that's when problems arise. Heck, we do most cooktop cooking in an electric skillet and most oven work in a air fryer anyway.