Replacing an existing gas hob with an induction hob in a quartz worktop

DoctorJools · Post by **DoctorJools** » Mon Apr 06, 2020 12:46 pm

I'm thinking about replacing our ugly, difficult-to-clean, inefficient gas hob with a shiny, new, sleek induction one.

The good news is that the hole that's been cut for the gas hob is big enough for the induction hob. The bad news is … that the hole that's been cut for the gas hob is slightly too big for the induction hob!

The hole is 916mm x 500mm and the hobs we're looking at specify an installation aperture of 880mm x 490mm - so that's 36mm too much in one direction and 10mm too much in the other.

I'm assuming that the hole needs to be pretty much as specified as the hob and the pans we'll be putting on it will need adequate support. I did find another post on this excellent site about this sort of predicament, but it was a couple of years old and I just had a few questions that I though the clever people on here might know the answers to.

I initially though of packing the existing aperture with a couple of lengths of stainless steel bar (one thickness 36mm and the other 10mm), held in with epoxy. (Not screwed in as I've read quartz is v. difficult to drill and prone to splitting if you rawlplug it.) That way, I could reduce the dimensions of the aperture to the specified 880mm x 490mm.

Then I wondered if hard wood would do instead; more likely to take glue well (?) and easier to file if corners etc. need rounding.

Next in my train of random ideas was to get a stainless steel frame to glue ON the worktop. The cutout would be the required size (880mm x 490mm) and the external size would be big enough to more than cover the existing hole. The benefits of this approach would be that the gluing aspect wouldn't be as critical as the glue would just be holding the frame from slipping sideways - not actually supporting the weight of the hob and pans. Also, the frame would (possibly) "look nice" - as it would just be another bit of shininess around the already shiny hob.

But getting a frame cut to size looked a bit tricky, so I went back to where I started and began to wonder whether I could instead use several pieces of stainless bar in some way, laid on top of the worktop.

Then I thought that I was in danger of proposing something completely daft and wondered if somebody who actually knew what they were talking about could make some sane suggestions!

So, what do you think?

Rorschach · Post by **Rorschach** » Mon Apr 06, 2020 2:16 pm

What is underneath the hole?

DoctorJools · Post by **DoctorJools** » Mon Apr 06, 2020 3:16 pm

Rorschach wrote: ↑Mon Apr 06, 2020 2:16 pm What is underneath the hole?

A drawer. The distance from the top of the side of the drawer to the top of the work surface is 6cm.

Rorschach · Post by **Rorschach** » Mon Apr 06, 2020 3:41 pm

Ok. If it were me (assuming possible) I would add some battens going across under the workshop, glued to the underside of the quartz and screwed into the sides of the carcass. I would make these battens as large as possible to get maximum glue surface and as many screws in as I could.
Once they are in I would then add the strips you mention to bring the opening closer to the specified size. I would make these out of hardwood so they are nice and strong. I don't think you need to worry about heat resistance and use something expensive like stainless steel since the hob could be fitted into a chipboard worktop normally.

dewaltdisney · Post by **dewaltdisney** » Mon Apr 06, 2020 4:09 pm

This would be a simple job for a metal fabricator. They could make up a metal rectangular insert that would make up the difference between the hole and the hob. A polished finish would make it neat and look part of the appliance. Problem is with everyone on lockdown you cannot get a speedy result.

DWD

DoctorJools · Post by **DoctorJools** » Mon Apr 06, 2020 9:07 pm

Thanks very much Rorschach and dewaltdisney - some good ideas to have a think about. (Speedy result not needed at this stage - we haven't even looked at an induction hob in real life yet! Waiting for the shops to open again.)

Chippo1 · Post by **Chippo1** » Tue Apr 07, 2020 9:15 am

How about a stainless steel patriss all around , basically a rectangle of say 1.5 annealed chemically polished sheet with hole for the new hob, sounds expensive , but find a local sheet metal company and they could laser cut this in minutes most likely for bear tokens, then glue this to the top and site hob in it . Sort of thing a lift industry fabricator would do easily.

ayjay · Post by **ayjay** » Tue Apr 07, 2020 9:23 am

Chippo1 wrote: ↑Tue Apr 07, 2020 9:15 am for bear tokens,

Polar, or Grizzly?

DoctorJools · Post by **DoctorJools** » Tue Apr 07, 2020 11:50 am

Chippo1 wrote: ↑Tue Apr 07, 2020 9:15 am How about a stainless steel patriss all around , basically a rectangle of say 1.5 annealed chemically polished sheet with hole for the new hob, sounds expensive , but find a local sheet metal company and they could laser cut this in minutes most likely for bear tokens, then glue this to the top and site hob in it . Sort of thing a lift industry fabricator would do easily.

Thanks - I think that's what I was suggesting with my "stainless steel frame to glue ON the worktop" but I was a bit put off that idea when I did some Googling and found it looked quite expensive / difficult. I'm not sure we have a local sheet metal company here in Oxford - could you recommend somewhere?

Chippo1 · Post by **Chippo1** » Tue Apr 07, 2020 11:59 am

Tricky one, Dr Jools. The ones I know mainly are based in east and south London. But you could look up a company called ELSFAB in barking and mention my name, there will howls of derision at first but Steve Richards will give you a decent price.

ayjay · Post by **ayjay** » Tue Apr 07, 2020 12:17 pm

https://www.google.co.uk/maps/search/me ... 0209?hl=en

DoctorJools · Post by **DoctorJools** » Tue Apr 07, 2020 5:02 pm

ayjay wrote: ↑Tue Apr 07, 2020 12:17 pm <span class="skimlinks-unlinked">---3s0x48713380adc41faf:0xc820dba8cb547402!4m2!1d-1.2577263!2d51.7520209?hl=en</span>

Oh … erm … those ones! Ta.

fin · Post by **fin** » Tue Apr 07, 2020 5:57 pm

would you not be better off seeing if there is any other makes that have a larger required opening?

fin · Post by **fin** » Tue Apr 07, 2020 5:58 pm

although granted that certainly on standard 600 hobs they all seem to be basivally the same sized openings

DoctorJools · Post by **DoctorJools** » Tue Apr 07, 2020 6:44 pm

fin wrote: ↑Tue Apr 07, 2020 5:58 pm although granted that certainly on standard 600 hobs they all seem to be basivally the same sized openings

The existing aperture, for the Miele KM 391 G gas hob, is looking like it's 916mm x 500mm so we're really after a 900 hob. The "90cm" AEG and Neff induction hobs I've looked at all require a cutout of 880mm x 490mm.

The "stainless frame" option is looking more and more attractive although I might be getting ahead of myself a bit - we haven't actually had a look at a real life induction hob yet. Still, it's something to have a think about while we're stuck at home and the electrical shops are all closed.