How to enlarge hole in countertop for new cooktop

KCMike

I recently bought a new 30" cooktop however the exisiting cutout is too small. The opening needs to be about 1-3/4" wider. The countertop is 1/4" tile on top of approximately 1" of concrete on steel mesh which is on top of 3/4" plywood. What tool(s) do you recommend I use to make the cut? The cut is about 19" front to back.
Thanks for your help.

Windows on Wash

Angle grinder with a diamond blade.

You are going to make a ton of dust though so try to get a vacuum equip set up.

__________________

Daniel Holzman

You may be able to cut through everything using a diamond blade on a circular saw. The angle grinder would be used for the corners, or you can probably cut the corners using a diamond or carbide blade on a jig saw. I have cut through concrete block using a diamond blade on a circular saw with no real trouble, just don't try to cut the whole way through in one pass, make say 1/4 inch cuts. As with a grinder, makes lots of dust, so a shop vac would be good, but also wear a NIOSH approved mask, concrete dust is really bad for your lungs.

Windows on Wash

+1

A circular saw with a diamond blade would be preferable for the longer straight cuts.

Proper PPE is a must and be prepared to make a mess.

__________________

epson

I have used a rotozip tool to do many a job similar to this and had great results see link below.

http://www.rotozip.com/en-us/Cutting...spx?catid=5122

ddawg16

In case you didn't get the hint.....it will be REAL messy......make sure you put up a curtain between the kitchen an adjacent room. Cover everthing else with old sheets......and toss a sheet on the floor as well....and have the shop vac handy. And I wouldn't use safety glasses....I would use a face shield along with mask....

There is nothing that is going to kill you chemical wise....but the dust can be bad and is not good for lungs....

__________________
Common Sense is like Deodorant. Those that need it the most don't use it.
My
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
...
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
and
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

itsreallyconc

cutting tile's easy but 3/8" of tile on top of 1" conc over wood isn't,,, this calls for step cutting, too,,, comparing the 2 suggested method's, i'm willing to bet on the rotozip as being the least messy for the tile cut but you'd not get the depth needed in 1 pass,,, we have shrouds on 4 & 7" grinders hooked up to 220v vacs & still there's dust,,, i'd pick a 4" diamond blade & grinder for the tile/conc 1st cut followed by 7" circle saw & carbide blade for the 2nd,,, there are shrouds for both but, unless you're a pro, $200 just for shrouds is a large investment for single use,,, if it were me in your circumstance, i'd let this job out to a c-top pro - hire his tooling & expertise - either cutting wet or dry, it's messy

__________________
taxpayers voting for obama are as idiotic as chickens who voted for Col. Sanders !
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

if you hear it from a guy in the apron store, be VERY suspicious the mtl/method will work,,, when it time to build something together, they won't answer phones NOR help
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

paintdrying

Have you considered buying a cook top that will fit properly. I am still finding concrete dust from 30 years ago throughout my house. I would at least try a chipping hammer before I put a saw to concrete

KCMike

Thanks guys for all your ideas. I really appreciate your prompt help.

Have a great day and a blessed and happy New Year!

itsreallyconc

ixnay on the chipping gun even 1 as light as a bosch bulldog,,, conc has no 'grain' therefore it won't cut straight,,, IF you can live w/jagged edges, it wouldn't be a dealbreaker,,, we routinely saw, drill, diamond core, & chip conc for a living - that's what we use for the reply's basis

another note - op already bought the cooktop - i'm sure the suggestion of a smaller top's already been discussed

__________________
taxpayers voting for obama are as idiotic as chickens who voted for Col. Sanders !
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

if you hear it from a guy in the apron store, be VERY suspicious the mtl/method will work,,, when it time to build something together, they won't answer phones NOR help
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.