Enlarging a Corian countertop cutout

[lumchovack]

I have a cooktop cutout in a Corian countertop that measures about 30" X 24" and need to enlarge the opening to accommodate a larger replacement appliance. I would appreciate advice regarding the tool(s) most appropriate for the job and importantly, how can I maintain an even cut parallel to the existing edge? Some degree of precision is required. Is there anyway to use a Festool Guide Rail plus router (or jig saw) to enlarge the opening? Thank you for your help.

 

[morgan]

Cut some 4" - 5" strips of 1/2" mdf or similar material to make a template. Use a hot glue gun to glue the outside edge of your template to the counter then use a router with a flush trimming bit and have at it.

 

[Administrator_JSVN]

Welcome to the forum.

One of our trainers, Steve Bace, has decades of experience with counter top fabrication and installation. I could have him give you a call to offer some advice. Unfortunately, I don't have enough experience with those applications to offer any input.

Please send me your contact information and I'll have him reach out to you.

Shane Holland
Festool USA
sho@festoolusa.com

 

[WastedP]

Cut some 4" - 5" strips of 1/2" mdf or similar material to make a template. Use a hot glue gun to glue the outside edge of your template to the counter then use a router with a flush trimming bit and have at it.

Exactly what I would do.

If there's a lot of material to remove (greater than half the diameter of the router bit), I first rough cut about 1/8" less than the amount I want to remove, using a circular saw.  I then use a hot-glued mdf guide, clearing out the corners first to finish the saw cuts, then clean it up with the router.  I was taught to never use a jigsaw or a belt sander on solid surface because of excess vibration from the former and heat from the latter. 

Avoid squaring the cutout if at all possible, if I remember correctly, most fabrication manuals specify a 3/8" minimum inside corner radius.  At install, I take a roll of the metal foil HVAC tape and apply it all the way around horizontal surface of the cutout with the excess folded back inside away from the edge.  The idea is that it is supposed to function as a heat sink.  I don't know if I believe it's truly effective, but it was SOP at the shop I first learned solid surface fab from.

 

[Birdhunter]

The Festool MFS 700 would look to be perfect for the job. I have the MFS 400 and, combined with a template follower router setup, cutting exact sized and exactly positioned holes becomes easy.

Look at the videos and decide if the MFS is right for your project.

 

[morgan]

the MFS can be difficult to clamp down if the countertop is already installed.  I recommended 1/2" mdf for the template because it is common and most of us probably have it in the scrap bin. You could also use 3/4" mdf. WastedP is right about the inside radius, you definitely don't want it to be square.  If you have a large diameter template routing bit, use that. If you have access to the OF 1400 it would work,  but I certainly prefer the mass and balance of the 2200.

There are really expensive straight edges made for exactly this task... do yourself a favor, keep it simple and use some scrap to make the template. Oh and before you glue it down, wipe the counter down with some denatured alcohol to make sure it is clean and the glue sticks.

 

[WastedP]

Oh and before you glue it down, wipe the counter down with some denatured alcohol to make sure it is clean and the glue sticks.

That's a critical step that I completely took for granted.  After the routing, spray the alcohol along the edge of the mdf so you can more easily pop the glue off of the solid surface.

 

[hawkman0214]

All of the methods everyone has suggested will work. The main issue you may have are the cook top blocks that should be under your countertop. They are a specific size and in a specific location to minimize the chances of your countertop cracking in the corner. This may become more critical if you put in a cook top that has more BTU's than your current one. In a past lifetime I certified Corian fabricators for the Corian distributor I worked for. You can try it yourself, but they are many steps that should be taken to assure yourself you won't run into issues down the road. Shane suggested calling Steve, that is a great idea. There are also Corian service agents all over the country that could do the modification for you. This would eliminate any risk of failure. I'm not sure I would consider this a diy project unless you don't mind potentially paying someone to come out and fix the top if you do the modification incorrectly. My two cents from looking after 200 plus fabrication companies for 8 years.

 

[lumchovack]

Your replies and advice are appreciated. I will take advantage to the kind offer to discuss the issue with the Festool trainer and go from there.