Cutting Hole for Sink in Solid Surface Countertop

I'm building a vanity for a master bathroom using a solid surface (SS) countertop with an undermount sink. The countertop is just shy of 1/2" thick, about 12 mm. I've been studying the internet for information about how to cut the hole in the SS. There seems to be two schools of thought. In both cases a template is used with a router. The first method uses a plunge router and recommends a minimum of 2 passes, cutting about 1/4" deep per pass. The type of router bit is not stated. The second method has a hole drilled in the center of the cut out with a hole saw. Then a straight router bit with bearing is inserted into this hole and cuts of the entire sink cutout in a single pass. That is, the full countertop thickness is cut with a single pass. In both methods a sacrificial piece of plywood is underneath the countertop during the cut to support the cutout during the entire cut.

I'd appreciate any information and recommendations on these two methods or if there are any other methods the membership would recommend for this process. In particular, please provide detailed information of the type of router bits recommended, including whether the template is on the top or the bottom of the countertop and if the router bit has a top or bottom mounted bearing.

Thanks.

Bob

what type of sink is it?

The sink is Vitreous china.

Bob

Assuming the vanity sink is not square, I would simply jig it out with a fine toothed blade, then sand with a flexible sanding block. No point in making and sanding a cutout just to make one more cut out. The router and template approach makes sense in a production environment where one expects to see the same standard sink shapes over and over again

Bob,

Of the two methods you mention, I can only recommend the first as most manufacturers recommend that, for hand held router use, that you cut no deeper than 1/2 of the diameter of the shank (or bit, if it is smaller).

Now, a caveat here that you may like better than either option: Use a jig saw or other device to cut close to the lines (~1/8" - 1/16") but on the waste side. Then use the bearing-guided bit for a full-depth cut but really shallow. It will give you a very clean result, be safe and your bits will last much longer.

Just my $0.02..

Jim

Bob

I have installed a SS kitchen counter and used a 1/2 inch straight router bit as sold for cutting regular wprktops and used may be 2 or 3 passes ( extra passes will not ruin your day).

I used the bushing guide and template and the template has to be 9mm larger than your cutout. Did they supply a template with your sink?

Transfer it to piece of MDF, move the line out by 9mm and create a template. Place template on your SS and route away to your hearts content.

regards

Graham's method is a viable alternative; the key is the multiple passes. :)

Last year we had a new quarts counter top installed by pro's. They cut the sink and cook top openings in it using a diamond saw blade and a hand held circular saw. I saved the cut outs and made a small table to support our microwave with it. I purchased a tile cutting saw blade made to work without water. It cut quickly and very well for me in my skill saw.

I know people use jig saws cut cut solid surface materials but DuPont does not recommend it in their installers' manual.
Attachment 253844

I cut mine with a router or roto zip

I presume that you're talking about an acrylic-based counter material.
Router with guided bit and multiple passes is the way to go. Too much cut, and the acrylic does bad stuff. I'm hopin' that you'll inbed the the anchors for the brackets to secure the sink.
Bill

The countertop is acrylic-based solid surface.

A few manufacturer's have recommended against using a jig saw for cutting the SS, because of the possibility of this leading to cracks in the SS in the future. I suspect they are being overly conservative, but maybe not. I'm thinking of using an upcutting straight spiral carbide bit in a router with a guide bushing and a template, taking 3 passes to make the cut. The sink manufacturer supplied a cardboard template, but it's not even close to matching the sink. I'll make a template based on the actual sink rim.

Since the SS is so thin and I'm not adding additional reinforcement strips underneath the SS, I'm planning on using the epoxy-embedded studs to secure the sink to the bottom of the SS. I'll also fabricate some removable wooden beams to go under each end of the sink lip just in case the epoxy fails. Sort of belt and suspenders, but, I'd prefer not to install the sink twice.

Bob

There are things I know I can do, there are things I know I can figure out... This is one I could figure out but would pbly take it to a professional countertop shop and pay them to cut it for me... Guaranteed outcome and less hassle. They will likely let you watch making it easier for you to do the next one...

Good Luck