Building soapstone sink

[rgistone]

I have a customer that would like me to build them a sink out of the soapstone we are doing for their countertops. I am basically just making a rectangle with a base and a divider. i don't have the capability of dishing the bottom for drainage. the customer knows this and is fine with it. the sides of the box will be mitre fit together as the sink will bump out slightly from cabinet.

the bottom of the sink, should that be mitred to fit the sides or can it just be a rectangle that sits inside the four walls?

this is the first time i'm doing this so i'm just throwing it out there to the pros to see if anything comes back.

thanks in advance,
mick

[topshop]

I have never built one personally but I would think that if you can do a dato cut the seam would lock in and be stronger. These joints are used in wood working all the time and give the ability for more adhesive strength.

[Mark Meriaux]

If you're going to miter the corners, then you likely possess the skill to grind/slope the bottom.

On the few sinks that we've done (ES, granite, and soapstone), we use butt-joints. I cut the bottom as a full solid piece, with the sides and back sitting on top of the bottom. I design the front face full height so it is in front of the bottom piece, hiding that seam. The only visible seams after it's installed are on the front left and right sides. Here's a simple schematic:

Sink.gif (5.24KiB)Viewed 901 times

To slope the bottom, first cut the hole for the drain. Then cut a recess for the drain flange and leave 1/2" of material thickness where the flange mounts. I then put some layout lines on the stone from the corners to the drain center and start grinding with an aggressive cup wheel and a lot of water. You can tape of the edges where your dado/miter/butt-joints are going to be. Start by grinding the most material along those diagonal lines, then blend the whole thing together. Use a straight edge across the piece to check the slope in different directions. Once you get close to the shape you want, use your regular pads and bring it up to a hone to match the tops.

Use a good full epoxy to assemble the pieces. We prefer Touchstone Edge 2-part epoxy. Tape off all surfaces next to the edges being glued up - makes for way easier cleanup. Clamp them and allow to cure overnight, then you can use you pads again to go over the exposed areas of the sink to remove excess glue and smudges.

[Kowboy]

Mick:

Someone posted on this site or stoneadvice a while ago that they built a sink but couldn't get approval from the inspection division because the custom-built sink was not approved by some government agency. If this is new construction, this may be more of a problem than on an unpermitted remodel.

You should make your customer aware that this problem could arise and agree in advance as to how it will be resolved if it does.

Good luck,

Joe

[Chicagostonepro]

Great description Mark.

I agree, in Soapstone, Mick, you should have no trouble pitching the bottom plate by grinding.

For granite and engineered stone, we normally split the bottom plate into four and glue it back together to get the pitch. It's a little different in that the four sides are the full height, set to the sides of the bottom plate. Once you have a system down, it goes pretty fast. The epoxy cure time is the slowest part.

We use Akepox 2010.

Here's a pic of an engineered stone vanity sink I designed that shows a split bottom plate:
http://chicagostoneshop.com/gallery/ind ... alemGold-2

Sorry about the long url.