Drilling knockout for Composite granite sink

Once again I call upon the vast knowledge of this board to help me out.

I ordered a Blanco composite granite sink and forgot to have them drill an additional hole next to the center hole it comes with. It is on its way and I will need to open up an additional "knockout". There are 7 knockouts on this sink. Are these "knockouts" really knockouts or are they just a premarked area that have to be drilled out?

If I have to drill a hole how should I go about doing this? I believe it is about 1.25 inches in diameter.

thanks,

Dave

you should have directions for knocking out the holes with the sink . if not get them. do not drill them

http://www.blancoamerica.com/instructions/DropIns.pdf


here are the istructions

If they have stickers on the finished side of sink showing locations of the holes,


don't assume those stickers are directly over the knockouts. I installed a moenstone sink last week, was working tired and started pecking on the knockout sticker like the first one I did and had no problems.

Turns out the sticker was off an 1" and all those pecker marks could of cost me a $600 sink no one wanted.

Pulled the sticker off, used a 1-3/8" carbide hole saw and centered it over all the dings I put in the sink and took care of the mishap.

Never again will I trust the sticker locations.

thanks

Thanks for the information. I was just trying to think ahead as to what tools I would need if I had to drill. Contacting Blanco was my next step but I figured it would take a while for them to get back to me.

If I am correct, the blanco sinks are a composite similar to Corian? These can be drilled with any hole saw. IF it is really a granite composite like Silestone, these need more serious tools.

composit

jimbo said:

If I am correct, the blanco sinks are a composite similar to Corian? These can be drilled with any hole saw. IF it is really a granite composite like Silestone, these need more serious tools.

Click to expand...

They are made of 80% granite with the rest being essentially a resin or plastic.