Undermount Sink Epoxy Recommendation for 3cm Granite

[traylord]

I am planning to have a seam at the center of an undermount sink.  The granite is 3cm Tropical Brown.  
What are the pros and cons of having a seam at the center of the sink?

What is the epoxy and coloring you recommend for this application and how much do I need?

[Mark D.]

If you make the seam correctly there are no cons, but I like the seam placed on one side or the other myself. As far as structural integrity, if you have proper support from beneath it makes no difference. Are you centering the seam for symmetry? If that is the case you might go for a seam on both sides instead.

As far as the glue goes, you can use epoxy or polyester resin for a seam (the poly glue may ONLY be used if there is no structural integrity involved. I define structural integrity like this: if the glue bond breaks & something can fall down that would be structural integrity. If it is supported from underneath, you can use polyester resin glue as the slab is not going to fall up.).
Make sure you use a knife grade glue, not a flowing or water viscosity glue. We actually have a DVD with a 30 minute segment on doing seams with polyester resin. You can find it here:
http://www.defusco.com/fabricating-stone-for-the-doityourselfer-glues-sealers-p-2299.html

Here is my recommendation for epoxy:
http://www.defusco.com/rivo-knife-grade-epoxy-p-1427.html
or
http://www.defusco.com/instant-install-minute-epoxy-32oz-knife-grade-p-2423.html

Here is my recommendation for polyester resin
http://www.defusco.com/tenax-knife-grade-polyester-liter-p-1432.html

Here is the color kit I recommend:
http://www.defusco.com/6pc-tenax-poly-color-kit-p-1439.html

Given the choice, I like the polyester resin better. It is easier to work with, sets up in just a few minutes, and if enough pressure is applied to the glue joint it will give and have to be re-glued, while if the same pressure is applied to an epoxy joint it won't give which will cause the slab to break next to the glue joint.

If you have any other questions you can call me at 800-289-6834.

Glad to be of service,
Mark

[traylord]

Thanks Mark.

I got the videos the other day, but haven't had the chance to watch them completely.  I'll watch the segment on resin tonight.

I am centering the seam for symmetry, to make it as small as possible, and the end of the slab stops right in the middle of the sink.  There is good support to the front and rear of the sink, so the structural integrity should be good.  I am using a single hole type faucet and it will mounted directly through the middle of the seam.  Do you have any concerns with that?

Thanks Again,

David

[Mark D.]

I personally don't like the idea of core drilling through granite with a seam. If you pop the seam you create more work.
That being said, if you use one of our high speed core bits it should do it quickly and with almost no pressure to the slab. Try this:
http://www.defusco.com/38%E2%80%9D-58%E2%80%9D11-seg-dry-stone-core-bit-vbb-p-2377.html

Glad to be of service,
Mark