glass tile border grouting

I have a glass tile border: Maggiore Arch, I am not sure how or whether to grout it. This is a bathroom border going through the tub area. It is made of multiple pieces of wavy glass, very closely placed together. Need help fast as I have already started the project. Write back soon!

I can't imagine why the people that create those mosaics think it's OK to jamb tiles together. The small spaces are difficult to grout. In a shower environment I think it is totally necessary to grout the cracks or they could harbour mold in abundance.

Use unsanded grout and close up the holes.

Can I use the grout as the mastic

Can I use the grout as the mastic

No.

You also can't use mastic for glass tile installation. You must use modified thinset mortar.

I'm wondering if the terms used to describe tile adhesives are being confused. Mastic comes premixed in a bucket and has limited uses, shouldn't be used with glass tile. Thinset comes in dry powder form and you mix it with water to create a suitable paste.

THanks Bud

This work out great. This new glass tile is nice but what a pain in the butt. I was told by a friend to use thin-set for the whole bathroom because of the large tile 10x16 but I already had purchase the mastic. Thank god I still had a some thin-set lay around. Finish the bnorder last night. This new glass tile is nice stuff but difficult. Now I have to grout it. Thank you for your advice

For those that care------

Thinset has a shelf life and should always be purchased fresh.