Saturday, June 6, 2009
Mosaic Bowling Ball - Part 3
Maggie Mae (top) and Max had front row locations next to my work station in the garage. They bored easily but did enjoy the front yard view when they weren't snoozing. This afternoon I made major headway on this project.
The grout color is a deviation from my original intent to use just Burnt Umber (dark brown), acrylic paint. It was too dark so I custom mixed 2 oz. each of Burnt Umber, lime green and red. It will probably dry a shade lighter but I like the mid-range color that blends well with both light and dark mosaic pieces.
I had to play with the grout consistency - too dry it crumbles, too wet it doesn't pack between the crevices well enough. You can see I thoroughly encased the ball with grout. It looks like a huge mud ball! I think this was overkill actually, but I'm still on a learning curve here. : ) I ended up scraping most of the excess off with my fingertips (wearing Playtex gloves), and then started carefully wiping and smoothing around each piece with a slightly damp (not wet) soft, round mosaic sponge. It took lots of rinsing, squeezing out the excess water from the sponge and then smoothing some more before the grout was smooth and the pieces well defined on the ball.
After letting the ball sit for 30 minutes to set up more, I then wiped the grout haze from each piece. It was important to rinse the sponge and change the water frequently but taking the time to do this now makes it so much easier and quicker to do a final polish with vinegar water once it is entirely dry. (minimum of 48 hrs.)
Since I used acrylic paint and very little water to mix my grout into a thick putty consistency, it will affect the regular drying time for the grout. I chose this additive because I want the flexibility in my grout for our Alaskan winters of freezing and thawing. I also put a cloth over the ball while it drys to help slow it down initially to avoid any cracking. I plan to let the grout dry four days instead of the typical two before I seal it with a few light coats of acrylic spray. The spray will seal the grout, help water proof it and bring out the shine on the glass. I plan on gluing additional clock parts as the final step so one more posting is forth coming. Check back in a week or so.
A side note here: The grout slurry I used to coat a bowling ball as mentioned in Part 2 didn't live up to my expectations. It rinsed off easily. I will resume the scoring process I used to rough up the ball before gluing mosaics to it. I prefer the extra measure of security the adhesion will have.