Saturday, April 24, 2010
Mosaic Journey - Learning How to Mosaic a Pot
Spring time brings with it my desire for gardening and this cold, cold winter (yes, even here in Florida!) had me dreaming of mosaicing garden pots.
I did my first pots last December (as gifts) and this was a bit of new territory for me. I did what I usually do and turned to books and the Internet for some how-to. And wow, lots of variations to be found on prepping the terracotta pot: 1.weldbond/water on outside penetrating sealer on inside 2. weldbond/water on outside yacht varnish on inside 3. house paint inside and out 4. weldbond/water inside and out...
I decided to go with variation #2 and to use thin set mortar to attach the ceramic pieces to the pot.
I painted the inside of my terracotta pot with spar varnish. This would seal the interior and prevent water from penetrating and soaking through to the mosaic which would compromise the mosaic's thin set mortar bond to the pot.
The outside of the pot I painted with a mixture of five parts water/one part weldbond glue. This soaked into the terracotta. I chose this method of sealing because it would reduce the water absorption from the thin set mortar. Unsealed terracotta is so porous that it will absorb water from thin set quickly, which weakens the thin set. I also suspect that the weldbond softens a bit from the thin set moisture and then bonds with the thin set resulting in a stronger bond of the mosaic to the pot.
Why thin set mortar? Another common choice would be weldbond. But, I know from experience (glass on glass project) that if moisture gets down to the weldbond- and we are talking about an outdoor pot here! -that the weldbond will go soft and white again. Additionally the weldbond is best for attaching flat surface to flat surface. A silicone type glue would work but I feel the thin set attaches more firmly to porous surfaces. Thin set also excels at bonding irregular tesserae (mugs!) to curved surfaces.
So many choices on what to use to create the mosaic design with. I decided to go with broken plates. (In my location I do not need to worry about freeze/thaw but if you do, look for hardier choices or bring your garden pot inside for the winter.) So I checked my local thrift stores for goodies and also etsy.
These lovely mugs came from ceramic artist Judy B Freeman.
Many ceramic artists on etsy will occasionally offer for sale a box of broken rejects specifically for mosaic use.
To the left you can see that I used thin set under the top brim to even out the surface. And you can see more of Judy's awesome butterflies.
After attaching the design with thin set, I grouted the mosaic as usual (use caution with the ceramic edges- SHARP!) and applied a sealer after the grout cured for three days.
And below are three views of another pot also made with Judy's butterfly mugs as a design inspiration.
See my Etsy MosaicSmith shop for available mosaic art.