Tuesday, August 2, 2016

Another Table Top

Years ago, I bought a "Turkish Grill" (which is a large copper bowl on a low stand) to use as a fire-pit on my deck. And I built a stand for it to raise it up to about 50cm off the deck so that it would be comfortable to sit around in deck chairs (as we do here, rather than on our haunches as I imagine the original users would have).
And then I also got creative and built a perimeter "table" that was about 30cm wide and got some small and expensive coloured glass tiles and made a nice mosaic pattern for the table-top...

Skip forward about ten years and that perimeter table-top that I made has seen better days. It was built by gluing the tiles to cement board and then grouting in the gaps, but over the years it has not stood up to the test of Vancouver winters with lots of rain and freeze-thaw cycles etc, and its become rather tattered about the edges... And I have to admit that though it looked nice, it was not actually very functional since it wasn't wide enough to use as a real table, and cold drinks do tend to get rather hot when placed only cm from a fire! (yeah, maybe I didn't really think the whole thing through in the original plan :)


So, its time to either rebuild it or throw it out. And since I spent so much on those pretty tiles I decided I should try the rebuild path...

So, first I had the laborious task of peeling off each tile and individually scraping off the adhesive and the grout... It took me about a month to slowly work through that task!... There were about 5000 individual tiles to "process"!

The original perimeter table-top


Detail of the original mosaic pattern.
Its supposed to be the sun in the centre and ocean waves around the edge.

 But rather than duplicating the old design, I decided that it would be better to just make a dedicated table for use on my deck, separate from the Turkish grill/fire-pit. I figured that a table of about 1m diameter would be good, and I wanted to duplicate the same style of mosaic pattern cos I liked the original a lot.
So, first I did some arranging of tiles to try to determine what the new repeating pattern of tiles should be...
Initial pattern for 30degree repeats.

More detailed pattern.

Then it was time to build the table...
I decided Id try to cast the table-top out of reinforced concrete so that it would last better in the winters here... And to ensure the tiles were really solidly bonded to the concrete I decided to build the table in an inverted layer-cake fashion.
So, I made a 4-5cm high perimeter wall with a strap of flat steel and "glued" it down to a sheet of melamine board with bees-wax. Then I covered the board inside the perimeter with a thin layer of bees-wax so that I could stick the tiles down and slowly build up the full mosaic pattern.

The perimeter, the segmented circular plan, and the tub of all the tiles.

The melamine board covered in wax ready for pattern building.

 Then over the next week or so I spent hours sitting on the deck pushing tiles into the layer of wax after the sun had warmed it up and made it soft.




The final mosaic pattern finished and ready for the concreting stage.

Then the big day came and I got a bag of high strength concrete mix (contains higher percentage of cement than usual as well as synthetic fibres that give it lots more tension strength than regular concrete.
So, first I mixed up a small batch of the concrete but I added  lots of black grout mix to it and removed lots of the larger gravel from the mix (before adding the water) with a sieve. I spread this over the tiles and worked it in to all the gaps.
Then I immediately mixed up another batch of the concrete with full aggregate and somewhat less grout, and spread that over the first layer. Then I laid a couple of sheets of wire mesh with a 1.25cm square pattern (pre cut to fit inside the perimeter circle) and poured more concrete over the top and made sure it was well "bonded" with the previous layer of mix.

... And then I found I was out of concrete but my slab was not thick enough ... (typical lack of full planning by me )... so I rushed off to the hardware store and got another bad of concrete mix (slightly different type but still with fibre reinforcing) and mixed it up and filled the last of the perimeter.
Then it was time to wait...

I waited three days and then, with the help of a friend, flipped the whole cured assembly upside down and left it on the deck again for the sun to warm it... It warmed the dark coloured melamine board and softened the bees-wax that was gluing all the tiles to it and I was able to peel the board off to reveal my ne mosaic table top... A bit of work with a propane torch and a polishing rag and voila!
I have a new table top that is extremely heavy!

Then I looked on the local buy and sell site and found an old cast-iron table base that someone was getting rid of, brought it home and spent a couple of hours stripping off the old crappy paint and rust. Then I sealed it up and put the table-top on and the final product looks great :)

The end result.

Lets hope it lasts a bit better than the last one :)