Friday, September 7, 2012

Ottawa River Pot - Black Sand and River Clay

The Ottawa River beaches around Deep River are striped by bands of black sand. Our children used to have great fun picking up the sand with magnets as the black colour is due to iron minerals.
small magnet picking out the black sand
Having seen Navajo sand paintings in the American Southwest this winter I decided to develop my own version of a sand painting. Instead of using glue as the Navajos do to attach the sand I use glaze. The black iron particles melt into the glaze creating a black pattern.

First I concentrate the black sand by picking and repicking the sand a few times with a magnet. Then to be able to paint with the sand I need a suspending agent - I could use wax but that will repel the glaze. I cooked up some flour, water and sodium silicate to a consistency to thick cream. The sodium is so that once the pots are bisqued, the sand will not readily fall off when handling or glazing. I find that using just a thin MD shino  with a top spray of soda ash gives me a nice orange colour that contrasts well with the black sand. I also tried stencils as the Navajo do but as I do not like using commercial ones, I need to make my own and that is very time consuming. So I mostly use brush decorations.

Mugs, tray and teabag rest with black sand brush decoration and shino/soda ash glaze. I also tried using stencils as for the fish.
For the mugs I glazed the inside again with a local material - clay found in the Ottawa River in Deep River. Although we are surrounded by sand - Deep River is built on sand dunes left from 10,000 years ago when the glaciers retreated and we were then on the edge of the Champlain Sea,- and our sand beaches rival any of those found in famous resorts, in a few places if you dig down in the river's edge there are layers of clay. When fired it gives a nice glossy brown. So that is the Ottawa pot and I sell them with an explanation about the sand and glaze - which helps them to fly off the shelves!.


  1. Great looking pieces! That "iron glaze" really stands out.

  2. When the sand is thickish, then the design gets a bit of a wrinkled look which I also like - however I think I will have to test it in the microwave in case it gets hot when that thick - never thought of that until someone this weekend talked about one of their iron glazes getting hot when microwaving.