I'm very new here and really happy to have found this forum. I have read other posts on pin holing issues with glazes and I am having the same issue, but i cant work out if they are really pin holes or not. Some of them kind of seem like creators and are smooth indentations on the glaze while others are small sharp bumps.
Here is what I'm using and how:
I'm using is southern ice porcelain clay. I'm firing to 1240 degrees C for my bisque fire. I leave the bungs out till 750 degrees. (I use a small electric kiln)
I use underglazes on the greenware.
I'm using a store bought glaze mix Northcote pottery (here in Australia) They have had a issue of late with a change in formulation due to an ingredient going off shore. This change has caused the glaze to be thicker in consistency and has major issues with it crawling. They have advised to go from 2 coats to 1 careful coat otherwise the glaze crawls, but its far from perfect. If it is slightly thick in a spot it will crawl or cause a frozen ripple effect slight but noticeable. It has also been causing pin holes as shown in the photos. I have been mixing 1:1 northcote pottery stoneware glaze with a cessco stoneware glaze and this has helped with the crawling and rippling and some of the pin holes but has not helped with the pin holes a great deal. This glaze(Northcote pottery)by the way used to be PERFECT and almost fool proof glaze. I'm not just using straight cessco either as the glaze looks less glossy and like there are very slight and very tiny dimples over the surface of the glaze.
Anyway any advice?
I'm self taught but have working with the same materials for 4 years. I need my glaze to be very clear as the designs under the glaze are the feature of my work. I have tried out every other store bought glaze that I could get my hands on in Australia that will fire to 1280 (there are very few) but they don't work as well (or as well as this glaze once worked) or are as clear.