Mark Sunderwirth Posted March 11, 2019 Report Share Posted March 11, 2019 Hi, I bisque fired this red sculpture body to 04 and got these light patches and don't wash off or fade with canola oil rub. I wanted to show the piece unfired. Causes? Solutions? Thanks, Mark Link to comment Share on other sites More sharing options...
liambesaw Posted March 11, 2019 Report Share Posted March 11, 2019 Soluble salts migrating to the surface when drying is my guess, I get it sometimes with the dark clay I use. Link to comment Share on other sites More sharing options...
glazenerd Posted March 11, 2019 Report Share Posted March 11, 2019 Your guess would be correct Liam. Nep Sy was used as the body flux. White vinegar lightly brushed will help some, but usually migrating salts bleach out color. After washing try applying red iron oxide, and wiping off: to stain those areas. Soluble salts in raw clay below. Link to comment Share on other sites More sharing options...
neilestrick Posted March 11, 2019 Report Share Posted March 11, 2019 It's what we call scumming. Is it a commercial body, or do you mix your own? if you're mixing your own, put 0.5% barium carbonate in your clay to prevent scumming. Blend the barium with water first so it disperses well, or you'll get white specks in the clay. Link to comment Share on other sites More sharing options...
Mark Sunderwirth Posted March 12, 2019 Author Report Share Posted March 12, 2019 Thanks for the quick reply, guys! I'll definitely try your advice, Glazenerd! Ch33rs! Mark Link to comment Share on other sites More sharing options...
oldlady Posted March 14, 2019 Report Share Posted March 14, 2019 can you post a photo of the entire sculpture, it looks very interesting. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.