Saturday, June 14, 2014

Cleaning Kiln Shelves: YouTube Review

Kiln Shelves, Kiln Shelves -- So important for getting a good base on your piece

I'd be really interested in getting a few more people in the studio (our lovely volunteer co-operative) who clean kiln shelves. I think there are some now, so I thought I'd give a little review post on some youtube videos out there.

There are so many experts out there giving (sometimes conflicting) tips out there for cleaning electric kiln shelves.  Most of them are dealing with nice flat undamaged shelves. Our studio uses the cordierite or high alumina kiln shelves (good for fast heating and cooling, cordierite warps above cone 8) and not the silicon carbide type (due to expense, increased safety hazards in our electric kiln as they're a conductor).  As we fire cone 6 we use the thicker 3/4" shelves as the thinner ones with warp at our temperatures and most of our newer shelves should be the high-alumina type.

A full round 3/4" high-alumina shelf costs about $75+tax, and a half shelf about $40+tax. We want them to last as long as possible in good condition so people's pieces will turn out nicely.

If you're interested in trying to clean the shelves, we have some printed instructions.  There should be some dust masks and protective eyewear in the glaze prep area.  Ask for help and a demonstration.  Will post on the board to see if we can organize a session.

TENTATIVE DATE: I'll be doing a bigger shelf cleaning session soon if you want some practice. I'll be trying out the side-grinder.  Bit weather dependent as I want to do it outside: a) Wednesday June 18th (evening), Friday June 20th (afternoon or evening) or Sunday June 22 (morning or early afternoon).

General protective gear tips: 

  1. Always use eye protection when cleaning or grinding shelves (tiny bits of glass + eyes = not good )
  2. Use a dust mask or respirator whether you're working inside or out (tiny particulates + lungs = not good long term)
  3. Consider the circumstance and choose level of protective gear you need otherwise (gloves, covered footwear, etc.)
Sample videos below: 

1) Potter Tom Zwierlein goes over some tips and demos using a chisel, side-grinder, scraper, washing and applying kiln wash. Longer overview with some side comments.

Applicability: Nice overview, but I think he's able to keep a lot more control over his studio conditions.  We have a lot more variables and people in out.  Lovely nice flat undamaged shelves...

Protective gear: goes over different types of gloves and uses, he uses a fan to blow dust away and works outdoors instead of a dust mask, uses sunglasses to cover eyes.

2) Jeni Hansen Gard goes over why kiln wash is eyes, mixing kiln wash, applying it and storing the shelves kiln wash side to kiln wash side.   Nice beginners intro although I think she'll improve her brush stroke pattern more over time.

Applicability: uses different recipe for the kiln wash than in our studio, but basics the same. I like to use a small whisk in the mixing process. We have kiln wash right up to the edges but she suggests avoiding that to avoiding flaking into pieces below.  I think keeping sides of the shelves clear of kiln wash, not applying it too thick (want to avoid cracking), and scraping it down properly better for our studio.

Protective gear: uses dust mask, goggles. She doesn't wear gloves, but also doesn't show the actual cleaning of the shelves where cuts from broken glass shards are most likely (tip: never "look" for remaining glass shards by running fingers over the shelves...).

3) Expertvillage goes over a very quick demonstration on using a side-grinder to get rid of glaze bits stuck firmly to the shelves.  Giving this one because it's fast and one other reason (see below).

Applicability: None yet, but I want to organize a session or try using a shelf grinder to clean up our shelves and flatten them out more.

Protective gear: Does it outside, and uses dust mask and protective eye-wear... and then proceeds to bend over and work at it at an awkward angle wearing flip-flops. FLIP-FLOPS.  I've seen too many safety videos over the years.  All I could picture was the end bit where it went "and when she wobbled a bit, she ended up losing two toes".  At the very least wear covered-toes shoes to provide minimal protection. Something thicker, like leather, would be better. Gloves nice too.