Shelf Primer dust

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Cherie Knopf
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Shelf Primer dust

Post by Cherie Knopf »

We use Bullseye Shelf Primer on our kiln shelves and fuse all of our pieces on the shelf directly. We've let it go several times before we re-apply the wash. It always seems to have a really fine powder on the shelf all the time. Do you all clean /vacume shelves after each use? We notice sometimes we are now getting so much powder on the new fused item. So really two questions, should we be getting rid of the powder each time and if we do have the white powder on the glass item, what is the best way to get it off - we tried the different fine grit hand sanders and it just doesn't seem to work well - always left with a white residue.

Thanks!
Cherie
Cheryl
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Re: Shelf Primer dust

Post by Cheryl »

mist the shelves in between firings
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Cherie Knopf
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Re: Shelf Primer dust

Post by Cherie Knopf »

So you recommend just a mist across the shelf, do I then rub it down at all or just let it set?
Stephen Richard
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Re: Shelf Primer dust

Post by Stephen Richard »

Cheryl wrote:mist the shelves in between firings
What does this mean?
spray with water
spray with kiln wash
remove dust before spraying

I'm not sure what I am missing here
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Bert Weiss
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Re: Shelf Primer dust

Post by Bert Weiss »

After the kaolin, which makes up half the kilnwash formula, goes through it's quartz inversion, It may cause problems in subsequent firings. If you are getting sticking, I'd consider blaming used kilnwash. A thin fresh coating is all you need to cover the existing wash.

Opals are more prone to sticking than transparents. An iridescent coating is the best protection from sticking.
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Morganica
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Re: Shelf Primer dust

Post by Morganica »

Hmmmm. I deliberately CREATE dust on the kilnshelf by polishing it lightly with a paper towel and then pushing the dust into the wash. It gives me a smoother back glass, seems to prevent sticking and makes it much less likely that the opals will pull up the kilnwash. It also lets me get a little more use out of a kilnwashed shelf that's showing tiny cracks--the dust goes into the crack and smooths things down a bit.

I spend so much time making sure there's minimal moisture in the kiln that the idea of deliberately spraying water in there kinda makes me wince. I guess it depends on your workstyle?
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Cherie Knopf
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Re: Shelf Primer dust

Post by Cherie Knopf »

We were wondering if we shouldn't just scrub off and reapply Bullseye shelf primer before each fusing. It just gets to be a lot of work to do it every time though but if we keep having all these pieces show up all powdered and unable to get a clean bottom we probably need to do that.

Just curious for those of you using Bullseye shelf primer, we heard that you apply 5 separate coats (with each coat drying before the next is applied). Going in different directions each time. Does everyone really do that many coats?

Thanks
Cherie
Brock
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Re: Shelf Primer dust

Post by Brock »

I do 10, or so, without drying, and get multiple firings from the shelf. Ensure that you cannot see the colour of your shelf through the primer. But, big but, I don't have opaque colours on the shelf. The base of my work is either irid side down, clear, or transparent, and I don't go over 1450 on these shelves. If your base is an opaque colour, or you are doing hi-temp work don't expect to get multiple firings.
Jeanne
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Re: Shelf Primer dust

Post by Jeanne »

Try giving Bullseye a call. They are usually very helpful in their tech dept. Or you could post on their Forum.
Stephen Richard
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Re: Shelf Primer dust

Post by Stephen Richard »

I and many others spray the kiln wash onto the shelf.
Spray enough so the colour of the shelf is just obscured with the pink colouration of the solution.
A tip pointed out to me that to get a super smooth surface, do a final spray with hot water. The shelf has to be level, so the water on the top can form a puddle which evaporates to as smooth a surface as the grain of the powder.

If you are painting on the wash with a hake brush, there is no need to allow the previous coat to dry before applying the next. The shelf absorbs the water pretty quickly. When I paint, I use four coats -= one up and down, one across, and two diagonally from opposite corners to get complete coverage, not for thickness.
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Valerie Adams
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Re: Shelf Primer dust

Post by Valerie Adams »

I don't understand what you mean when you say you get so much powder on the back of pieces, and then can't get it off. When my kilnwash (Bullseye) leaves a slight bit of powder residue, it wipes right off. Are you sure you're not having kiln wash sticking to the back of your pieces? In that case, you're probably firing too hot. You might want to post your schedule.

I use a haik brush, and do about six coats, without letting it dry between layers (who's got the time?). I seldom fire above 1440° and routinely get 3-5 firings per shelf. I don't scrub the wash off when I re-coat, I just skim off the used wash with one of those razor-blade paint scrapers.

I used to spray my kiln wash on with a pump-style garden sprayer but have reverted back to the brush. Before using a newly washed shelf, I take a piece of regular paper and lightly wipe the shelf down to smooth any brush marks. I don't brush off the excess powder this creates.

Works for me!
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