WarmGlass.com

I'm about to embark on screen printing enamels and have a couple of questions that I'm hoping you experts can help me with.

- Does the grain size of the powder matter? I notice Fuse Master is 340 mesh and Thompson Enamels is 80 (not sure about Ferro). Once you mix it with a medium does either work the same in the screening process?

- In my limited enamel experience, I've had issues with red. Is the Ferro red better? Some reds can't be mixed with other colors - is the Ferro picky that way, too? Would I ever be able to get purple or orange by mixing red with blue or yellow? Or even lighten it with white to get pink?

Thanks, guys!

Nancy

Here's a link to some Ferro information.
http://www.ferro.com/NR/rdonlyres/668A8 ... nshine.pdf

grain size of the powder matters. Fuse master and Ferro colors are equivalent in powderivity. Don't use Thompson's enamels for anything unless your life seems agonizingly long to you, or you enamel on metal.

mesh size is certainly critical to match frit size. Ferro reds need oxygen, so if you fire them on the top surface, they will be fine. When I have encased Ferro reds, they turn black. Be sure to know what temperature the colors you use are designed for. Cadmium containing colors are easy to overfire.

I'm afraid I have no disagreement with Don... And, I did successfully screen print with Thompson 80 mesh enamels. Before I stopped using their enamels over 2 decades ago.

Don Burt wrote:
Don't use Thompson's enamels for anything unless your life seems agonizingly long to you, or you enamel on metal.

UUUURRRRGGGHHHH! Don, please shed some light. I have 20 jars of unopened Thompson's enamels which came with a slightly used kiln I bought. So far I haven't used any as they appear to be for stainless steel and window (float) glass according to the labels. They are 6000 (transparent) and 5000 (opaque) series. I'm tottering on the brink of painting something on float, as I have them.

There are also several unopened jars of Thompson lustres. This has been discussed in another thread about micas.

Am I risking my life or just my sanity? Since I have them anyway and didn't choose them, can you offer any insight into their use? Thank you, Jen

Rats, I had high hopes for the Thompson - I test fired some pink and it was beautiful. I have some of their 7000 series, which are for fusing on glass.

Thanks for the Ferro link, I'll check it out.

Bert, thank you!

I've had problems with compatibility (I presume, cracking and chipping) with Thompson's. Plus I don't like to sift through stencils anymore, although I used to enjoy it. I got hooked on brushwork and airbrush. I've never used the supposedly float-compatible version of Thompson's. I have sample sets I made of the 7000-8000 series on Blenko glass that are still intact. They certainly hold up to fusing temperatures in terms of color and pigment density. I discourage people on here to get into them, because there are Sunshine enamels available here through Brad that are more versatile and may be applied in a thinness that doesn't cause cracking, on multiple types of glass. Here's a picture of my Thompson samples...they were made probably 12 years ago and haven't chipped. But you can see they could stand to be more heavily applied. If that that fuzzy edged form with detail about like my little numbers on the samples is the best you can achieve, why not just use BE or Sys 96 powder and be assured of compatibility? Or use Sunshine, or Fusemaster or similar stuff you can really paint with.

Yes to everything Don said. Thompson frits are made much like Bullseye frits. As such, they require compatible glass. The essential difference is that Bullseye tests their glasses so you can make certain assumptions about fit. Remember that glasses have about 6 points of stress before they crack one or the other. When 2 glasses sit towards the high end of that scale, they might remain stable for a long time, and then again, a gust of cold air could pop a crack. Bullseye has ways to evaluate where their glasses sit on that stress scale.

Float glass, in particular, is all over the map relative to consistency in the properties that create compatibility. The manufacturers don't care an iota about these properties. They have a long list of ones they do care about. In the marketplace, float glass is a commodity and you haven't a clue where it was manufactured, unless you purchase a 2 ton case that is marked with it's factory of origin. Even these are getting harder to come by, as most glass these days is delivered in sling packs with just fiberglass bands, no wooden cases. Most wholesalers maintain more than one source of glass, because from time to time, a particular supplier might not be able to ship them everything they need. That said, I have been fortunate that my supplier has a primary source that happens to be compatible with Youghiogheny EZ fuse. However, the only way to know if 2 glasses are compatible is to test them. And, even then, you can't be sure.

So, yes, I too prefer to use the onglaze style of colors where the colors are strong, and compatibility is a non-issue because they are applied in such thin layers.

Thanks, guys. Lot's to think about here!

I read that Sunshine isn't available anymore but I do think I'll try the Ferro. I'm also looking at another brand that says you can mix the colors and also screen it. The colors don't look quite as bright on my computer but you know how that goes!

Thanks, Don and Bert for the detailed information. I don't sift through stencils, I paint, so will probably stay with the glass paints that are formulated for that and won't waste my time messing about with the Thompson enamels for float. In the unlikely event that I ever get bored I may make up a sample sheet, then again, if I wouldn't use them, why bother?

I was not aware that they would have to be applied so thickly that compatibility would be an issue. Glad I asked! Thanks again. Jen

My apologies, it's the Paradise Paint that is no longer available, not Sunshine.

nbobb wrote:My apologies, it's the Paradise Paint that is no longer available, not Sunshine.

Both the medium and the frit used in Paradise paints are no longer available. Sunshine series is a close match frit. You can still get Ferro medium 175, but it is quite different from the olden days.

I use float glass with Thompson Enamels successfully. I have seen some finished pieces that were first fired tin-side down enamels on top and then the piece was turned over and slumped with the enamels against the mold. What kind of release would I use to keep the separator from sticking to the enamels?
Thanks,
Nina

Nina Kuberski wrote:I use float glass with Thompson Enamels successfully. I have seen some finished pieces that were first fired tin-side down enamels on top and then the piece was turned over and slumped with the enamels against the mold. What kind of release would I use to keep the separator from sticking to the enamels?
Thanks,
Nina

Thompson enamels are much like Bullseye or 96 frits. They are crushed glass that starts out with a strong color, so when applied thinly, it still reads some color. So do whatever you would do with any flip and fire, fire on kilnwashed shelves or kilnwashed shelf with fiber paper on it.

Sounds good but doesn't work that way for me. It picks up the kiln wash or paper and you can't wash or scrub it off without removing the enamel layer.

Bert Weiss wrote:

Nina Kuberski wrote:I use float glass with Thompson Enamels successfully. I have seen some finished pieces that were first fired tin-side down enamels on top and then the piece was turned over and slumped with the enamels against the mold. What kind of release would I use to keep the separator from sticking to the enamels?
Thanks,
Nina

Thompson enamels are much like Bullseye or 96 frits. They are crushed glass that starts out with a strong color, so when applied thinly, it still reads some color. So do whatever you would do with any flip and fire, fire on kilnwashed shelves or kilnwashed shelf with fiber paper on it.

Would there be an issue with compression of the tin side when the piece is re-fired to slump? I haven't tried it but seem to remember the advice is to fire tin side down, or does that only apply when firing the enamel and it's OK to fire tin side up when slumping as the slumping temps are not high enough to affect the tin side if it's up? Confused....Jen

The tin side is an issue only for enamels and frit that contain the precious metals silver or gold.

There is silver in silver stain and gold in the purples, violets, purplish pinks, and purplish reds.

You will know you have precious metal based enamels and frit because they are really expensive! Everything else is fine on the tin side.

Pete

You fire tin side down to prevent a rough surface. Don't slump tin side up. Compressing the tin side creates the fogging.

Tin reacts with other metals as well. Cobalt blue will turn browner (still a nice color). Turquoise (copper) will turn ugly brown. Not all colors are effected though.

When I make sinks with color encased, I only use colors that can handle being in contact with the tin, so I can put the bottom piece tin side down and the top side air side up.

That's what I thought, Bert, from your many posts on the topic. I was responding to and looking for clarification on Nina's observation about enamelled float she'd seen that was apparently slumped paint side down and tin side up........which breaks the rules. Jen

Jen

The tin side protects the bottom from picking up roughness from the kilnwash. I mix micas in when I fire paint side down. This seems to work fine. So, in the case of painting on the air side and firing tin side up, everything is good, unless you want to slump the piece in to a mold, at which point you will be compressing the tin side. When I am making bowls, I tend to use colors that can play well with contact with the tin side. Then I can get the air side up for the slump.