|
|
Post by Avi on Apr 9, 2016 16:11:34 GMT -6
Go For It!!!
|
|
Kuba
Full Member
SztukKilka in Old Formu
Posts: 111
|
Post by Kuba on Apr 11, 2016 0:38:47 GMT -6
take no prisoners!  |
|
|
|
Post by Avi on Apr 11, 2016 19:00:34 GMT -6
Here are some thoughts on risers and catchers
I make my risers and catchers separately.
I make my catchers out of reclaimed scrap clay. I roll it out and press it into earthenware saucers from a garden supply store.
I throw my risers from reclaimed scrap clay as a tall tapered cylinder then cut cut them off with a needle tool after the cylinder is leather hard. Because the cylinder was tapered each riser has two slightly different sizes. (see drawings below). It is quicker and gives me more flexibility.
I store my risers and catchers bisqued. I match my risers to my pots when they are both bisqued. They should be as close to the same size as possible. If they can not be the same size the riser should be slightly smaller than the pot. I sand both flat on a diamond lap on my wheel with a water drip. Then I lap them together by lightly grinding one against the other. I glue them together using a mixture of EPK and a jelled wood glue. putting the glue only on the riser. Try not to get any glue on the pot.
After the glue has set up but before it is hard I scrape away any glue that has oozed out from the seam. I want to have a smooth surface for the glaze to run past the intersection of the bottom of pot and the riser into the catcher.
As to the issue of EPK vs. Alumina (which is in kiln wash) I switched to EPK because the EPK mixture separated better after firing. Alumina is made up of little balls that do not melt easily. Therefore it tends to wick the glaze between the pot and riser. Kaolin is more clay like (platelets) and forms a tighter seal. The glaze runs by and does not enter the seam. (I got this information from Diane Creber at a seminar I attended with her) And yes, the catcher can fall off by itself when you lift it out of the kiln after firing but then there is almost no grinding. Be careful when removing the fired pots from the kiln. Try to use two hands.
I grind my pots on a diamond lap with a water drip (another full topic)
I used to get separation anxiety and have a lot of grinding after every firing before I switched to using EPK and glue only. I use a stronger glue (see Elmer's E7010 Carpenter's Wood Glue below) with about 50% EPK and that helped the premature separation. I get almost 100% clean separations with no scoring and just a small tap of a hammer or the application of a small torch. They all pop off clean and all I have to do is finish polish with the diamond lap.
|
|
gczop
Full Member
Posts: 202
|
Post by gczop on Apr 12, 2016 8:12:49 GMT -6
As a result of Uncle Phil's Smackdown , switched to Alumina Hydrate from EPK. G
|
|
|
|
Post by adammacmillan on Apr 12, 2016 14:51:26 GMT -6
I used to use EPK, but i would always get some scale that would form on the inside of the footring. I cut a deep footring in most pots. This scale would take serious scraping to get out.
Now I just use a mix of Gorrila wood glue, water, and some nano-alumina a friend gave me. Maybe those tiny balls prevent me from having wicking issues. The remaining alumina is just a powder after firing that washes off very easily.
Also, I use the exact same method as Avi, except i lap both the footring using a 60 grit wheel and pedistal after bisque.
|
|
|
|
Post by Avi on Apr 12, 2016 17:10:45 GMT -6
Also, I use the exact same method as Avi, except i lap both the footring using a 60 grit wheel and pedestal after bisque. Yep, I do the same. Just got back from the studio after doing so pedestal grinding!!! Avi |
|
|
|
Post by wmcampbell on Apr 13, 2016 9:02:49 GMT -6
Hard to believe that we are still discussing how to remove catchers from our pots.
There may not be a best way.
EPK forever!
|
|
|
|
Post by Koz on Apr 14, 2016 11:53:19 GMT -6
Yeah Bill is right.
I don't know what I was thinking diggin' this tired old hacked out topic back up again.
Where was my head? Upside down up to my neck in the slip bucket perhaps.....
Besides, I switched to baking soda this winter. That and white school paste. You know the stuff we used in kindergarten with the little stick on the lid, that also makes a great snack before lunch?
You guys can have your EPK and alumina hydrate. Been there done that.
They both taste like crap anyways.
Koz
|
|
|
|
Post by mariscal on Apr 14, 2016 13:09:06 GMT -6
Hello everyone
50% hydrated alumina
50% EPK kaolin micronized
4% cmc
The density has to be like yogurt
let cool the pot, and with a light blow, detach, half of the pots are separated without touching them
You do not will need torch, it is easy
A hug
Jose
|
|
|
|
Post by Avi on Apr 16, 2016 16:49:50 GMT -6
Besides, I switched to baking soda this winter. That and white school paste. You know the stuff we used in kindergarten with the little stick on the lid, that also makes a great snack before lunch?
Koz
What difference/advantages have you experienced?  ? |
|
|
|
Post by Koz on Apr 18, 2016 8:13:59 GMT -6
Avi,
Well, back in kindergarten the teacher always yelled at me for eating paste.
But now that I'm all grown up, I can do what ever I want to, and if I'm in the mood for a little snack during the day, a lil' pinch of the paste between yer cheek and gum is a great way to curb the appetite until lunch.
The baking soda just happened to be in a box in the back of the fridge at the shop, and it's a white powder so I thought to myself, "What could possibly be the difference?"
So I just put the two together!
The mix is also great to brush your teeth with because of the baking soda in it.
No real advantages or differences other than those conveniences.
Give it a try, let me know how it works out for you.
Just using what I got and saving a TON of money not having to buy pricey white glue and alumina hydrate.
Koz
|
|
morgan
New Member
Darn...lot of good info on the old forum. Sad that it got unstable. But whadya do?
Posts: 21
|
Post by morgan on Apr 27, 2016 5:19:32 GMT -6
I used to use Alumina and wood glue, but found for my application that I had to use dynamite to get the pedestal off the pot. The explosion was often just more than the poor pot could handle, sadly. So... switched to EPK. Started with the pro wood glue but have recently begin using cheap dollar store elmers school glue. Sometimes the pedestal and pot separate when I lift it out of the kiln. Often after sitting overnight they come apart during the "ping" concert. If not, usually just have to tap a few times lightly and voila... However, still have to grind that pesky sharp glaze ring at the bottom. Maybe if I tried doing micro perforations (like those print them yourself business cards)near the bottom of the raw glaze before firing it would just come apart with no further work. lol Wouldn't THAT be cool!!!
But...might give Koz's paste a try. I do like a good snack while working.
Morgan
|
|
|
|
Post by Koz on May 5, 2016 11:19:45 GMT -6
Sooo...Aren't the tumble weeds just lovely this time of year?
I'm just sittin' on the porch watchin' em' blow by in the empty streets of the Forum, strummin' my two string guitar, and I had this thought.
Is it possible that there are different KINDS of alumina hydrate?
I only wonder because what I use has never failed me. I've purposely tried it on all sorts of different clay bodies, even stoneware, and it just works. I proved it at Uncle Phil's and at my workshop in Dunedin.
I don't see how it could not work, and in the end I think it all comes down to how exact of a fit you achieve between the foot ring of a piece and the pedestal. If it's tight and perfect, it just works.
It's the only variable I can think of, therefore, maybe there are kinds of alumina hydrate that work better than others?
Or maybe some alumina hydrate is not really alumina hydrate? Like a mislabeled bag, that is really some sort of flux?
EPK is EPK is EPK. It is one of the most reliable and consistent materials in all of ceramics. It's primary application is for use in the spark plug industry, and it maintains high purity and standards of consistency.
Oh well. Back to the two string guitar. I'm writing a song regaling the differences between jam, jelly, and preserves. The differences are subtle, but in the end make all the difference.
Koz
|
|
gczop
Full Member
Posts: 202
|
Post by gczop on May 7, 2016 8:27:53 GMT -6
|
|
timhanrahan
New Member
Still growing crystals!
Posts: 22
|
Post by timhanrahan on May 30, 2016 11:54:27 GMT -6
I have NOT had good luck with EPK. I have been happy with Alumina and wood glue. As I often re-use catchers, after grinding excess glaze to "eyeball flatness", and get a little leakage (not limited to pottery), I have been using a tip from a local stoneware potter of painting the bottoms of my pots with a mixture of Karo syrup, Alumina and food coloring (helps to visually ensure coverage). Once "painted" I just attach pots to the pedestals with the alumina and wood glue. Pots come off real easy and any "leak" damage is minimized.
The Karo syrup has a little sweeter taste than the Elmer's, but be aware that the food coloring on your lips is a dead giveaway that you have been licking the bowl!!
|
|
?
