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perkolator

Member Since 08 Feb 2012
Offline Last Active Feb 18 2017 12:36 PM
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Posts I've Made

In Topic: Building A Hydraulic Extruder

10 February 2017 - 04:59 PM

I agree to buy individual parts and custom fabricate the unit.  We have a large 14" hydraulic extruder in our studio that is a one-off piece of equipment.  If I recall correct, it was built by someone at Univ. of Minnesota.

 

Ours accepts a 16" square die plate, with an approx 14" extrusion limit.  It has a hydraulic cylinder for the main ram, which as control valves for the hydraulic pressure and up/down stroke.  I can stop it during mid-stroke, I can also change the speed during mid-stroke...it also tilts into horizontal position AND has a 2nd ram hidden inside the base to make it taller for extruding longer forms in vertical orientation.  I can try to take some pics, but in my honest opinion this thing has some major design flaws that I would definitely change if I were to build one myself (the issues mainly are due to the capability of going into horizontal position and being able to change vertical height - it just needs some major improvements for safety).  We have the Bailey pneumatic as well, I would likely share some of those design concepts if/when I finally decide to chop into this thing.

 

The original dies we got with our extruder were mainly for extruding slabs/tiles, but we've since made many of our own.  The problem with this is that when you have a LOT of hydraulic pressure + a large diameter die plate, you can very easily snap dies in half (depending on the shape, since certain shapes restrict too much clay and create too much pressure behind it).  Many of the dies with smaller apertures have to be double thick matieral (3/4" plywood) or made of something else, like steel.


In Topic: Which Model Brent Wheel For School Use?

10 February 2017 - 04:34 PM

This is true, it depends on what you use your wheel for and what your personal needs or preferences are.  Technically a 90hp car can achieve highway speeds just like a 300hp car can, but they'd definitely not be the same getting there.

We're not throwing pots, we use the wheel as a tool to make forms used in large scale sculpture...and undergrads destroy everything in their path, so our needs are much different than most other studios...this is why my viewpoint is always skewed toward being overkill with everything  :D


In Topic: Imco Mid-Fire Clay Reviews Wanted

10 February 2017 - 04:23 PM

Have you called them yet and talked with Aaron?

 

I've used many of the IMCO pugged clays over the years, I have no complaints.  Mainly we make our own clay from dry materials (which I get many from IMCO), but many of our students, local schools, local artists, etc buy their clay and seem to like it.  Heck, I was over there one day and saw a pallets of Leslie Ceramics clay bodies, so I guess they're the one who produces some of Toki's pugged clays.

 

I have not used the Starry Night, I think that's a newer clay body of theirs?  I have a 50lb bag of that ilmenite they put in it, I got it from IMCO to test out as a potential grog substitute/filler material.

 

 

My MIL used to teach HS ceramics in Sacramento and she used IMCO clays most of the time vs Laguna or other brand clay from Alpha, since IMCO delivers and Alpha doesn't.  They fired to ^6, with commercial glazes and I didn't really see any issues with vitrification.  From their IMCO stash I've used over the years:  navajo wheel, great white, 50/50 mix, and sculpture 50, IMCO sculpture mix, Elf White, Stoneware #5 and Sculpture 412.


In Topic: Dealing With Overkill Packaging

10 February 2017 - 04:01 PM

perkolator, what about putting some delicate thing inside a plastic bag, taping it closed, thoroughly covered with plastic wrapping and then turning on a can of spray foam insulation into the box, loading the item when there is a good layer in the bottom, filling all the rest with separate bags of the spray foam.  it takes a bit of patience and judgement to stop in time but wouldn't the outcome be the same as the way you get kiln parts without the expensive machine?

I've tried that actually, it didn't work as well as I wanted (it's actually what inspired using inflatable pool tubes)....but I want to try it again since I've seen ways to improve the foam cure - like with a spritz of water/humidity.  The problem I saw was that we used Great Stuff spray foam in a can, which is a single stage cure - much different than the chemical-cure of 2-part foam used in packaging and modern wall insulation

 

This is why I suggested to faculty to buy one of those machines.  Would love to test one out if knew someone who had it.  Cost has gone down and the tech seems to have improved - one major hangup was the short shelf life once you open the containers of foam.  I think nowadays the containers are smaller and shelf life slightly extended - but still, unless you're using it often it may not be worth it.  There's also the question of what to do if it needs return shipping, since the piece was removed from the "foamed in place" packaging.

 

Faculty buy all their own packing materials.  The soft sheet foam comes in a roll approx 2ft diameter, the bubble wrap in a 40" diameter roll, she buys from a local shipper but pretty sure you can get it from uLine or similar.  The rigid white styrafoam sheeting she usually gets from the guy who builds her crates, but I've gone on emergency to local hardware store to buy foam sheet insulation, which is pretty much the same just more expensive.


In Topic: Which Model Brent Wheel For School Use?

09 February 2017 - 05:22 PM

We use Brent CXC....they don't get heavily used since we're not potters in our studio, but they've lasted over 20 years of undergraduate abuse.  Very simple machines to service if any problems with them, usually it's the foot pedal fork that breaks when someone stomps the pedal or drops pedal.

 

I've thrown on a lot of different wheels in high schools around the area, they always seem to have mixed equipment between schools.  I mainly prefer the wheels with a removable splash pan vs the style that's recessed into a molded splash pan.  Go for the highest HP rating you can find, I've had small wheels bog down when centering with only 15-20lbs of clay on it.  

 

My preference would probably go to the Brent since its what I've thrown on the longest.  I was quite fond of my old motorized Lockerbie, but that thing was a beast and took up too much real estate.  The ancient Alpine gear driven wheel I replaced it with years ago will torque off your arm if not paying attention :)  Shimpo's are pretty nice too, quiet.