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MikeFaul

Member Since 08 Aug 2013
Offline Last Active Today, 08:30 AM
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Topics I've Started

Production Potter Productivity

09 December 2014 - 02:49 PM

I'm working on performance plans for 2015, and was trying to figure out what level of productivity I can expect from my employees. I'll provide some background and if anyone has any insight I would appreciate your comments / input. We can fire 61 mugs in a single bisque / glaze firing. And, I want to fire a glaze every other day. So, I need 61 mugs made, dried, and ready for bisque every other day. When the bisque is complete, I glaze those mugs, and fire glaze the same day. We typically run 3 bisque and 3 glaze, but can run 4 of each during a rush, like now. So I need to move 61 pieces into the kilns every other day, which means I need to have the pieces assembled and drying about 48 hours in advance of bisque.

 

To keep that pace I need to assemble 61 pieces a day (hand builders). Right now I'm at 32 to 40 pieces per day assembled. My wheel potters out pace my hand builders and then switch over to hand building to clear the backlog.

 

Wheel Potter:

 

1. How many cylinders should a potter with about 7 to 10 years in clay be able to throw in an hour?

        Each cylinder uses approximately 2.75 lbs of clay

        No handle attachment

        Throws cylinder on small square bat, moves the bat and form to a shelf

        Fills 12 forms per shelf

        Cart hold 7 shelves

2. Each potter trims his / her own cylinders

        Bottom of cylinder is flat, no foot cut into floor of cylinder

        Lower sidewalls need to trimmed on about 1 out of 5 forms

        Curved foot ring cut into sidewall at foot using rib template

        Trimming generally occurs on day after throwing

        Trimmed forms placed into damp box and transferred to hand building

 

Hand Builder:

 

1.  How many mugs can a hand builder assemble in a hour / day?

        Pulls empty shelf from drying rack and places on bench

        Removes trimmed cylinders from damp box and places on bench

        Extrudes handles

        Shapes extrusions to form using jig / template

        Rolls slabs for tiles in slab roller

        Strikes slabs with die, and cuts tiles used as surface design

        Attaches tile using slip / score technique

        Attaches handle to cylinder using slip / score at upper / lower join

        Cuts triangular thumb rest and attaches to top of handle using slip & score technique

        Inspects work, cleans up crumbs, scratches, dents, canvass marks, etc.

        Places assembled mug on shelf, completes 12, and returns shelf to drying rack

 

This is the process we use today. I understand there are lots of things we can do to improve the process, those suggestions would also be helpful. Yes, we could use a ram press, and we do plan to test one in the first quarter of next year, but right now I have to measure this process and need to know what is reasonable productivity?

 

The potters currently throw between 5 and 15 cylinders per hour when throwing and trim at about twice that rate. My feeling is this is low, but I don't know if that's a reasonable belief, and what is a reasonable expectation of performance?

 

The hand builders assemble from 3 to 5 mugs per hour. My feeling is this is very low, but again... Typically 2 or 3 mugs per hour is achieved when multiple tiles have to be attached to the mug. A rate of 4 or 5 mugs per hour is achieved when only a single tile is attached to the mug. Again, I lack experience in a multi-potter production environment and so I don't know if my thinking is accurate or in line with industry norms. 

 

Hand builders perform extrusion tasks, slab rolling, and tile making tasks separate from assembly tasks. 

 

Each position has studio maintenance responsibilities which affect daily production, but not hourly. Maintenance is generally conducted at end of shift and involves cleaning assigned work areas and common areas as part of ongoing dust abatement efforts. All up surfaces are wiped down, filters changed, floors mopped, HEPA vac, etc.

 

 

Your insights would be most helpful...


Unvented Kiln

19 December 2013 - 09:40 AM

So, I'm loading our glaze kiln (Skutt 1231 PK) 31 inches tall, 28 wide, 11.5 cubic foot firing chamber. And the kiln slides on the floor. Now it's on casters, but the casters are suppose to be locked down, and even if they aren't the Envirovent coupler is spring loaded and should drag on the floor... Weird!?!

 

So, I get down on the floor to inspect this oddity, and find... what do I find? The Envirovent coupler is disconnected, not engaged, laying on it's side far away from the vent holes in the floor of the kiln. Meaning we have been firing our kilns unvented. How long? Unknown. Did I say Kilns? Well, me rolls over to inspect Meshach (Our glaze kiln is called Shadrach). Meshach, who does most of our bisque firings is... What's this? Disconnected as well?!? I have no idea how the couplers became disconnected as they are spring loaded and the spring is fairly hefty.

 

So, this means both glaze and bisque have been fired unvented! What are the implications of unvented firing? How might an unvented firing manifest its self in glaze faults? We've been having a series of faults, and now I'm wondering if I might have found the problem...

 

Blistering?

Running?

Color Distortion?

Orange Peel?

 

Your thoughts, other than... Go post this in the thread on "It's OK to make mistakes!" :-)

 

 

Merry Christmas!

 

Mike


Test Kilns

14 December 2013 - 06:58 AM

I'm looking at test kilns to test glazes, clays, and firing schedules. Our production kilns are Skutt 1231 PK Single Phase kilns... We fire to ^6, producing functional wares. What sort of features, volume, size, mobility (we are tight on space), element upgrades, would you suggest we consider? Also, it seems like we should stick with Skutt as the production kilns are of the same make (is this a valid assumption?) last our enviro vent system is maxed out with the two 1231's.

Is it wise to swap out the venting from the 1231 to the new test kiln or is this wrought with peril? Should we purchase a new venting system? Can we run a hose out the window, or do we need to run duct throughout the wall? One of my potters seems to think there no need to actively vent a test kiln, passive is fine, but this would vent into the primary workspace.

Your expertise and thoughts would be most helpful...