HOW TO LAMINATE COLOR/WHITE SHEETS

Why laminate sheets of colored clay patterns onto plain sheets of clay?

Lamination-#1web

Sometimes potters ...just want the colored clay patterned sheet go further … or, they only want the color on one side …or, want to make a vessel water tight by lining it with solid clay.

There are many reasons but one problem I get asked about often … because it crops up constantly … is cracking.

 Look at the sheets above and think about what you are doing when you join them. You are asking a perfectly white sheet of clay to shrink at the same rate as that patterned piece that has color, slips and thousands of joining points. Not going to happen without a bit of help.

So, here is a good way to get them to play nicely together.

Roll out both sheets then let them rest on a damp towel under plastic for at least an hour or two. This gives them both time to shrink back a bit at their own pace and to reach a matching humidity. You will have to learn to judge how long to leave them by touch and experience.

If one sheet is much dryer or wetter then wait until they are both the same. They do not have to be the same depth or width but waiting until they match in humidity and shrinkage will pay off in the long run.    

LAM-same-size-webLAM-contact-webLAM-#4-roll-web

Gently place one piece on the other without stretching either piece … you might need a very light spritz of water but not too much. Gently roll over the piece to make sure you don’t have any air bubbles.

After this I generally set the joined pieces aside for a few minutes … once again under plastic on a damp towel.

LAM-5-under-plastic

You might think this is 'over kill' on the babying and waiting, but it is not. You have put in so much work on this piece to get it to this point that waiting a bit for the clay to rest is going to pay off in happy results.

Here is another group of laminating process shots sent to me by Erika Sanger, a student in one of my workshops.

Placing-slices

I am slicing the canes, creating a pattern and carefully patting them down. Then I gently roll them together making sure to only press DOWN, not stretching the pattern.

Patting-down-cane-slices

I let this piece rest on a damp towel beside the matching piece of plain white clay for at least one hour … time to let them shrink back a bit and match up in moisture levels. Then carefully place one on the other.

smoothing-down-laminate

ROLL DOWN … do not stretch if you want the accurate pattern. If you want something a bit wilder, let the two joined pieces rest a bit, then you can roll them to make whatever kind of design you want. 

slabinbowl

Shape and gently press into whatever form you are using. Remember, if you use a hump mold you have to be very careful to get it off before it cracks in drying. For a slump mold you need to test its mobility to make sure it is not sticking to the sides. It will crack wherever it sticks.

PROBLEMS? Check out the Troubleshooting area

Copyright © Chris Campbell Pottery, LLC  chris@ccpottery.com