How To Make A Damp Box for Clay

Straight forward and complete instructions about how to make a damp box for clay. You can use a damp box for clay to keep clay workable indefinitely. Or you can use it to dry pieces of pottery out slowly. Either way, a damp box is an inexpensive addition to your pottery studio and can last for years.

[@amyharry3071]

I used 4 liters of water to a 5 kg bag of plaster and it came out brilliantly! thank you for this informative video

[@sarajohnson9521]

Ratio reference: 1 gallon of water (4 quarts) requires 8 lbs of DAP Plaster of Paris.

[@fauxte]

Just what I needed! Thank you!

[@bandwilkalviwilk8437]

Even though I knew how to make the plaster I got loads of great tips!

[@David-uv7hz]

Really good video - great level of detail and explained clearly. Love it!

[@frankeager]

Thanks for doing this.. Being a high school ceramics teacher I am struggling with making videos and keeping up with the demand I need to do. I am glad I can add a some others peoples ideas to my lessons. Thanks again!

[@ThePotteryWheel]

Hi Frank, I'm glad it was useful :)

[@TinyChickPottery]

Great project idea! Thank you.

[@ThePotteryWheel]

Thanks Tiny Chick!

[@bikemadcarl]

Great video. Thanks for sharing ! Please-Please, Do more of these. :-)

[@ThePotteryWheel]

Thanks Carl, I definitely will :)

[@skullservant7340]

I just tried making one of these with builders plaster lol I sure hope it works

[@ThePotteryWheel]

I don't see why not Chris, good luck :)

[@BluecatOSD]

Hello from Portugal. Really good video, thanks. Do more of these. Love it. 😍

[@amyharry3071]

hi! I am in Portugal also. Are you buying gesso de pó for the plaster material? I thought I would try Leroy Merlin.

[@BluecatOSD]

@@amyharry3071 Hoo, how cool, where are you in Portugal? I'm in the Castelo Branco area, close to Serra da Estrela. Yes, I buy from Leroy Merlin. kisses

[@amyharry3071]

I am 20 mins south of Nazaré, in Serra do Bouro. Obrigada por a sua resposta

[@BluecatOSD]

@@amyharry3071 welcome and may you be happy in portugal. kisses.

[@julialapeze6470]

Curious - what's the purpose of adding the petroleum jelly? Can't you just pour the plaster and leave it in the box? Why take it out at all if you're only going to replace it and spritz it?

[@ThePotteryWheel]

Hi Julia, thanks for your message. Yes, you can just leave the plaster in, but I like to give it a rub down to get rid of any loose bits of plaster. If the plaster gets into your clay it can cause problems when you fire. If it looks perfectly smooth, then you might not need to rub it down. Hope that helps..

[@saragomez732]

What stage of dryness does the clay stay at? Leather hard or softer?

[@juliechamberlain6703]

What kind of plaster?
Do you let the plaster cure and for how long?

[@polyphonicart]

Hi Lesley- if my lid isn't air-tight (moves a little when closed) do you have any suggestions as to how to make it airtight? Also, what size is your bin? The link shows a larger bin and mine are 24"Lx16"Wx13.25" and I want to be sure that I have a large enough slab. Or I have a 32Qt size, too. Also, where should the damp box be stored (Dim light, above 50*F, etc)? Thanks! Lucy

[@melissalosos]

I have the same plastic box, do you know how much plaster you used? It looked like you had two 2.5lb bags, and used only part of the second one... is that right or did it take more than what I saw on the video? By the way, thank you, loved the video, you make it seem do-able :-)

[@ThePotteryWheel]

Hi Melissa, I had two bags 2.5 kg bags. 2.5 kg is about 5.5lbs. I used about 4 kgs for this box. It's definitely good to have enough to spare. If the mixture is too thin, then the plaster won't be strong enough and will crumble. So, I'd say get two 2.5 kg / 5.5 lb bags. And you should be fine. Thanks for your comments!

[@MEM2022]

The Pottery Wheel good to know

[@serenedipity8606]

Hi, thank you for the tutorial ! I got through the process, but now i find that the plaster doesn’t get dust free... i tried to clean it but i feel like it crumbles on the surface... i definitely used enough plaster, what did i do wrong? I tried to clean it with a damp cotton fabric. Should it be just dry ?

[@ThePotteryWheel]

How long did you leave it to dry? Plaster says soft and a bit cheesy for quite a while. It should be dry and hard after a week.

[@serenedipity8606]

Thank you, i didn’t know that. I will wait for a couple of days and check if i can wipe it off later... I will report to you how it turned out. Thanks for the advice! I appreciate it ! ☺️

[@ThePotteryWheel]

@@serenedipity8606 great, yes, let me know :)

[@MEM2022]

Can i use plaster of paris or it has to be pottery plaster?

[@ThePotteryWheel]

I use plaster of paris and it's fine

[@emilyhandy7476]

Can you use coconut oil instead of Vaseline?

[@ThePotteryWheel]

I think it would be fine to use coconut oil

[@lorriewardell6484]

It might get moldy if you use something organic

[@ThePotteryWheel]

@@lorriewardell6484 good point..

[@victorianilsen763]

I should have watched this 1st...