What about using natural dyes to "paint" cob

Hi all; Normally most of my posting is over at the rocket stove forum. Recently I made a personal discovery about cob. Last season when I cobbed the barrel on my rmh I discovered that if I added red concrete dye to my cob it looked really good when wet...however it was quite pink after drying ! Luckily I needed more cob on the barrel so I added some black concrete dye... turns out that just a little black goes a long way... Luckily ,I needed more cob on the barrel... Careful addition of red & black gave me a nice brick red color on my barrel that I enjoyed all winter. This spring I made improvements on the core of my rocket stove again... requiring a new cob job. My plan was to use the same combo of red & black concrete dye on the final layer of cob. Well vertical cobbing is a slow process, at least for me... while working a layer on I noticed that the area ahead really had a good thickness and didn't need any extra, to bad I still needed a color coat on top SO... I thought hmm.. wonder what happens if I mix dry concrete dye together and add some water ? Turns out this works just fine and I can paint directly onto dry cob!!! WoW that means I could paint my barrel after cob is smooth and thick and make it any color I want , as long as it is red,black or yellow....the only concrete dye colors the HD stores sell. This got me looking online to see if other concrete colors like green & blue were available... yup they sure are.. smallest amount I could find was a pound at a time Yikes , 3 lifetimes worth of dye ! At this point my real discovery happened ( http://www.earthpigments.com/ ) These folks sell all natural dyes , some are minned directly from the earth some are mixed , all are natural. Some even have a clay base! I am fascinated by the possibilities. They sell Mayan pigments with incredible colors, I have 35 gram containers of blue and green on their way now ! I have no idea what I will "paint" on my barrel but I am excited about the whole idea! During further reading I found that you can mix these pigments with a wax less shellac and paint water resistant colors directly on to your project ! I am wondering several things. First, is this all old news to "cob people" ? Is using dyes and pigments common practice? If so is there any heat restrictions with using pigments ? What about using shellac either mixed with or painted over dry pigments ? Can the shellac work with outer barrel temps around 200 F ? Is there other products that might work better ? What about linseed oil ? I'm sure that I'm not the first person to stumble across this, although at the rmh forum i've never heard any word of doing this. Is there more information or guidance that I need before proceeding ?

Hi Thomas...welcome to the world of "natural pigments!!"...

Growing up in a house full of painters (with natural home made paints) I knew how to mix all my colors from primaries before I was 4 years old...

thomas rubino wrote:First, is this all old news to "cob people" ? Is using dyes and pigments common practice?

Some of us...it is very old news......and yes is common practice for many of us...

thomas rubino wrote: If so is there any heat restrictions with using pigments ?

Almost all the mineral base pigments are "heat resistant." The challenge is the binders, and carrying agents...these aren't in most cases. Just water and pigment can do a great deal but needs to be reaplied as it "dusts." Many will also "variegate" depending on degrees of heat.

thomas rubino wrote: What about using shellac either mixed with or painted over dry pigments ?

Thousands of methods for this...not on hot surfaces, they burn off...

thomas rubino wrote:Can the shellac work with outer barrel temps around 200 F ?

No, or not over any significant time period without going through different degrees of oxidation, and change (variegating.) Glazes are the only methods that have the best resistance and these can 'crackle' or chip.

thomas rubino wrote:Is there other products that might work better ? What about linseed oil ?

Flax oil will burn off leaving the pigment behind that dusts, but some of these methods are very interesting...Experimenting is fun. I know of no heat resistant commercial paint that is not highly toxic as are the manufactures.

I'm sure that I'm not the first person to stumble across this, although at the rmh forum i've never heard any word of doing this. Is there more information or guidance that I need before proceeding ?

Here are some more (of many) links in no order of importance that you may enjoy having:

Unearthed Paints

Kremer Pigments

Natural Pigments

Sinopia

Mayan Pigments

Real Milk Paint

Olivetti Organic Finishes

Paints, Stains and Pigments are a world onto themselves...The more you learn the more you will be intrigued by this craft and art form...As well as, demystified by all the hype "paint manufactures" claim about modern paints.

Today still the oldest (5000 plus years) paint (and most durable) has been a tempera paint form in Egypt.

Glad you are enjoy playing with color...

Regards,

j

Jay; Thank you so much for such a prompt and concise response ! This is a fascinating subject, i'm so glad I stumbled onto it. I think the folks over at the rmh forum will be interested in my results as well. I will be interested to see how variegated or changed the colors /shellac become with heat. Hopefully my colors arrive soon and ... we keep having chilly mornings. Now I just need to decide how to start and what exactly I think i'm painting...