Nicole Alderman

I've been watching more videos about traditional lime plaster. It looks like most of the time, the lime was mixed with other substances like sand, volcanic ash, or ground quartz. The final coating was 50% lime and 50% ground quartz.



This makes me feel good about using a smaller portion of lime in this plaster. It should still calcify the pigments.

This site states that the intonaco (the layer you paint on), "is made with clean and finely sieved river sand and/or crushed white stone mixed (marble dust for example) with well seasoned slaked lime, worked to a creamy consistency (grassello di calce). In this case the proportions of the plaster are 1 part filler to 1 part lime."

So, if the default is 50/50 lime and something else, then doing 1/3rd will probably still result in decent results...I'm hoping.

I thought, "Why not try another test!?" So, this time I did 1/3rd lime and 2/3rds plaster. (1 tbsp lime, 2 tbsp plaster, a little over 1 tbsp water). I also laid it on a little thicker.

It seems that this mixture retains the benefits of lime. The paint and plaster are still shiny, and there isn't frustrating wicking going on. It might have been slightly harder to work with than the 50/50 mixture. It didn't seem to dry too fast, but it might have dried faster than the 50/50 mixture. I was able to finish my painting before it had solidified.

It should be less alkaline (so better for kids), and hopefully will be more durable. I also have a lot more plaster of Paris than I do hydrated lime, so this should help stretch the amount.

We'll see how they all look in the morning. I'm going to try to be good and not mess with them until then.

Hmmm, it's been a few hours. I picked up both frescos to show my husband. He agreed that the 50/50 mixture was far nicer. But, even just holding it gently to show him, the 50/50 mixture cracked. It is thinner than the 100% Plaster of Paris, so that might be why. Or, is it that the lime is still setting?

I wonder what a 25% lime/75% plaster would look and work like?

Here you can see an example of someone else trying to make a fresco in Plaster of Paris. The pigment really doesn't want to apply, and it impressed deeply with each brush stroke:

I'm teaching kids about the ancient Minoans, and thought it would be fun and educational to have them make their own frescos. I have bagged plaster of Paris and hydrated lime on hand. A lot of the instructions online say to just use plaster of Paris. This stuff sets super fast, which kind of defeats the purpose of fresco painting .

With traditional buon fresco, you're painting with pigments on wet lime plaster. As the lime sets, it also sets the pigments in stone, making them last a lot longer. You usually have a few hours paint, so you only apply enough plaster that you can paint in one sitting.

The plaster of Paris sets in like 5 minutes. I also found it was really hard to add paint to--it didn't really absorbed, and it also sometimes wicked the paint along the plaster. Not optimal. But, lime plaster is expensive and very alkaline--not too good for use with kids.

I did a quick google search, and AI told me, "Mixing hydrated lime with Plaster of Paris (gypsum) creates a durable, workable "gauged" lime plaster, often used for smooth interior finishes. A common, strong mix is 50/50 by weight of both ingredients, with water added to reach a cream-like consistency. It sets faster than lime alone" This was actually taken from this permies thread.

I figured I might as well give it a whirl and see how it worked out. I eyeballed a 50/50 mixture and added about half as much water by volume. The resulting mixture was:
(A) Easier to smooth
(B) Took quite a bit longer to set--more like 30 minutes. Perfect for a classroom activity.
(C) Absorbed the pigments a lot nicer--no wicking or running of the paint
(D) A bit more resilient: the 100% plaster of Paris really pushed down when I applied the brush. The lime/gypsum mix was more...elastic?
(E) The colors are shinier! The painting just looks a lot more vibrant. Both my kids thought it looked better than my 100% plaster-of-Paris version.

I'm not sure how durable each one is. They're just applied on burlap, and both are pretty easy to crack. I feel like the 50/50 mixture is currently easier to crack, but it's also thinner and it still feels a bit damp (it's going to take longer to set, I'm sure!)

I'm mostly posting this to document my little experiment. But, if anyone has any ideas or input or experience with these mixtures, I'd love to know more!

Nicole Alderman wrote:I tend to check permies when my baby is nursing/napping in my arms. Sometimes I even get to comment if she really soundly asleep. I try to always find one post a day to give an apple to. And, if I have time to post my own question, I always try to make time to help someone else by answering THEIR question. I don't always succeed, as some days are crazier than others, but I try!

It's crazy to see this post 8 years later. That little baby is 9 years old now! I no longer have nearly as much time to post, let alone work in my garden. I spend a lot time teaching my kids and their peers about history, art, and science. But, I try to come on at least once a week. And, if I find something I think my fellow permies would like, I try to take time to post it here.

The years sure do fly past, and there really is a season for everything. Sometimes we can post more, and sometimes we can't. But, I'll forever be thankful to permies and all I've learned here and the amazing people who've inspired and helped me. I can never repay that, but I can at least post when I can!

My husband brought home a few of them that he found (I think?) in dumpsters.  He's thinking of flattening the metal and using it for roofing on small structures. He hasn't gotten around to trying it yet, though.

My last time flying was back in 2015, so over 10 years ago. My father-in-law paid for us to fly to Idaho for my sister-in-law's wedding. If that hadn't happened, my last time would have been back in 2000....when I was in high school! (We went down to build houses in Mexico). I have never paid for an airplane ticket, and likely never will!

I'm lazy/cheap, and just use powdered grass-fed gelatin as glue. Granted, I've never tried gluing anything big like an instrument with it! I've just glued paper and cloth with it.

I found it worked great for bookbinding (there's picture of my bookbinding process here on permies). I usually just put a some gelatin in water in a little container. I either heat it up on my stove top burner on 2 or 3. Or, I put it on my woodstove. Here's the picture and description from my other post:

I made my own bookbinders glue by adding gelatin to water. It's a very thick mix, something like 2 tbsps of gelatin to 1/4 cup water. I added clove oil to help prevent the gelatin from spoiling

The picture above show the gelatin having "bloomed" in cold water. I haven't heated it up yet. It turns clear when it's fully warmed.

I apply it with a paintbrush. One downside to it is that it cools/sets very quickly, especially compared to store bought glue. There's not as much forgiveness with the gelatin glue. You really want to get your things lined up correctly when you adhere them to each other!

I made my first leather bound book over 5 years ago. The one made with PVA glue and the one made with gelatin glue have both held up equally well.