Coats Four And Five Plus Pizza

Well the plan was to whitewash on Monday with coat number 4. Yeah that didn't happen. Just too many things to do and more rain. So by Thursday I finally got a chance to put on coat 4 and followed up on Friday with coat 5.

As you can see in the picture above the whitewash is really gotten brighter and evened out. I really wanted the last coasts on so if I had to make any repairs after using the oven on Saturday I could. Saturday we had some family here plus we invited some friends out to make pizzas.

This oven cooks pizza amazingly well! We make up a very large batch of pizza dough and then cut it down into dough balls for each person with sometimes a few extra and a large pot of pizza sauce. We split up the toppings so everybody brings a few.  This way there is plenty for everyone and everyone can make their own pizza.

In the picture above you'll notice the darkening around the door and chimney. There is actually an active fire in the oven when this was taken. I think the smoke staining adds character to the oven. I like to fire the oven between 1 and 2 hours before I'm going to cook pizza in it. The extra time allows for the heat to be absorbed and radiated evenly. I also wanted the oven to be warmed so any moisture left in the outer layers or in the thermal layer was evaporated away. Amazingly after this oven was fired for 10 hours the outside was just finally getting warm. It stayed cool to the touch during the entire pizza cooking. I kept checking about 10 hours later the top and upper portion of the dome was getting warm. The lower portions of the dome and the base were still cool o the touch.

I want to mention that the edges of the counter did get some damage from the rain. It seems that the water lifted up the whitewash where the water drained. The lime wasn't fully cured I think so was able to lift small sections. I applied new whitewash and smoothed it down with my fingers. I also applied more boiled linseed oil to the counter grout and this time I also added it to the edges of the counter. I am trying this to prevent any further damage on the edges. I'm still using mineral spirits to thin out the boiled linseed oil. I think I'll add one more coat of the thinned out linseed oil before I apply a top coat of just the straight linseed oil.

I want to say a word about cracks in the dome. As the oven was heated some expansion cracks appeared on the outside of the oven. My plan is to warm up the oven again and use some lime putty to fill the cracks. The reason I decided to use the lime putty was so it would become part of the outer skin and be able to bond to both the cob plaster and the whitewash. The bonus here is that it will also lend itself to making crack repair easier in time as lime turns to limestone the calcium carbonate crystals will grow and can even self repair small cracks.

I also waned to make a note about the whitewash mix that I used. For the first 3 coats I used a 5 gallon bucket of water mixed with 2 large coffee cans of lime putty. This made for a very thin and penetrating whitewash. The last 2 coats I cut the water in half. So I only used half of a five gallon bucket of water but, the same amount of lime putty. This seems to work very well since the first coats penetrated well and the last 2 coats helped to even everything out and provide a good thick skin of lime. I'll probably have to apply a few more coats after filling all of the expansion cracks.

Coat Number Three

Well I finally managed to get coat number three of the whitewash on. We had storm after storm roll through and then I spent a few days sick. This really messed with my planned wait time of three days. So I was able to get the third coat on yesterday.

Before I whitewashed the oven again I inspected it. I found some damage to the whitewash skin. I had a tarp covering the oven in hopes of protecting the new whitewash when the storms were coming in. It turns out that the wind whipping the tarp against the oven was what had done the damage. The damage was visible due to the whitewash being flaked or scratched off to exposed the adobe beneath.

While applying the whitewash I made sure to paint on several coats to the damaged areas. I applied a full coat including on the grout of the bricks and around the bricks and hinges. I noticed that the fresh whitewash when applied is still being absorbed into the adobe. When applied you can still see the blues and browns appear in the areas where the adobe is still absorbing and it stays white where there is no absorption.

After the coat dried I could see the white begin to even out but, there is still some areas that will need more. I'm planning to add another coat tomorrow to thicken the skin and continue to even out the coat.

One quick note here about applying these coasts of whitewash. I keep these coats thin so that if any of the whitewash can be absorbed it is. I have worked with many different types of coating and in almost all cases the end product of multiple thin coats is stronger than one or two thick coats. I know it takes longer this way but, in the end this provides the best finish possible.

More About Whitewash

My original plan was to apply one coat of whitewash per day for four or five days but, I thought about it and double checked some of my references and decided to wait a few days between each coat. This will allow the calcium carbonate crystals time to begin forming and make for a solid waterproof surface.

I should also make mention of why I chose to use such a basic whitewash mix. Most recipes call for the addition salt, flour paste, milk or glue. I chose not to use any of these for the following reasons. Salt will slowly dissolve the sand, stone or cement and I didn't want to deal with that. The flour paste needs the salt to keep from molding and since I didn't want to use the salt then the flour paste was out. The milk and glue was a simple choice, I didn't have enough so I decided not to use them. Besides I want the whitewash to be able to accept a color coat when the kitchen is done and if I used the other ingredients the color coat may not adhere well.

Since I decided to wait a few days between coats I decided to work on cleaning up the exposed bricks that I had gotten the whitewash on. I used a fine wire brush and cleaned off the bricks trying not to remove or damage the grout between the bricks. Once I did that I used a small paint brush to repaint the grout between the bricks with the whitewash.

I also spent some time working on the counter. I thinned down some boiled linseed oil with mineral spirits and used the small paint brush to apply the linseed oil to the grout between the tiles. I was able to get three coats on the grout to soak in. I'll add more coats of oil tomorrow. I did have to smooth out the oil that flowed on to the tiles. You can see in the picture below how the counter is shiny and you can see the reflection of the oven in the counter. I'm not sure if it'll be quite that shiny when the oil dries, but it will make the counter waterproof.

Tomorrow I'll check on the progress of the oil curing and add more to the grout. I'll use the thinned down oil a couple more times then switch to straight linseed oil for the last coat or two to get the best finish. I use the thinned out linseed oil first to get better absorption and penetration into the grout.

Also just an after thought about applying the whitewash. Expect it to not be white at all when first applied. For me the where areas where it picked up the clay it turned brown and tan but, in other areas it looked blue, purple and even black. However as you can see in the picture above it dries very white and the second coat got considerably brighter. Even though there is still some spots where the clay tan color comes through I thinks the next coat or two will completely cover them and may even brighten the white more if that's possible.