DIY rotted barn wood props and scenery from pink insulation foam.

Again referencing my first post. I'm currently attending school for theatre design and production in hopes to one day to do set design for movies. Anyways, last semester my school hosted a guest artist by the name of Scott Gerwitz, a very talented painter/theatre artist that works out of Chicago. He taught a painting and texturing workshop for turning generic pink insulation foam into very detailed and realistic rotted barn wood props and scenery pieces. The display piece he made prior to teaching the class and brought in for us to see is here:

Corner piece simulating a dock pillar that had been exposed to weather. 

As you can see its simply textured and painted insulation foam. 

A close up view to show detail.

Want to learn how to do something like this? 

Things you'll need:

1. Rigid pink insulation foam.
2. Box cutter or sharp blade.
3. A metal bristle brush.
4. Jaxsan coating 
5. Wide disposable chip brush.
6. Small amount of water. 
7. Various colors of paint.

The process starts with a block of insulation foam. This pink foam can be found in most home improvement stores and usually comes in 4 x 8 foot sheets. Also, it's not always pink. there are blue, gray, and green varieties as well. I believe the only difference between them (if there is one) is the "R" value which is only important if you are actually using it for it's intended purpose.

As always, it helps to have reference images handy when you make anything. For this project it may help to have pictures of old barn wood to match paint colors and the overall texture of the wood. 

1. After you have cut the foam into the desired shape and size the next step is to carefully take a box cutter or another sharp blade and cut vertical lines down the entire length of the block into the surface of the foam about half an inch down. (it should be mentioned that you are trying to simulate an organic piece of nature, rarely do perfectly parallel vertical lines appear naturally.) With this in mind you may also try offset some of your cuts so that they intersect with previous cuts, something like this:

   

   Example of how to slice into your block if foam. 

   
   
2. After cutting the grooves into the surface of the foam, take your wire bristle brush and rake the surface of the foam on top of the cuts. This will scratch even smaller grooves into the foam and really make it look like a piece of wood. This step may take some time and is quite a work out as you have to push with a certain pressure to do the job. 
3. The next step is just as messy. Now you have to slather on a coat of Jaxsan. This is a water based product that gives structural strength to all sorts of materials. This stuff is gold because the possibilities of what can be done with it are endless. You need to make sure you get it into all of those little cracks and crevices.
4. After you've coated your block in Jaxsan, you need a brush of some kind (make sure you wet it in water before hand) and brush across the board over the Jaxsan layer. This step is to smooth it out. When you are satisfied with the result let it dry for a couple hours. You may also want to coat the ends and sides of your block as well. If you are interested in texturing the sides, use the same process as step 2. the ends can also get textured too. All I did for mine was stipple on some Jaxsan with a chip brush. you should have something that resembles this by the end of this step:

   

   It should look something like this by the end of step 3.

5. Time to paint. For my sample I mixed up a couple values of brown and watered them down quite a bit. Now the trick is simply layering the different colors on top of each other until you get the look you want. Now would be the time to pull out your research images if you have them; as they will go a long way in deciding what colors you need to mix in order to replicate the look you are going for. 
   
   
   

*** A couple words on cleanup. Please don't wash Jaxsan down the drain. Get a pail of water and get as much of the Jaxsan out of the bristles as you can before cleaning them out in the sink. Trust me, you do not want that stuff clogging up your drain pipes. Once the pail of clean up water has settled at the bottom; you can just pour the extra water in the sink and scrape the collected Jaxsan sediment into the trash.