Coloring Plaster - how?

I am about to start hand carving some rocks using Joe Fugate's method of mixing patching plaster and portland cement. However, I do not want to buy a 50lb sack of portland cement (the smallest available around town) when I only need a teaspoon or so. The portland cement is only used to tone down the stark white of the plaster, so I figure I can use something else to add color. I was thinking plain old acrylics or Woodland Scenics pigments. Will this work or does anyone have any other suggestions?

Thanks, Jamie

 

Hi Jamie,

Try adding dry power tempera paints. You can find them at Hobby Lobby both on line and in the stores

Gary

 

I have used acrylic paint with good results, as well as food coloring. If you use black food coloring, you can vary a gray look that doesn't glow like the plain white plaster. I do it so chips and imperfections, or small missed areas don't show much.. Is that what you are talking about?

 

I just watched another segment of Joe Fugate's scenery DVD where he constructs a gravel road, and unlike the earlier chapter with the rock carving, he uses black powdered tempera paint. This is probably what I will try.

Yes, exactly. This will be a rock cut succeptible to chips when handling derailed cars, etc.

Jamie

 

I've used RIT dye added to dry plaster and Hydrocal with success. RIT comes in lots of colors and is available in grocery stores and drug stores. Make sure you get the DRY kind. It's cheap, because a little bit goes a l-o-n-g way. I found out early on that you just need a tiny bit to give plaster the right tint or color. Add too much and the result is almost black regardless of which color. Plus I got the feeling that too much tended to weaken the plaster, but I may have mixed that batch wrong.

 

Grout/concrete pigment works equally as well and comes in fairly large bottles for $4

 

I would think that any water based paint or dye would work including liquid poster paint. In using a liquid I would first add the water to the selected color to bring it to the required amount of liquid and to avoid making a weakened end product because of too much liquid. Then add the colored water to the plaster and mix as usual.

 

Powdered concrete dye works great! A little bit goes a looooong way. Wear latex gloves and do all possible to keep it off yourself. (excellent weathering product also)

 

This is what I want to know more about. Can you give us the basics?

 

Home Depot has what you need. Get one bottle of Quickrete buff and one of black. Mix a squirt of buff and one drop (!) of black into a gallon container of water until you like the color. Use the colored water to mix your plaster so that you get consistent batches. There are lots of other colorings, but of the ones I've tried this method does not change the hardness of the plaster or the consistency.

 

I never thought of that. I especially like "...does not change the hardness.....", Thanks Tony. :tb-cool:

 

After pondering the replies to this thread for a while, I decided to go with the powdered paint suggestion. I put about three heaping blobs of patching plaster into a plastic cup and shook in some (about 1/2 teaspoon, or as Rachel Ray likes to say, "Just eyeball it") black powdered tempera paint. This yielded a nice medium gray plaster batch. While it dried very light, it is definitely NOT the usual stark bright white. Worked like a charm. I'll post some pictures in the next few days when (if?) I get the carved rock face completed.

Jamie

 

Mark, I'll post some pics here and in my main layout thread when I get the rockwork completed. In the meantime, I highly recommend checking out this link:

TENMILE CREEK SERIES: Part 5: Great looking hand carved rockwork - video download

This is the chapter of the Joe Fugate scenery DVD that I used to do my rocks. Each chapter can be downloaded for about $2 and the whole DVD is less than $20. In fact, my 11-year old daughter watched this chapter tonight and now wants to do the painting and weathering of the rocks, which I am going to get her started on tomorrow. Easy peasy if you watch the vids. Jamie

 

Here is my first rock project completed using patching plaster tinted gray with black paint powder:

Initial Application:



Final Result:



Complete step-by-step instructions of how I did it can be found on my blog:

http://csxdixieline.blogspot.com/2010/11/howto-hand-carved-rocks.html

Thanks for all of the advice; I really wasn't sure how to tint the plaster. Always get great answers on TrainBoard. :thumbs_up:

Jamie