Here's a way to take the brand new prop you made with new materials and dirty it up so it looks like it's covered with years of grime. This also works great for everyday items you use in your haunt to help them blend in.
Pictures that compliment the video:
The amp on the left looked like the amp on the right.
The colors used are grays, rusts, green, brown, white and black. The black is straight paint with no drywall compound added. Any acrylic gloss varnish will work to add shiny spots on your prop for that slimy look.
You can make small batches of colored monster mud using those small jars of drywall compound from the hardware store. For very thick monster mud good for thick accents mix a brimming 1/2 cup of paint (5 oz) with the one jar of drywall compound. This is a 5 to 1 ratio. The original paint color will lighten significantly so bear that in mind. The more paint you add, the thinner the mm. Thinner mud is good for more overall coverage like what was used for the medium gray and medium rust in the video. That ratio is about 3 parts drywall compound to 1 part paint. All of these ratios are flexible and you will discover what ratios you like to work with for the effects you are trying to achieve.
For larger batches of colored monster mud, you could get one of the large buckets of drywall compound and divvy it up into 3 or so colors. Get some empty 2 gallon containers from the hardware store to mix and store.
Close up shot of the effect you get after all the colors are applied with a dab of varnish.
These are Czech Hedgehogs (war barriers)
that was made out of new 2x4's.
Trash can Trauma made extra grimy.
My computer controls the haunt and it's right in the room so I gave it a costume
Quick transformers from plastic trash cans.
This was a black amp made moldy-looking. It's the speaker for a prop so this helps blend it into the scene.
Thanks so much for looking at my tutorial