In every armor model I have built I have used the same method to give a realistic look to mufflers.

Supplies needed:

• rust and dark brown colored paint colored paint
  
• some kind of fine powder (I use flour)
  
• a disposable dish to mix paint
  
• a cruddy brush
  

Take the rust paint (enough to cover the whole muffler) and dump some into the disposable dish. Take the powder and mix it into the rust colored paint (the amount will depend on how rusty you want the muffler). Mix it until it is thick and goopey. Take your junk brush and spread the mixture over the whole muffler. After it is dry, take a good brush and "half-dry-brush" the muffler by wiping off a lot of the paint, but not as much as you would for regular dry-brushing. Lightly brush the whole muffler until the desired effect is achieved. Next, paint the inside the exhaust tube flat black.

If anyone has any comments, suggestions, or critisizms to improve this process feel free to share

Machu, this seems like a good technique and very simple too. Do you have any pictures of these rusted mufflers you have done?

Not at the moment but I plan on posting some pics soon

Looking forward to seeing them.

Look at the very last picture. The muffler was made using this method.

https://armorama.kitmaker.net/forums/13842&page=1

This is fantastically cheap method (as opposed to rustall etc). I swipe some of the wife's baking soda for it and it works great.....

He is what I do. I take humbrols #113 paint it on when it's tacky I lightly powder it with actual rust from steel wool [ which I made by letting sit in water]. When the muffler and pipes are dry. I take a soft lead pencil and lightly pass a couple of strokes across it. Seems to work for me. (++)




Butch Cassidy Tanks46
Pig #3 Head Armorer
DSB (++)

It looks almost the same technique I'm using with the only difference that I use talcum powder instead of flour...



Ciao

This is the method I used for the exhaust on my Marder III:
First off I painted the exhaust a black/metallic grey color. While this dried, I took some various shades of black, brown, orange, and reddish colored (chalk) pastels. Shaved off a bit (very technical measurement) of each...and mix til it looks good to me.
After mixing the powder, I painted some MM Acryl Flat on the part, then kinda dipped the part in the chalk mixture, let it dry and then coated it with a light coat of Flat again, and before it dries use a clean brush to dust on some more powder. In spite of constant handling, the remaining powder has yet to come off. This pic is the fruit of my labor. Please let me know what you think. (I know I still need to fix the part where the pipe goes into the hull, just noticed that).