Quarter panel and door sound deadener.

I bought this gun from Amazon.com for $15.
[ame="http://www.amazon.com/Astro-Pneumatic-4538-Economy-Undercoat/dp/B003D3N7W4/ref=sr_1_1?ie=UTF8&qid=1387464511&sr=8-1&keywords=UNDERCOAT+GUN"]Astro Pneumatic 4538 Economy Air Undercoat Gun - Amazon.com[/ame]

I can't say yet whether the texture will be as heavy as the original stuff. I'll play around with the pressure and multiple coats until it's a rough as I can get it.

I think the big difference between the original and the replacement will be the spray pattern of the gun. My quarters looked almost like they applied that stuff with a wide trowel like stucco. But I think it was actually a wide fan pattern on the gun. These cheap undercoat guns don't have any fan, they shoot a small circular pattern.

I don't think I'm going to fool anyone. I'd just like the texture to be similar, but even.