I just bought myself a used es tuning muffler for 60 buck last night.

Just wanted to know do i have to sand it down to paint it with that high black temp stuff?

Or just i spray it right on?

what does that spray can stuff call?

 

I would also like to know this

 

whenever you paint anything, you have to prep the area under it to help it adhere. this is especially true for paint that is subject to getting hit with debris or in the area of heat. both of those conditions are true for this muffler.

assuming there are not loose spots of existing coating, or deep scratches/chips, i'd sand it down with just enough grit paper to dull the surface, maybe 600 grit or something. then hit it with a degreaser, or even 91% alcohol, and paint it in thin coats, leaving enough time for each coat to dry.

 

muffler shop just sprayed my magnaflow muffler with high temp paint, no sanding or primer. still looks fine after almost 3 yrs

 

right, but was it used and/or previously coated with anything? it probably was a new unit that they scuffed, cleaned and sprayed. i believe the OP bought something used that needs to be refinished. regardless, can't hurt to do it right the first time.