I was looking at a Mecum auction car (F146) https://www.mecum.com/lots/1159513/1967-shelby-gt500-fastback/?aa_id=738919-067 GT500 67412F2U00910 which shows as a beautiful car. When looking at the underside pictures I saw a example of something that may help others from having the same problem. If you look at the exhaust and the discoloring and darkening of the exhaust pipes that is a example is what happens when you use the high heat clear over regular steel exhaust pipe. Sometimes if you use a rust inhibitor product like T9 or the like it will do that too. That dark look is not what a exhaust pipe should look like if in a concours venue but it IS however better then rust.
How would the Rusted Pipe be counted in a concours venue as I have seen some Pipes get the surface rust just from sitting in a Garage.
To minimize the possibility of surface rust forming on exhaust pipes, after they cool down I spray WD40 on a paper towel and wipe them down. (Having a garage with low humidity helps)
Quote from: tesgt350 on December 22, 2025, 06:43:19 AMHow would the Rusted Pipe be counted in a concours venue as I have seen some Pipes get the surface rust just from sitting in a Garage.
It is typically deducted for but it depends on the judge and the amount of rust. I am in the camp that a very slight amount could and would have been on "some" cars at the dealership before delivery to the first owner.
I've had that happen on some NOS exhaust pipes with surface rust that I cleaned off. Thought it might have been from the rust inhibitor I applied to the pipes. It comes off with some work. Aluminized pipes don't do this if I remember right, which is why they're better for cars that are driven.
Quote from: CharlesTurner on December 22, 2025, 11:36:11 AMI've had that happen on some NOS exhaust pipes with surface rust that I cleaned off. Thought it might have been from the rust inhibitor I applied to the pipes. It comes off with some work. Aluminized pipes don't do this if I remember right, which is why they're better for cars that are driven.
Yes I have come to the rust inhibitor as a culprit and have also seen a reaction using the VHT clear coat. Steel wool typically can return the finish.It is a lot of work.