Under hood Paints - Up Pipe Question

Anthony P

Active Member
#2
The up-pipe from the factory was UNCOATED. It was a bin part, like the turbo heat shields, so nicks, scrapes, etc. were common.

here are pics of an original NOS up-pipe. P1030043.JPG P1030044.JPG
Notice the surface marks and grooves lenghwise from the bender and just the raw stock tubing used.

In 1992, I experimented with different finishes and coatings for the up-pipe. I polished a different NOS up-pipe using fine steel wool and WD40 as a medium.
This is the result. P1030045.JPG P1030046.JPG I was happy with the polished look.

A third up-pipe, a used one, I media blasted using medium glass bead media. It cleaned up nicely but was a matte finish. So I polished that one as well. First on the bufffing wheel using a medium cut compound, then different wheels and jeweler's rouge, then the steel wool and WD-40. The end result was like the second pair of pics.

I don't like the aluminum coating spray paints. To me, it just does not look right. From the factory, only the intake manifold and doghouse were painted. Valve covers were left bare aluminum. I media blasted my valve covers and sprayed them with VHT Hi-Temp Aluminum coating. Didn't like the result, so I glass beaded them again and installed bare.

I tried an aluminum coating on the turbo heat shield. did not like that appearance seen here turbo cover.JPG
So that cover was reserved for experimenting with hi-temp ceramic coatings.

I used a different, like-new turbo cover and did the same steel wool and WD-40 routine as on the polished up-pipe pictured. Turbo heat shield polished_myGN.JPG
In this above pic, the up-pipe installed was the forth experiment. It was media blasted and then coated with a stainless steel coating as an aerosol spray. The product was Stylene, made by Drummond American Corp., now Lawson products. I don't believe Stylene is still available.

Maybe just polishing the up-pipe will yield a good finish for you. At least, you can see what an original looked like and taylor that to your specific taste.

But today, we have powder coating and thin-film ceramic coatings to choose from.

Regarding the radiator support and radiator top plate...

To re-do the radiator support, I'd dismantle the front clip and send that large part for media blasting or chemical-based stripping, then prime and spray. Underhood black is about 80 percent gloss. Eastwood makes an underhood black or have a body shop mix and spray some samples for you. Trying to match the inner fenders may take some trial and error with the percent gloss. Certainly no rattle can off the shelf will match - but Eastwood is close, but the surrounding parts possible have a 30 years old finish.

For the radiator top plate....media blast to strip. if there are surface imperfections like small craters on the front part by the latch, it's a little more work. I would suggest powder coating this top plate. Again about 80 % gloss black. A good coater can build the powder over those surface imperfections so the result is a completely smooth surface. However, you may have to use a direct to metal primer and filler to achieve a smooth part ready for powercoating. discuss with the coater.

If you media blast, prime, and spray with Eastwood underhood black, all the surface imperfections of rust/material removed by media blasting process will just be carried through and highly visible in the finished product. have to use the appropriate filler.
 

Darkstar72

Active Member
#3
Wow!! Now that is a wealth of information I will have to digest slowly.

My up pipe appears to have been painted at some point before I purchased the car so I guess my best bet would be to have it stripped and polished as the original finish will not be coming back. Of course my valve covers were painted already as well so those will stay put until the valve cover gaskets are needed again and then I will decide how to move forward with those.

Once again...thank you so much!
 

Anthony P

Active Member
#4
if the up-pipe was painted with a rattle can (vs a coating like powder or ceramic), it may be worthwhile to strip it yourself using a paint stripper to determine the surface finish. Use any brush-on paint stripper like Kleen-Strip from a local hardware store or home center.

it is not known how the part was initially prepped for painting. was the surface scuffed with 400 grit cloth, then sprayed with self-etching primer or direct to metal primer, then finish coat? maybe it was just cleaned with brake cleaner and color sprayed? in these cases, the chemical stripper would preserve the pipe's surface finish. And then you can choose your next step.

if the pipe was media blasted and painted or had a wire wheel used on it, that would become clear with a chemical stripper.

if you media blast the current finish away, it is no longer possible to view the surface finish of the pipe before in was painted.

if this all makes sense, just trying to take baby steps with the unknown so as to not make more work for yourself by going straight to the media blast cabinet and then having to correct the matte and roughed-up surface from media blasting, even though using glass bead yields a fine finish.

side note: in my engine bay pic, the alternator was disassembled and the case was cleaned with glass bead. the alt. fan was media blasted and coated with Stylene as the original galvanized finish was showing discoloration. the belt tensioner was media blasted as well and the pulley re-installed. media blasted the accessory bracket as well. just some other examples of cleaned bare aluminum like the factory rather than painting with aluminum spray.

The Goodson rattle can product is a good product. I would use it on the dog house and the intake manifold if the engine was apart. I don't like powdercoating these aluminum parts. the heat cycle to cure the powder changes the physical properties of the aluminum - it becomes softer and does not yield a clean surface when machined or bored. the machinist who does the throttlebody's specifically states that powdercoating should only be done once the machine work is completed. throttlebodys.com

just more ideas to chew on...
 

Darkstar72

Active Member
#5
I ended going a better route with less effort...I just picked up a stock, unmolested up pipe from a member here that was getting rid of his. It looks so much better on the car than the painted one. I still may play around with the painted one to see what it looks like under there just for giggles.

The next item I need to draw my attention to is going to be the carpet on the rear package tray and attempting to refinish the third brake light. Both are just scorched from sun exposure...from claret/maroon to pretty much grey at this point.