Using graphite spray on exhaust manifolds
 

I was wondering if anyone has tried using graphite spray on their exhaust manifolds? I saw it used on a couple of youtube videos, thought it looked good so I gave it a try and really liked the results. It's a couple of shades darker than as cast - cast iron but looks good enough for me. Not to mention there's no need to bead or sand blast them before using. Just wire brush, clean with Brake Cleaner, spray with Graphite spray lube, let dry & wipe down. (I used PB Blaster Graphite Dry Lubricant $6.58 at Home Depot) one 5.5 oz can easily did both exhaust manifolds. My motor is still out of the car so I can't say how well it will hold up.

Off the car - wire brush, clean & spray, let dry wipe down & install
https://www.youtube.com/watch?v=5nt75-4bzI8&t=48s

New cast iron manifold castings
https://www.youtube.com/watch?v=Qqh22Pafzag&t=344s

Old manifolds done on the car.
https://www.youtube.com/watch?v=hHXm5Hxijw4&t=189s

My manifolds I did - the as cast Master Cylinder is there for color comparison. Any comments good & bad are appreciated. Be honest - you can't hurt my feelings - I don't have any.

I like it. Nice job!

I used something similar about 15 yrs ago.....was a paste as I recall.

I don't know how well it will protect against corrosion long term (probably not great), but it's easy to touch up and I like the look better than paint and way better than rusty iron.

Kind of like the old school method of using wood stove polish, which has graphite as the main ingredient.

The jury’s out until you’ve put some miles on them.

Anything you paint onto exhaust manifolds or headers will look good before you run them

Hopefully they’ll look good after a few years, if not then it’s just some labor to get them off and a small outlay for a different product to get them redone.

I used the paint by brush method with the Eastwood can paint. 2500 miles later, they look as good as day I did them.

That might have been Calyx?

Yes, that sounds like the product. Thank you.

One benefit of using products like graphite/Calyx/stove polish/etc. is that if and when the manifolds start looking scruffy, you can just reapply more. No real preparation is needed.

Which Eastwood product?

It appears Eastwood only has one high temp coating for exhausts these days: https://www.eastwood.com/paints/hi-t...st-paints.html Years ago they had a product with stainless steel in it that left an as cast look. I used it on my car with good results but it's not in their catalog anymore.

I think people have been using "Slip Plate" graphite products for a while now on exhaust manifolds. They make an aerosol and a brush on. I've used it for years on my snow thrower chute. No idea how it holds up on exhaust though.

The makers of POR-15 have the same type of high heat manifold coating too. I used it on turbo exhaust manifolds and wastegate thats lasted for 10+ years. Looks like fresh cast iron.

I just looked since it's been a few years. Yes, it's POR 15. Great stuff.

I used POR 15's exhaust manifold paint(followed all the instructions) and it started flaking off almost immediately. The RA manifolds were brand new at the time.

Strange for that to happen, must have been an issue with the prep or application or maybe a defective can. Never heard of POR high temp flaking off "immediately"... mine & everyone I know of thats used it has lasted for years, mine is at 12-13 years on turbo cast iron manifolds & wastegate with only some light signs of rust stains coming through in a few areas after all that time.

VHT spray can is supposed to be pretty good too, I knew a guy with an olds or buick at the drag strip with the blue VHT paint on headers, he came to the track for 3-4 years and we had a rivalry racing each other, it ran low 11's... the headers looked great every year I saw them, the car was street driven and did lots of runs at the track. I plan to try it when I do a clean up & repaint of the engine in my 78 that has the silver color POR header paint flaking off after about 15 years, easier to clean & mask them off than removing to recoat.

I’ve had both results with POR15 manifold paint.
Twice I did a set of SBC rams horn manifolds. They were sandblasted, handled with rubber gloves, washed with lacquer thinner and painted with a brush. Then left to dry for a couple days. Both times they flaked off and rusted in less than a year.
I also did a set of RARE ram air manifolds with the same procedure except I baked them in an old electric oven. They are holding up great so far 4 years later. They only have about 1000 miles on them now so time will tell.

I wonder if the silver color of the VHT paint that I used and baked in an industrial oven, according to their instructions, was the problem when I used it? My manifolds surface rusted just sitting outside at my painters for a couple of months.

How mine looked after 30k miles and 5 years of daily driver use, my first attempt at using POR-15 manifold paint about 24 years ago.

I did use Metal Prep after bead blasting them to clean and etch the bare metal before brushing on the paint. I didn’t bake them before running them on the engine. The manifolds were brand new.

The silver color VHT on my lakester's zoomies has held up quite well. They still look almost as good as they did new (in the picture).

I can't imagine where I went wrong.. I had great faith that choking my co-workers all day was going to be worth it.

POR and most other high temp paints require a baking procedure to cure properly... cant just let them dry for a few days then expose to full temps. Probably why the SBC manifolds didnt work out compared to the RARE manifolds.

Yeah I'm not sure how you guys are having poor results with POR15 manifold paints or what went wrong but I've used that stuff for decades and just as B-man reports the results have been excellent.

In fact I have that stuff on the RA manifolds on my 70 bird that I daily drive. I don't know how many years it's been now but it's been a bunch with I'm sure thousands and thousands of heat cycles and they still look like the day I installed them.

All I did was glass bead them in the cabinet, blew them off with compressed air and applied POR-15 with a brush. Installed them on the car and run it. In fact that's all I've ever done when using this stuff and never had a bad result.

I also have access to ceramic powder coating and a giant oven that I'm doing on headers which works fantastic and I have a wide variety of colors to choose from. Could technically use it on manifolds as well but the POR15 is so easy to do I haven't found a need. The rough texture of the manifolds allows me to get away with just brushing the stuff on, where the headers really need a nice finish, so they get blasted and sprayed.

My manifolds were brand new and prepped the way POR said to do it, including baking them in the oven. I'm pretty sure the silver stuff was called POR 20. This was in 2013.

Yeah that's just really strange and honestly unheard of around the car circles I'm involved with. Maybe a bad batch of POR, or maybe prep issues?

I've never done anything special to the manifolds when I use it. Just glass bead, brush on, install on car, that's it. Even on old used manifolds the stuff has held up perfectly.

Ive used the POR20 slver header paint too, used a brush and it lays out to look like it was sprayed. did some lower temp heat cycles to cure as per instructions. It looked awesome & held up for about 7-8 years but the car is stored outside in a dry lean-to shed off the back of my garage for winters so its exposed to lots of condensation as the temps get warmer in the spring, the engine & all metal parts will look like a ice cold soda or beer bottle in humid summer temps, so im sure that shortened its life quite a bit. heres a pic of what it looked like a few years after use.

I also mixed some POR manifold grey with the POR20 silver about 50/50 to make a silverish/grey color and used on the up/down pipes on my turbo 301, that looks like the day it was applied 10+ years ago with no signs of failure.

I don't remember the POR 15 instructions saying anything about baking. I just bead blasted, cleaned with lacquer thinner and painted. Just as others have done with great results. My poor experience with VHT paints forced me to try this.

Read all safety warnings and precautions on label before use.

APPLICATION:
Liquid paint directions:

On previously painted surfaces blistered and loose paint must be removed. Sandblasting is the optimum surface preparation. Clean painted and bare metal surfaces with POR-15 Cleaner Degreaser to ensure that the surface is clean, dry, and free from oil, grease, dirt, salts, and any other contaminants. Paint all bare areas with two coats of POR-15 High Temp Coating. Glossy surfaces should be roughened with 320 grit sand paper before recoating. Allow POR-15 High Temp Coating to cure for 24 hours on the surface before temperature is raised above 300°F for full cure.

Dry time: Cures to touch in 4 hours. Second coat can be applied in 24 hours, depending on ambient temperature and humidity. POR-15 High Temp reaches maximum hardness after heat exposure above 300°F (150°C) for 15 minutes and then allowed to cool down.

Clean up: Do not put left-over paint back into can. Clean all equipment immediately after use. At the same time, flush out all fluid lines and carefully clean pressure pots. Use clean POR-15 Solvent only. It is also good practice to periodically clean the spray tip or the fluid tip/air cap combination during the course of the working day or shift.

Aerosol spray directions:

Surface must be clean, dry an free of all oil and other contaminants before painting. Sandblasting is the optimum surface preparation. Protect surrounding areas from spray mist. Must be heat cured at a minimum temperature of 400°F (205°C) for two hours. More than one coat may be required for full hide.

Shake can at least one minute before and occasionally during use.
Spray surface with steady, even strokes at a distance of 8 to 10 inches. Several light coats give a better finish than one heavy coat. For best results, recoat within 1 hour or after 24.
Cleanup: To prevent clogs in spray nozzle, hold can upside down and spray until clear gas appears. Completely empty cans may be recycled or disposed of with regular trash. Dispose of partially empty cans responsibly. DO NOT puncture, incinerate or compact.


https://por15.com/products/high-temp

Are you guys spraying it? Maybe taking the pint can and thinning it down to spray?

Im just trying to find the difference.

I don't do that, I use it straight out of the pint can with a throw away brush. I was never remotely interested in running that stuff through my $800 gun.

Brush on, not spray. I guess since I wasn't using aerosol, that's why my can never mentioned baking it on. It doesn't require that.

I posted the instructions for both brush on & spray aerosol... both say that a curing process is recommended for maximum hardness. The brush on does require that for best results.