Just got my new manifolds and risers today and getting ready to install. All the gasket surfaces are painted and the company I bought from said they go on as such. I spoke with a merc rep who said the same. I'm confused though because every video I've seen they have sanded down the gasket surface to bare metal. My manual is a little vague but says to "clean the mating surface". So painted or no?
Painted gasket surface
- Thread starter Shaun77
- Start date
Bt Doctur
Well-Known Member
A clean surface always works best. Get a flat fine cut file and hit the surfaces to make sure there actually flat.
Air O'Nautical
Well-Known Member
- Feb 5, 2008
- 2,316
- Boat Info
- 1995 400EC. Raymarine E80, Tridata, 4kw dome, Garmin 943
- Engines
- 2013 7.4L Mercruiser Blue water.
Hurth straight shaft 630's,
Westerbeke 7.0 BCG
Check with a flat edge like a steel ruler to ensure there's no raised burrs then, use the correct OEM gaskets (even if your using aftermarket manifolds) and install with the factory paint. If you scrape the paint off they'll start to rust and compromise the mating surface.
Shaun, you're thinking too much. :smt001 You're putting more credence in what you see online, by who knows who, than you are the manufacturer of the manifolds and Mercury. Would you rather trust some Joe Schmoe on the "always truthful" internet or the people that made it?
For what it's worth, this Joe Schmoe agrees with the above posts.
For what it's worth, this Joe Schmoe agrees with the above posts.
Xplicitlnck
Well-Known Member
I asked the same question 2 years ago. I went ahead and listened and sanded down the surface. I am very sorry I did. Within 2 weeks of installing I had rust stains down each joint on the outside of the manifolds. As stated below removing the paint causes rust abd compromises. Looking to change those manifolds after only 2 seasons because if the outside looks as such I can't imagine what the inside looks like.
Bob & Sue
Active Member
I would follow the manufacturer's instructions, the one thing I would do is run a tap down all the threaded holes there have been several posts on this subject after they had broke bolts off trying to torque them down to spec. Don't forget to use the correct thread locker , sealer or you'll regret it later ask me how I know.
Bob & Sue
Active Member
You may be lucky to have caught it in time, might be able to just file them flat or have a machine shop take a skim cut off the mating surface if there is no damage to the water jackets. Then paint them with whatever the manufacturer recommends. It would be worth pulling a riser off to inspect them before buying a new set.
Xplicitlnck
Well-Known Member
I buy new gaskets at the end of every season sine I installed them so I can remove inspect and reinstall. I replaced port side last spring and the starboard side last week. Im most likely going to do the port again next spring. I pulled the riser off the side I removed the paint from and looks like the corrosion is only on the ends on the outward side so im pretty sure I'll b good for another season. Just dRives me crazy looking at the rust stains
