grounding when painting the engine

[Westiculo]

I'm painting my engines this week and finally finished cleaning them.
I took a bunch of parts off (most of the cooling system, among other things) and am going to spray them separately. Do I need to mask the areas where the different parts bolt to the engine block? the only reason I might think these areas should be bare metal on metal would be to make sure they are grounded to the engine for galvanic corrosion. What do you think; am I overthinking it and should just spray away, or should I mask these areas?

Thanks!

 

[Xsbank]

Just spray away but make sure the power is off and you are wearing a respirator.

 

[jleonard]

I would either mask or sand the paint away upon assembly and then touch up accordingly.

 

[siestakey]

when I paint these areas I either mask or put a little oil on them with my finger this makes it easy to remove the paint for grounding

 

[Jetstream]

Mask any cooling system engine component mating areas as you do need an electrical bond between them for your anodes to be effective in combating galvanic corrosion. Its possible that bolting them back on will make some sort of connection but not guaranteed without bonding straps. It's just easier to do it through the mating surfaces.

 

[GregBrannon]

But isn't there a non-conductive gasket sandwiched between the 'mating surfaces?' Don't the bolts, nuts, and washers that hold the mated parts together provide an electrical path?

 

[HopCar]

I would mask any areas where bare metal is exposed when you remove a part. If the manufacturer didn’t paint it maybe you shouldn’t either.
Certainly mask any metal where wires attach such as the ground cable.

 

[Westiculo]

So, ultimately I've decided that anything in the cooling path should be grounded to the engine. The other stuff doesn't seem to matter. This definitely seems to be the case: the secondary fuel filter mount is completely primed and painted; it is not grounded the engine.

 

[diver dave]

So, ultimately I've decided that anything in the cooling path should be grounded to the engine. The other stuff doesn't seem to matter. This definitely seems to be the case: the secondary fuel filter mount is completely primed and painted; it is not grounded the engine.

check the alternator. Usually, they don't supply a NEG cable to the block. They try to send 70Amps across at least one metal to metal surface. I've had voltage drops here before.

The other possible area of issue (that I have seen) is the coolant temperature gauge. The threads need a path to the Batt NEG, one way or the other.

And, almost forgot; the starter motor. Needs .001 Ohm frame to Bat NEG. I would NOT want all that current going thru steel bolt threads. Usually face to face contact with no paint on the block.

Hop car already covered the Batt NEG wire itself. No paint under it!