Painting Marine Engines

[sparau]

Hello,

As a noob with some car mechanical background I keep looking at older boats and seeing the engines painted as a whole, screws, wiring, rubber pipes etc.

Generally I would consider this to be bad practice as AFAIK the paint can affect components in a negative way.

eg:

• rubber components can be degraded or hardened by paint
• screws (especially phillips head) can be a nightmare to avoid stripping even using an impact driver
• threads, nuts
• wiring, any connectors could be dodgy after removal and refitting, depending whether paint got stuck in faces.
• etc

Now I assume this is done in part to try and minimise corrosion, sometimes due to complete laziness.

What is good practice in a marine environment?

Apologies if this has been covered, I searched this sub forum without joy.

For instance, the image below of a boat for sale has had a good random spray job, you can see they have managed to paint inside the alternator.

[gamayun]

Yuk. At least you'd know which hoses have been replaced or not. I had a lot of rust on my engine when I bought it. It is good to de-rust it and re-paint so you can see if there is new leakage from anything. I replaced all the belts after I did the painting and took most of the components off so the end result is much better than this. Used "Yanmar gray" but have heard of people painting their engines all colors under the rainbow and sometimes rainbow-colored, as well...

[Tim R.]

This is very common and I believe still done on new engines. I would assume it is a money saving technique to paint the parts of an engine without having to mask. If the hoses and wires were not connected they would have to mask.

[sparau]

Originally Posted by gamayun

Yuk. At least you'd know which hoses have been replaced or not.

I had thought it gives a fair indication of maintenance schedules or problem areas worked on often.

[sparau]

Originally Posted by Tim R.

This is very common and I believe still done on new engines. I would assume it is a money saving technique to paint the parts of an engine without having to mask. If the hoses and wires were not connected they would have to mask.

Google images does show some new Yanmars with even some flexible hoses sprayed, mostly not though. Perhaps it isn't quite as crappy as I thought.

[a64pilot]

Caterpillar and others do it as well

[Cheechako]

pretty common, although I havent noticed paint inside an alternator before.

[goboatingnow]

Originally Posted by sparau

Hello,



As a noob with some car mechanical background I keep looking at older boats and seeing the engines painted as a whole, screws, wiring, rubber pipes etc.



Generally I would consider this to be bad practice as AFAIK the paint can affect components in a negative way.



eg:

• rubber components can be degraded or hardened by paint
  
• screws (especially phillips head) can be a nightmare to avoid stripping even using an impact driver
  
• threads, nuts
  
• wiring, any connectors could be dodgy after removal and refitting, depending whether paint got stuck in faces.
  
• etc
  

Now I assume this is done in part to try and minimise corrosion, sometimes due to complete laziness.



What is good practice in a marine environment?



Apologies if this has been covered, I searched this sub forum without joy.



For instance, the image below of a boat for sale has had a good random spray job, you can see they have managed to paint inside the alternator.

Are car engines even painted at all ?


Dave


Sent from my iPad using Tapatalk

[Reefmagnet]

That is a factory BetaMarine paint job in the picture. My new engine in my boat is also factory blasted with paint. In my younger days I worked for an industrial machinery manufacturer and it was SOP to slather paint on the engines - wires hoses and all on the finished units with a single coat of air dry industrial enamel.

[Nicholson58]

I sure hope Zeehag posts some photos here of her engine paint. Most inspiring.

We build special machinery with lots of hose and pipe. We use aluminum foil to mask. Simple, fast and easy to remove.

[gamayun]

Originally Posted by Nicholson58

I sure hope Zeehag posts some photos here of her engine paint. Most inspiring.

We build special machinery with lots of hose and pipe. We use aluminum foil to mask. Simple, fast and easy to remove.

A very simple and good idea. I love tricks like this and will stow it in memory banks for the future...

[Wonderinlost]

Originally Posted by Nicholson58

I sure hope Zeehag posts some photos here of her engine paint. Most inspiring.

We build special machinery with lots of hose and pipe. We use aluminum foil to mask. Simple, fast and easy to remove.

Thats a great idea with foil. Heck even plastic food wrap if ya have it. Just need to cover it up. : thumbs :

wandering and wondering around with no destionation

[ullar]

Could you guys give some advice on paint and what to use to degrease before painting? For those of us that are new to that business

[endoftheroad]

Zinc chromate?
Ospho?
Prime bare metal?

[Orchidius]

For degreasing anything before painting I use acetone. For painting any (non esthetically important) metal above water I use hammerite, A tip from a shipyard welder. It's extremely durable and easy to work with, can be applied directly to rust should you have no other option and contains a high level of "rust remover" that stops the rust process and protects the metal. No primer needed.