Paint Motor Mounts

Dec 5, 2013
17
Hunter 33 Cape Coral
My Yanmar mechanic suggest that I paint the motor mounts on a 3ym30. I should of asked for some specifics but I didn't. Any tips ?

Thanks and I wish you all a Merry Christmas !
 
Jan 4, 2006
7,440
Hunter 310 West Vancouver, B.C.
My Yanmar mechanic suggest that I paint the motor mounts on a 3ym30.
But why :confused:.

They're not the first thing one sees when boarding. Did he give you at least a thought, preference, wish, hope, longing, or desire why he thinks they should be painted ?

If it's for corrosion protection, the most important item would be eliminating the source of moisture which is causing the problem.

As far as painting the mounts (if they corroded), they are convoluted little buggers and unless you can remove all of the corrosion products, there's a chance painting may make the problem worse by sealing in moisture and salt.

Assuming the problem is corrosion, I'd suggest:

1. Eliminate the source of moisture.
2. Clean the metal surfaces as well as possible using water.
3. Leave them clean and dry. If you spray them with any type of petroleum based, penetrating surface protectant, you may damage the rubber dampers.

If you can post a picture of the mounts here, we may be able to get a consensus as whether to clean or replace.

Good luck with this and the Best of the Season to you and yours.
 
May 24, 2004
7,202
CC 30 South Florida
I also question the recommendation, if you use an oil based spray paint it can deteriorate the rubber that cushions the engine movement and vibrations. The recommendation may have been for cosmetic reasons as by the time rust would damage a motor mount it would have likely wore out. There is a product out there that neutralizes rust and can later be painted over. Use a brush so as not to paint the rubber parts. Do look for the source of the moisture as an 8 year old boat should not be having engine rust problems.
 
Oct 17, 2011
2,809
Ericson 29 Southport..
The last set I did, I had the little Yanmar out anyway, so of COURSE all the liners, pans, beds, whatever were cleaned and painted. (If someone wanted me to drop an engine back in a 'greasy hole', they've hired the wrong guy to begin with). And while I generally leave these tasks to the owner, there haven't been but a couple that were actually willing to pay my rate to clean an engine sump, the mounts in my opinion ARE my problem. Anyway, they looked fine structurally, so I throw 'em in the glass cabinet and take it all off. You could stand there and hold the nozzle on the rubber all day long and it won't hurt them, it's rubber, and merely bounces the glass/sand back off. Primed them and painted them with the same Yanmar paint that originally goes on the block. The paint obviously is not a give-away, it is after all MARINE paint, so it must be outrageous in price. (I just gagged a little there, sorry). But it looks like the day it was repowered. Beautiful. And if anybody else looks in there, they instantly know this is a tight ship, and not some neglected rust bucket. Which is exactly the opinion I form about the boat, AND its owner at a glance.

And if nobody else sees it, YOU know they look good or bad, and to me that's all that matters anyway.

And as caustic as this is going to sound, if I get a call to work on some greasy, or rusty relic, I have an adjustable rate that will reflect this. Whether you mechanic tells you this or not, I gather MOST mechanics worth their weight does the same.

It's just paint. Twenty bucks. Show some grace. We are not after all power-boaters. That's the kind of crap they do. And why it's twice as expensive if I have to touch it..
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
Painting

I did paint my motor mounts with rustolium
To stop rust from a leaky pump
 
Oct 17, 2011
2,809
Ericson 29 Southport..
Rustoleum would work fine, as would most finer quality spray bombs. It may not prolong the life of the mount, but the reality is, it probably will. The factory mounts on most engines are painted. It would take eons for surface paint to corrupt rubber internally to failure. If that's a bother, tape the rubber. I just used the Yanmar paint because I had it anyway doing the rebuild, and it was the same color. It really doesn't matter as long as it's clean, and has a little decent paint on them. And I'll betcha five bucks that is exactly what your mechanic was advising you to do anyway. Besides, if the motor is out, or moved, new coupler/shaft whatever, you are going to need those threads clean anyway to align the motor back up. After it has settled, tape the area and shoot some of the same paint on the threads for the rust protection. Do you know why they are rusted? It is because they are CARBON STEEL in a marine environment, and it ALL rusts.

Which is why they are painted..
 
Oct 29, 2005
2,366
Hunter Marine 326 303 Singapore
I took both starboard mounts out, clean up the rust then spray paint them black.
Rust was result of CW pump leaking sea water causing rust to some metal parts.
Rust on engine body, I brush it clean and spray with Metal Ash Grey (very similar to Yanmar colour). Good practise to keep engine & compartment dry and clean.
 
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
I know this is somewhat off-the-beaten-thread, but I've owned 5 boats in the last 40 years. The first thing I looked at when buying a used inboard was the overall condition of the engine. In all cases, if the engine looked good, the boat was otherwise well taken care of.
 
Oct 17, 2011
2,809
Ericson 29 Southport..
Warren, I think this thread may have run its course anyway, as it should, its a motor mount. But in my opinion, you are absolutely correct sir. Sanitation systems aside, as they seem to present their own problems regardless of intent, if yer motors clean, its all clean. Really, not a lot of people would spend their 'spare' time degreasing and painting an engine. However, it is a direct indicator of maintenance. The number one indicator of maintenance. And general care of the boat overall. I'm of the sort when I see a bloke with uncared for shoes, who KNOWS what other little nasty details are neglected.
Sorry for the contention, but it is what it is. Don't think there is a correlation? I wish I were like Maine and took horror shots of some of these nasty derelicts that I see. If there are any exceptions to this observation, it has been lost on me.
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
Clean

It's nice to have a clean motor so to see anything is wrong like anything leaking
but yes it's hard to keep moisture from creating some rust on the metal parts of the motor.
I had a salt water leak some time ago so taking the motor mounts off and cleaning them was just from them getting really bad and once rust comes it doesn't get any better.
If you have time to sail and keep your boat looking really nice than more power to you if not well hoping you are enjoying lots of sailing.
Nick