Painting an engine

[Slinky Spring]

I have taken my 1gm10 out of the boat for the winter to do various jobs(like getting it going!) One of the jobs is to paint it. As it is greasy and rusty in places how should I go about it.
I touched it up a bit last year and some of that is coming off already. Obviously preparation is the key. Any advice?

 

[PilotWolf]

One thing I d say is be careful not to coat any threads in paint... we destroyed a oil pressure switch today trying to replace the ring terminal due to the excessive paint applied by Mercruiser.

W.

 

[dean1973]

clean sand and degrease degrease use old bolts to fill holes then over spray want matter

 

[VicS]

I partly did an engine in a friends boat a few years back.

Thoroughly degreased it. Chipped and scraped off the rust, applied a rust remover, chipped and scrapped some more, applied more rust remover and kept repeating that until I had got rid of all the rust then gave it couple of coats of Hammerite.

Still looked Ok last time I saw it.

 

[tazzle]

Completely degreased engine and bilges with Meguiars Super Degreaser (this stuff is a very strong degreaser), then prepped engine with POR-15 Metal Ready Zinc Phosphate primer and painted with POR-15 rust preventative paint. This stuff is the biz - it really is. Also used it on emergency tiller (the rusty iron bar lying at the back of everyone's lazarette) and even big steel skeg and all other bits of rusty old metal - it really works.

I've got some engine enamel to top coat with but haven't got around to it yet. But engine in grey POR-15 still looks like new.

 

[donm]

My vote goes to Hammerite too. I have done several engines with good results. Thorough degreasing is essential.

 

[rich]

I did my pair in 2004,

 

[roly_voya]

I have degreased engines by using a wet grit blaster (presure washer + grit feed), cost abot £50 in hire charges but did an imaculate jobe in about 1/2 and hour. Obvously you have to very thougholy block all openings and rinse well after but its the only thing that gets old paint out of all the corners.

 

[warrenmarkus1]

Having the same problem last season, I had to rebuild the engine, and took all the bits to my engine reconditioner who was doing the rebore, and they put it in their (acid? and then steam) cleaner that took off all the rubbish (not for brass). A light wire brush only was needed to take off the odd patch of rust/paint. I then painted the parts in an etch primer before assembly. After a light degrease after assembly (and touch up) I sprayed the whole engine in volvo paint - looked like new!!

 

[Wino]

Although it has been suggested using a sand blast machine, do not do it. I have seen 3 engines which have been sandblasted and all subsequently suffered with bearing failure. It appears as if it is impossible to prevent grit getting into engine and oilways. Then grit/sand + oil = grinding paste.
On each occasion the engine was scrapped as it was too expensive to ensure all oilways were completly clean.