Engine repainting advice

[Pnwwannabe]

I am repainting a couple of CAT 3208s to treat some rust. I am cleaning, abrading rust with brass brush and or sandpaper, and applying permatex. Question is on what kind of primer to use. I have read that epoxy based primer which is rated for temp up to 250 or 300F is appropriate. Anyone have advice on what primer works best? And what systems can be used to apply easily in all the nooks and crannies?! Thanks for the benefit of your experience!

 

[lwarden]

I did my Cummins engines a few years ago. Wire brushed the bad areas, treated with Ospho, primed with Rustoleum Rusty Metal Primer for ferrous parts and zinc phosphate for aluminum, both in spray and brush form, cleaned with denatured alcohol and top coated with Rustoleum 2X enamel. I setup a large box fan to pull all the overspray out and masked off everything with plastic as best as possible. Of course use a respirator and other PPE. Some parts like the engine mounts that were really bad were sent out for sand blasting and powdercoating.
It's lasted very well. No need for high temp paint unless you are spraying the turbo out let or right next to the heads on the exhaust manifold.

 

[KnotYet]

It is rare to see someone go to the effort that Iwarden's photos reveal he has!
His results look like factory parts and I'd guess the engines are properly maintained, too.

 

[Fletcher500]

100% agree with KnotYet. Laurence, your work and attention to detail is always impressive.

 

[SIBERNUT]

Work like yours is always impressive. But bringing back a neglected engine like mine, blue tape & a cheap airbrush are my friends.

 

[Duvie]

After proper prep work I am a brush and Rustoleum guy. I don't like using spray. For tight detail areas I break out a 1/4-inch artist brush.

 

[Pnwwannabe]

I did my Cummins engines a few years ago. Wire brushed the bad areas, treated with Ospho, primed with Rustoleum Rusty Metal Primer for ferrous parts and zinc phosphate for aluminum, both in spray and brush form, cleaned with denatured alcohol and top coated with Rustoleum 2X enamel. I setup a large box fan to pull all the overspray out and masked off everything with plastic as best as possible. Of course use a respirator and other PPE. Some parts like the engine mounts that were really bad were sent out for sand blasting and powdercoating.
It's lasted very well. No need for high temp paint unless you are spraying the turbo out let or right next to the heads on the exhaust manifold.

Thanks! Sounds like epoxy primer not necessary although I have read that it seals better. Think I will work with combo of spray and brush. Out of curiosity how did you get the engine mounts out? Did you have a lift for the engine?

 

[Pnwwannabe]

After proper prep work I am a brush and Rustoleum guy. I don't like using spray. For tight detail areas I break out a 1/4-inch artist brush. View attachment 169988

 

[Pnwwannabe]

Thanks Duvie. Think I will do the same with a small brush for some of the hard to reach areas!! Appreciate your response!

 

[lwarden]

Thanks! Sounds like epoxy primer not necessary although I have read that it seals better. Think I will work with combo of spray and brush. Out of curiosity how did you get the engine mounts out? Did you have a lift for the engine?

I made some spare mounts out of some Simpson Strong Tie HD2A hold down brackets from Lowes and bolted them onto the transmission where there were a couple of unused mounting holes.

https://www.lowes.com/pd/Simpson-Strong-Tie-HD2A-Holdown/1091671

This held the engine up about 4" higher while I repainted the rear mounts. Then I use some 3/4 threaded rod and nuts to jack the rear up and pivot on the front mounts so I could get underneath the transmission. I didn't think to take pictures, but you get the idea.

BTW, can't take credit for the prep and paint process, I followed a post from a guy who did engines just like mine in a McKinna 47. His engines came out really nice, I can't remember what site that was on.

 

[scurvydog_pnw]

I am repainting a couple of CAT 3208s to treat some rust. I am cleaning, abrading rust with brass brush and or sandpaper, and applying permatex. Question is on what kind of primer to use. I have read that epoxy based primer which is rated for temp up to 250 or 300F is appropriate. Anyone have advice on what primer works best? And what systems can be used to apply easily in all the nooks and crannies?! Thanks for the benefit of your experience!

Whenever I am painting engines I will use aluminum foil to mask parts. It is quick cheap and works great across complex parts.

 

[RT Firefly]

Greetings,
Prior to the sale of our boat I touched up our Lehmans. I changed all the rubber hosing so it was easy to reach those spots that needed attention (under the rubber hose). Combination of brush and a bit of spray. White valve cover wasn't too bad so I left it as is.

 

[SIBERNUT]

I've been accused of unorthodox methods before.
Id mask off with foil/tape, warm up the engine & let it run while i rattle-canned it. Dries faster & engine gets rid of fumes/overspray vs having it all over boat like using a fan.
Or, buy a cheap air brush.