Rusted surpentine pulleys

[chartersj]

After having my first motor with surpentine pulleys for a couple years now I'm getting tired of them always needing attention. Both years I have had to wire brush/sand/file the groves down and re paint them. The paint wears off quick and then the rust starts. The belt dust makes a big mess in the engine compartent and also cannot be good for the motor when it gets into the throttle body. I boat in salt so that obviously accelerates the rust, but it makes me miss the v belt system on my previous motors. That being said I'm looking into replacing the main pulleys this year. I noticed an aluminum raw water pump pulley on eBay, I know aluminum will oxidize as metal rusts but wondering if that would be better and one less pulley to work on as much if I did replace that one with aluminum?

 

[alldodge]

Not sure aluminum will reduce your issue, maybe trade one off for another.

You cleaning and repainting, but is the metal really clean and is primer being used?
Have you thought about having then chemically or ultrasonic cleaned and then powder coated?

 

[Scott Danforth]

you could take new pulleys and have them nickel plated.

if you go aluminum, you need to get the pulleys hard anodized

 

[chartersj]

Not sure aluminum will reduce your issue, maybe trade one off for another.

You cleaning and repainting, but is the metal really clean and is primer being used?
Have you thought about having then chemically or ultrasonic cleaned and then powder coated?

The first year I didn't prime before I painted, so last winter while I had the motor out I was able to do a better job cleaning and getting rid of all the rust, primed and painted. Thought it would last better then it did, but after a few hours the belt wears the paint off to bare metal. Never thought of powder coating, maybe that would stay better

 

[kenny nunez]

Powder coating will hold up better especially if you start with new pulleys. Also with some research in some Chevrolet performance sites you should be able to get aluminum ones that are Anodized.

 

[Rick Stephens]

I would think hard anodized would wear better than even powder coating. I think the abrasion would be a lot less on a hard coat like anodized aluminum.

 

[kenny nunez]

Hard Anodizing would be the ultimate protection. Any Anodizing shop should be able to perform Mil. Spec Anodizing. I know that the local Anodizer does that.

 

[achris]

Over 500 hours on my engine, and the original factory paint on the pulleys is still in perfect condition. I operate exclusively in salt, and flush the engine after every use. I don't overly baby the engine or get out there with a cloth polishing it every 5 minutes. One thing I do have, is a mostly dry bilge. If you have water in the bilge being flung around, then sure, you'll get rusty pulleys.

A friend bought a 'new' boat 2-1/2 years ago, and it had rusty pulleys on an engine the same age as mine. On the first service, I pulled the pulleys off, brushed them back to bare and primed and painted them, and he fixed the water leaks. I serviced the boat last week (4th time since he's owned it), and the paint's still in perfect condition. He also has a dry bilge...

Another friend has a 4.3LX (with vee belts) and his pulleys are so rusted that it's a wonder they still drive the belts. He's got water leaking into the bilge and doesn't care... The bilge is almost always about 1/2 full of seawater...

I guess there's a pattern here, but I just can't see it

Chris...

 

[chartersj]

I will look into the anodizing, I believe some of mercruisers blue motors come aluminum anodized pulleys.

Over 500 hours on my engine, and the original factory paint on the pulleys is still in perfect condition. I operate exclusively in salt, and flush the engine after every use. I don't overly baby the engine or get out there with a cloth polishing it every 5 minutes. One thing I do have, is a mostly dry bilge. If you have water in the bilge being flung around, then sure, you'll get rusty pulleys.

A friend bought a 'new' boat 2-1/2 years ago, and it had rusty pulleys on an engine the same age as mine. On the first service, I pulled the pulleys off, brushed them back to bare and primed and painted them, and he fixed the water leaks. I serviced the boat last week (4th time since he's owned it), and the paint's still in perfect condition. He also has a dry bilge...

Another friend has a 4.3LX (with vee belts) and his pulleys are so rusted that it's a wonder they still drive the belts. He's got water leaking into the bilge and doesn't care... The bilge is almost always about 1/2 full of seawater...

I guess there's a pattern here, but I just can't see it

Chris...

So there is hope for the steel pulleys then. Maybe the primer I used wasn't any good. I keep a very clean bilge and the only water that ever lays in the bottom is a little bit of fresh from the last time I cleaned/ flushed the boat that wouldn't completely drain from the plug. When i bought the boat the pulleys where rusted bad. So maybe they are just too far gone at this point to bring back.

 

[Scott Danforth]

you have to blast or acid clean the pulleys. simply wire brushing them wont get all the rust.

a tub of oxalic acid would work. so would a 20:1 solution of water:muriatic acid make sure to do a neutralizing rinse.

you can also use a battery charger and use two electrodes for eletrolytic derusting.

 

[chartersj]

you have to blast or acid clean the pulleys. simply wire brushing them wont get all the rust.

a tub of oxalic acid would work. so would a 20:1 solution of water:muriatic acid make sure to do a neutralizing rinse.

you can also use a battery charger and use two electrodes for eletrolytic derusting.

Right on well that's probably my issue then. I will have to look into that electrolytic derusting...never heard of it lol

 

[Rick Stephens]

Might just consider wire brushing and then using a pre-paint rust converter (like Gemplers). Like the acid treatment or electrolysis, a rust converter totally deactivates the rust and changes it into a tough substrate for painting. The only rule is get the layers off so the converter soaks into everything. The one advantage of using the battery method is it moves the rust into solution and gets deeper into the layers and pores than any of the other methods.

 

[Scott Danforth]

oxalic acid treatment - throw in tuperware tub with oxalic acid (mixed as directions call) on Sunday night, pull out Friday night, rinse off with water, rinse off with baking soda / water mix. dry, rinse with lacquer thinner, then get powder coated or plated within a day or two. if longer, hose down with WD-40 until you can get powder coater or plater. then re-rinse with lacquer thinner just prior

muriatic acid treatment - 20 cups water for every 1 cup of muriatic acid. throw in tuperware tub on Wednesday night, pull out Friday night, rinse off with water, rinse off with baking soda / water mix. dry, rinse with lacquer thinner, then get powder coated or plated Saturday morning. if longer, hose down with WD-40 until you can get powder coater or plater. then re-rinse with lacquer thinner just prior

electrolysis method - read the tech tips on stovebolt https://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm

be careful...... it gives off hydrogen


blasting method - toss parts in blast cabinet, use medium aggressive media. rinse with lacquer thinner

Me, I make giant tubs of muriatic acid baths to de-rust hoods, fenders, etc. in cold temps, I use a stock tank heater to keep it warm. small metal and aluminum parts go in an oxalic acid bath

i used to use POR 15, however they changed ownership (and the chemical make-up) about 11-12 years ago, so its no longer worth a darn. I now use the local plater, or a 2-part epoxy

 

[chartersj]

Thanks everyone that's a lot of great info. Clearly my prep work was not up to par. Also rattle can paint probably isn't up to the task as well. I don't have any close by powder coating shops, I like the idea of using a 2 part epoxy paint but have never used it. Is it similar to outdrive paint?

 

[achris]

2 pack paint. Hardener and base. Mix in the required proportions, pour into spray gun pot, spray... Clean up with recommended solvent.

I used a 2 pack black on my new (from the GM factory, not Mercury!) sump. Never sprayed or used 2 pack before. That was about 7 years ago. Looked under the engine the other day, and it's still looking as good as the day I sprayed it.

Chris........

 

[scoflaw]

If it has been rusting long enough the pully ridges can be knife like and eat belts. If they're that far gone toss them.

 

[Rick Stephens]

Thanks everyone that's a lot of great info. Clearly my prep work was not up to par. Also rattle can paint probably isn't up to the task as well. I don't have any close by powder coating shops, I like the idea of using a 2 part epoxy paint but have never used it. Is it similar to outdrive paint?

I owned a body/paint shop 40 years ago and everything was 2 part paints then. The only way to gain hardness and resistance to corrosion and weather is with something a lot better than rattle can. Today's paints are absolutely amazing and much better than what was around 40 years ago. You can walk into a NAPA store and get a run of the mill 'commercial' paint that will last many times rattle can paint. Read 'commercial' as cheap crap. The good stuff, like CrossFire, which is a 2 part epoxy paint, will get you incredible durability compared to rattle can. I used that to paint my outdrive several years ago, still looks new.

Spraying an epoxy means you need an air compressor and a spray gun. It goes on better than rattle cans and following directions pays rewards in results.

 

[chartersj]

I have decided to try the rust converter method. I would have to pull the engine again to remove the pulleys which isn't a big job but would rather avoid it for now. I would like to use a 2 part paint but I don't have a spray gun. What would be best brush on primer and paint for a high build and durability?

 

[Rick Stephens]

I don't know if there is one. Would go one rough and wear horribly. Others might have a thought, but I wouldn't even consider this a candidate for a paint on solution.

 

[Mad Props]

You might also be able to clean them up and find a local chrome shop (they typically do truck parts, wheels, etc...) They would probably throw those in for a pretty good price. Chrome plating is very hard and wear resistant so it should be a good option.