Rust removal and controll

The "new" boat's 3208s have a rust problem. The starters and the motor mounts are looking pretty bad. Here and there on the other parts of the engines there are rust pocketss as well. Where do I start? I have read about ospho but have also read about a product called "rustbullet" and how great it is--written by the company but has testimonials by the US Navy also listed. Has anyone heard of that or used it? I guess start with a wire brush, but than what? Thanks

I have used Ospho with excellent results; it turns rust into a hard black fairly inert residue that can be painted. Scrape/wire brush off as much flakey loose rust as possible, degrease, apply Ospho with a brush, leave to dry and paint.

BTW: It's worth checking that you don't have any sea water leaks that might be causing the rust - cooling system/stern glands etc.

Good luck,
Mike

We've used Corroseal with good results.

http://corroseal.com/

Fighterpilot wrote:
The "new" boat's 3208s have a rust problem. The starters and the motor mounts are looking pretty bad. Here and there on the other parts of the engines there are rust pocketss as well. Where do I start? I have read about ospho but have also read about a product called "rustbullet" and how great it is--written by the company but has testimonials by the US Navy also listed. Has anyone heard of that or used it? I guess start with a wire brush, but than what? Thanks

Click to expand...

*I haven't used Rustbullet but have both Corroseal and Ospho. *Corroseal is thicker, and I think I prefer the Ospho. *Both require some rust present to chemically react with so you don't need to do more than remove scale and loose bits. *After fixing the rust with Ospho, prime and paint over the spots. *I use an airbrush since you can put as little or as much paint as you want to and end up with a pretty clean job. *

We have used ospho a lot over the years with good results. The best product we have found is POR 15 which is our preference over any other. With the POR, if you plan to paint, you have a small window to get the paint on before the POR completely sets. If done properly, you won't see rust again in those spots. Chuck

I have some small rust spots which I have sprayed with Corrosion Block or others will Ospho ect work over that?
Steve W

My entire gear box is coated w POR15. It's UV sensitive but who cares in the engine compartment. Por15 sells another product that is an ideal top coat called Chassis Coat and is used for automotive frames. I did my new 275 gallon heating oil tank behind the house w both POR15 and Chassis Coat. You do'nt need to get all the rust off w POR15 *...just the loose stuff. Follow the directions on the can perfectly. There are some unusual handling requirements but the stuff is amazing. Highly recommended.

Ospho and paint will be fine on an engine , but for hull work ,the standard of sandblasting to "water white" (a trade specification) and coating with the usual 5 to 7 coats will give the longest life.

Its the choice of boats like the ESSO MARU , where a single day out of service is huge $$$.

Steve wrote:
I have some small rust spots which I have sprayed with Corrosion Block or others will Ospho ect work over that?
Steve W

Click to expand...

*Steve,

Corrosion Block is an oil based product that may prevent rust spreading or starting. You would need to wash it off with thinners or similar before applying Ospho.