Since it's still cold here, and I can't do any work outside, I decided to polish the lowers on my new ( to me ) Imco lowers. I used 6 sheets of 220 wet sandpaper, 2 sheets of 320, 2 sheets of 400. Sanding took about 5 hours to get all imperfections out of one drive . For polishing I used white polishing compound that can be found at any auto parts store and a polishing wheel mounted on an electrick drill. For a brighter finish I may try some Semichrome polish on it. It came out pretty well. Unfortunately it looks like some casting imperfections were repaired at the foundry with welding rod. They show up as those round spots. In sunlight they aren't as noticable.Hers a pic after one was finished.

Looks good. How many drills did you go thru?

I have an electric 3/4hp motor that a made an extension to slip over the shaft to extend it out and mounted a 10 or 12" wheel to. Just like a regular buffing motor. Makes it so much easier. Are you going to clear coat them? Could even silver paint them to cover the spots.

they look good
In conversation with a few people I have heard that a slightly rough lower is slightly faster Have you done any research on this I no this topic has had some differing opinions

I haven't heard that unpolished is faster on the lowers. Maybe on the props. I doubt if it'll be noticable anyway. The drill's holding up ok but my arms and hands are sore. I'm not going to clear them, just use mag wheel cleaner on them every time I wash the boat.

That looks great.Did you wet sand the whole time and did you use a sanding block.I am going to takle that on my Promax 300 lowers.

Ian, that looks great. Nice work. You might try some sealing polish for alum to help hold the shine between touch ups. I think Mothers or Wizard makes some very good ones.

the one you finished looks awesome compared to the before pic

Wonderful! I'll bring mine right over!

My Imco lower has the same casting marks. I dont know why they are there, but it appears they are plugs that get welded in after the casting process. I polish mine once in a while but it doesnt hold up. I run only in salt water, dont know if thats why, but after a short while, it looks like I didnt do anything to it.

8 hours of polishing, yet I can't get him to unload the dishwasher

I just checked for myself in the basement, they look even better in person, thanks for working hard to save us money