Getting the green algae stain off my boat?

[Sore Thumbs]

I have read about different methods to do this. I use acid but I’m afraid it is going to eventually hurt my gel coat. Will waxing with compound work? Just curious what you guys suggest. Thanks 

[196champ]

Just tried the magic erasers on my white hull, works great.  Going to keep a few in the boat and use as needed.

[Sore Thumbs]

My boat is white and has a slight green stain all around it. Probably looks good from a distance but up close you can see it. Just wondering if it’s deeper than just the surface 

[NebSchmidty]

I've used automotive 3m rubbing/buffing compound with good success on mine.  It's the stuff they use when wetsanding and buffing clear coat.  

I think if your gel coat is in good condition, and the stains are just from regular outings (rather than being docked in water for months) then you'll be fine.  We've got pretty stained water at home from lots of vegetation, so my white hull usually gets a discolored ring after several outings on the lake... but it usually comes off pretty easily.

A cheap electrical orbital buffer makes it a lot easier than doing it by hand.

[Flysmallie]

32 minutes ago, 196champ said:

Just tried the magic erasers on my white hull, works great.  Going to keep a few in the boat and use as needed.

I'd be careful with those. It is scratching the finish. Probably not noticeable on white but somebody does that on a black boat and you will be able to tell every spot it touched. 

[Flysmallie]

11 minutes ago, NebSchmidty said:

I've used automotive 3m rubbing/buffing compound with good success on mine.  It's the stuff they use when wetsanding and buffing clear coat.  

I think if your gel coat is in good condition, and the stains are just from regular outings (rather than being docked in water for months) then you'll be fine.  We've got pretty stained water at home from lots of vegetation, so my white hull usually gets a discolored ring after several outings on the lake... but it usually comes off pretty easily.

A cheap electrical orbital buffer makes it a lot easier than doing it by hand.

This is your best option. It will get everything off there and polish the finish. Then apply some nice paste wax and it will make it easy to keep clean. It's a nice workout for your arms though. 

Any kind of acid is just hurting the finish. Just like the eraser pads. And the problem with that is if that finish isn't nice and shiny then it's not only ugly but it's easier for these stains to take hold. And harder to clean. So then you just get into this continual cycle. The finish getting a little bit worse each time making it easier to look bad. Get it nice and smooth and shiny. Apply some wax. And it will be simple to keep clean. 

[Quillback]

I would also recommend a wipe down of the waterline every time you pull your boat out.  A little time consuming, but you won't get any of that build up. 

[fozzype]

You need to get the boat as clean as possible before you buff it.  I have done this for years and what you want is to take off the green with a harsh cleaner first.  I recommended foaming lime away.  Just remember to not let it dry!  This will not effect the clear coat in any way. If you begin waxing before cleaning, you sometimes can "burn" the slime into the gel coat and it will require even more work to remove.

Then after getting it clean, buff with a mild rubbing compound , then a  cleaner wax.  I recommend a fine cut 3M product or a meguires synthetic wax. The gel coat is very thick and you are trying to remove a tiny fraction of the outer surface of it and then buff back to a shine.  Then seal it off with a good wax like RejecX.

[196champ]

Guess ill throw those erasers out....

[David Unnerstall]

1 hour ago, NebSchmidty said:

I've used automotive 3m rubbing/buffing compound with good success on mine.  It's the stuff they use when wetsanding and buffing clear coat.  

I think if your gel coat is in good condition, and the stains are just from regular outings (rather than being docked in water for months) then you'll be fine.  We've got pretty stained water at home from lots of vegetation, so my white hull usually gets a discolored ring after several outings on the lake... but it usually comes off pretty easily.

A cheap electrical orbital buffer makes it a lot easier than doing it by hand.

Harbor Freight sells an orbital buffer that is both cheap and good.