Cleaning the Dirtiest Waterline

[ABC34]

I have the dirtiest caked on waterline.
I tried all the commercial cleaners sold but have no luck.
Does anybody know of some chemical that will lift the sh----t ?
short of acid?
Thanks

[Nemo55]

Have you tried a steam cleaner??

[minaret]

If it's gelcoat wetsand and buff it. This is very common. No cleaner will get heavy waterline staining perfect, but sanding will make it look brand new again. I even take a little 2000 grit to paint stains sometimes, but paint usually doesn't stain like that.

[1paulg]

Just above the waterline on the gel coat -oxalic acid is good ..clears stains quickly ..but wash then repolish...
havent got any simple answers for the actual waterline tho..

[exsaylor]

Have you tried toilet bowl cleaner?
I have used it successfully on dirty stained decks.

[Gelfling]

You mentioned you have used all the 'commercial cleaners'. I always use Dawn dish soap. Hasn't let me down yet!

[sy_gilana]

Try "Shower Tub 'n Tile" by Zep. It gets rid of the ICW moustache.

[Beersmith]

have you tried On/Off? Best acid for this type of work.

that stuff is intense, but got rid of a lot of waterline nastiness on my boat

[Kettlewell]

The answer is Prism Polish. Best fiberglass cleaner going, plus it's great on metal. It will take off the ICW mustache.

[svpattyd]

Try BioGreen Clean. Plant enzyme product and works great! Cleans everything on the boat and totally natural.

[belizesailor]

"ON/OFF" is a potent cleaner and will almost certainly clean your water line, but be careful with this stuff because you can also damage your gel coat. If you use it, be sure and wax the cleaned area immediately because if you don't the gel coat will re-absorb the water line funk even worse than before and it will be much harder to clean.

See On-Off Hull and Bottom Cleaner.