by Breakin Wind » Thu Oct 04, 2012 2:43 pm
Hi Kent,
This is from a posting I did last fall regarding waterline scum and stains...
I don't know how I came across it, but I have found the most amazing product for cleaning lake scum and discoloration off of fiberglass.
MaryKate On & Off Hull & Bottom cleaner. Again, I'm not sure where I heard about it but this stuff is amazing! I searched this forum and can't find any references to it, but I do see references to MaryKate waxes etc.
My DSII hasn't been in the water yet, but I have a fiberglass Glastron ski boat that spent 45 days tied to the dock before I got a lift installed and it was just terrible how discolored and stained the boat was just in that short time from the waterline down. (Very weedy area of the lake) I tried powerwashing, scrubbing and all kinds of cleaners, but this On & Off is great.
It's kind of a thin milky liquid that I poured into a plastic roller pan, and used a paint roller to, well, roll it onto the boat bottom and then spray it off with a hose. It comes completely clean and looks brand new. No scrubbing per se, but as I said I used a roller so the normal back & forth action does a little natural scrubbing, but this is truely amazing stuff. I think I paid... $12 for 1/2 gallon on ebay?
So that's the good news!
The bad news is this stuff is major league toxic. We're talking serious rubber gloves and eye protection, and just don't plan on breathing when you're near it. I was working in the drive with a decent crosswind so as long as I was upwind all was well, but you don't want to even whiff a little bit of this stuff. The whiff I got (which is how I learned not to breath near it) smelled a very very sharp tangy smell but it burns your nose, throat and lungs almost immediately. Don't smell it to find out. There's 3-4 different acids in it that do the job but it cannot be used on metal so you also need to put a plastic sheet or blue tarp on your trailer and be sure to hose it down afterwards.
The EPA would likely prefer that you capture the run-off and dispose of it in a hazardous waste facility. Definitely keep it out of the lake.
I didn't mean to do a commercial here, but water line scum has been the bane in my boating for a long time and this is the answer I've been looking for. Wanted to share the info for others who also hate water line scum.
jdoorly responded with:
Corrosive to skin & eyes, may cause resperatory tract burns, vapor harmfull.
That sounds like my old friend oxalic acid. I use it to dewax before adding a graphite finish or painting. Great stuff. Of course you don't have to scrub, you can't, it makes bristles evaporate! Don't fail to rinse it off quick or you'll be watching your gel coat blow off in the wind for years.
You're also supposed to cover your trailer with a tarp to protect that finish, but my tarp cover failed last year due to a wind and my trailer suffered no ill affects.
Good Luck- Scott