Fall haul-out cleaning

[kokko]

I think the most important thing to do when you haul your boat is to pressure-wash it immediately. Wait, as I did, and the grime does not want to come off.

Truelove sat on the hard for a few weeks until I got her home and started to clean the hull yesterday. I started with a pressure-wash, which did not tough that layer of grime right at the water line. I attacked it with a power buffer and polishing compound, that remeoved most of it, but leave grime swirls. THese I removed with a damp terry cloth towel and a lot of hand rubbing.

Is there a better way to remove the grime?

I think the grime is a composite of algae, oil and various freshwater marine growth.

[Breakin Wind]

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

[GreenLake]

The main active ingredient is hydrochloric acid (20-25%), and yes some other acids as well. I would go slow with harsh stuff like that.

There are other formulations with lower acid concentrations that may work just as well.

Whatever alternative you use, always look up the MSDS (Materials Safety Data Sheet) that manufacturers are required to provide. There you can find a thorough listing of all the ingredients and their dangers to health and safety (fire/explosion hazard).

That's where you find all the information that should have been disclosed to you on the package, but which suppliers don't want you to know about.

Practical Sailor ran a test comparing MaryKate to a less toxic substitute (Rydlyme). The upshot is that you can tell it's not as aggressive but its also not as dangerous. Possibly worth a try.

Disclaimer: I don't leave my boat in the water, so all I do is wax it well and rinse it off every time I take it out of the water. So I don't have first hand experience with "slime".

[talbot]

I'm still confused about the best approach. I've been using Interlux VC17 antifouling paint every 2 years. Works great, and only 20% copper. But I feel bad about the 20% copper. Some neighbors at the dock just go with waxed gel coat or enamel, and then use scrubbing and chemicals. I've done that in the past, and I felt bad about those chemicals. A new wrinkle is the anti-invasive species effort in our state, which asks us all to bleach and dry our boats when moving between any two bodies of water. Is there any consensus on the proper balance between invasive slime and poisonous chemicals?

[GreenLake]

Yes, give up boating and watch the AC from your couch....

Actually, the balance between reasonable results and acceptable footprint is a nice optimization problem and I don't think I know of any definite answers - as new products come out, old experience needs to be updated.

I usually move my boat between launches on what is effectively the same body of water, or between salt and fresh water. That's not the scenario that helps the typical invasive species get anywhere new. (I hope).

Fouling and slime are very dependent on locality, so you also have to figure out what works best for your area, so you don't shoot sparrow with canons (or vice versa).

Generically, I could suggest reading Practical Sailor - they run regular tests of antifouling (and many other boat-related chemicals) and do keep up with the changes in formulation that manufacturers apply in response to regulation or ecological concerns.

[kokko]

It may not be a fiar comparison, but I hauled my other boat - a Catalina 22 from the water on Saturday and pressure-washed it the same day. It was a lot easier to clean than my DS1, which sat for three weeks before cleaning.

What worked well on the C22 was pressure-wash followed by polishing compound, then wipe off the polishing compound with a damp towel. I had a lot of trouble just buffing off the polishing compound, hence the wipe down.

[talbot]

I agree. Time is of the essence. Our local slime dries into a crust that is more easily chiseled than rinsed off.