@RumDiet never heard of that effect....all professional boat cleaners use muriatic acid to clean hulls - they've been using it on my hull for 4 years now and I see no ill effect....but I've not been looking for it either.
@Glassman is there something I should be doing to offset this effect?
OK, happy to give you my personal opinion and preferences, but that doesn't mean any other methodology is bad or wrong. Capish?
Acid has been used for, well, before my time.
Boat yards use all kinds of acids for all kinds of things.
Muriatic acid is great for removing the nasty yellow-brown stains you'll get from leaving the boat in a slip for a time.
And in bulk it's cheap.
Many of the off- the- shelf hull cleaners come pre-measured, but some don't and have to be reduced. So watch that.
Most contain, among other things, hydrochloric acid, phosphoric acid, or oxalic acid. Maybe some other stuff, who knows these days.
Typically oxalic acid is in something most of us use- same stuff in Bartender's Friend and some other stuff you might have around the house like toilet bowl cleaners, etc.
Either way, yes it's used, no it won't harm gel coat if used properly.
That said, I don't use it if I don't need to. I don't leave the boat in the water much. Maybe a week at a time at most and that's in fresh water. Otherwise, I pull the boat daily and wipe it and clean it and have been found waxing it at midnight in the parking lot if it needs it. Or I need it. The cleaner you keep the boat, the easier it is to keep it clean. That's just me.
If you let those little organisms live on your hull while the boat's in storage and expect to clean it off easily in the spring, well, good luck with that.
My personal approach to keeping gel coat looking new is to wash it often with a very mild soap and not much of it - y'all know not to ever use dish soap - RIGHT?
If, after washing you have yellow stains, a scum line, etc. use a little elbow grease. If that doesn't get it then a mild acidic solution should do the trick.
And use your head. Don't leave it on too long, scrub and rinse it off with plenty of clean water, just like the label probably says. Yeah, I know..."What Label?"
Read the label, please. You'll get pissed when some of this stuff lands on aluminum! Or paint, or any other thing you don't want messed up. (one of the reasons I rarely use it)
If you are spraying the stuff, be careful. Wear a mask and glasses, brushes splatter and acid wrecks clothes - so don't bitch if your favorite board shorts come out of the wash with holes.
Acid won't wear off gel coat, it's not abrasive. It's actually much better to use a mild acid solution that anything abrasive from the standpoint of maintaining the gel coat. Also, sometimes acid is the best way to get stains out of porous gel coat.
The guys who see stains come back faster are the ones that didn't finish the job.
After cleaning with any acid hull cleaning product you have to rinse it well, you can dump some baking soda in a bucket of water and do a quick wipe down to make sure it's neutralized if you like.
Then I would polish the snot out of the area treated to help reduce/minimize the porosity and put a shine on the gel coat. You want it to feel like glass.
Then a good coat of wax.
Just be careful with whatever you use. I've seen collateral damage done to all kinds of stuff - canvas, vinyl, aluminum, paint, decals, rubber, somebody's favorite whatchamacallit - you get the idea.
Elbow grease is one of the best things I've found to get a boat looking good. Unfortunately it doesn't come in a spray bottle.
Don't use the nasty stuff while the boat is in the water or where it drains into the stuff in which your kids and hopefully fish swim, OK? Thanks.
