Acid washing your hull

[bhoff]

Ok, I've left my 19' boat in the lake since April.  I've lost about 4 mph because the bottom of the boat feels like sandpaper from the growth (fresh water).  Used Starbrite Hull cleaner last night and it removed the discoloration, but the gritty feel remains.  A friend of mine said to use muratic acid from the hardware store (used to clean concrete) and let it sit on the hull for a couple of minutes and then wash it off with a pressure washer.

Has anyone done this?  Will it hurt the trailer and if I wash off the trailer right after I apply the acid.  Will the pressure washer damage the gel coat?  

I've never used a pressure washer on the hull, any advice you can give is appreciated as it will cost $250 to have the boat put in a sling and cleaned by the marina.

[Dream 'Inn]

I keep my boat on a lift.  A few times a year I use a 50/50 mix of muratic acid with water (make sure you pour the correct one into the other, not the other way around).  Basically, make sure the bottom is dry, and put the mix into a spray bottle and just go around and spray it on, then maybe use a light brush just to spread it if necessary.   You may need to spray again in some spots.  Then just hose it off.

There is another product called FSR that probably works just as well.  There is someone on my pier that uses it almost after every time he takes it out for a night.  Seems to do very well too.

As far as getting the acid on the trailer, you do want to get it off the trailer or try not to get it on it too much.  I used to have a 24' that was on a trailer.  Back then I used On/Off by MaryKate around the scum line.  That also worked extremely well, but it's active ingredient is acid too.

As far as using a pressure washer, I used to use a 2400 psi on my 24' without any issues.  

I couldn't say though if any of it would take the gritty stuff off, never really had that much of an issue with growth, just discoloring.

[denniscarguy]

Go to the dollar store and buy a tub n tile cleaner named "The Works" put it in a spray bottle and it works fine and is only $1 per bottle.

[bhoff]

Well,  the muratic acid worked really well.  Hull is back to white and smooth.  Used it full strength, diluted 50/50, and 1/3 acid 2/3 water.  All 3 mixtures seemed to work very well, although I can tell you when it hits the driveway it smokes and sizzles like something out of the movie "Aliens".  The smoke from the acid on the driveway will also burn your nose so hold your breath when you have to reach under the boat.  Also use a sprayer instead of a sponge because it will keep the acid from getting on your forearms.

Pressure washer did not groove the gel coat at all (although it was a weak electric pressure washer).

I feel much better now that my boat is clean.  I'm very particular about how she looks........

[Sherminator]

you can also use that acid for hard waterspoting on the hull too, just be sure to rinse it well and DO NOT leave it on for very long!!!!

[mikesharlow]

I too keep my boat in fresh water all season and one it comes out its stained and nasty. In fact I had a hard time cleaning the hull last year. Not sure I feel comfortable using/mixing muraric acid, I think I would feel more comfortable using a product like Mary Kate on/off. I have never used it...can any tell me how well it really works with a pressure washer?

[Dream 'Inn]

you can use Mary Kate just by spraying (take a sprayer from an old bottle since it doesn't come with one) it on and then hosing it off after letting it sit for a couple minutes.  I do believe the active ingredient in it though is muratic acid.  I just did the acid/water mix this past Friday, works very well. Just make sure to pour the acid into the water.  FSR is another good product to use, without that acid scent.

[mattie]

Glad to hear it worked bhoff.

Last week, I did the same. First, "Hull Cleaner" from Starbrite - it worked well to remove the algae.

Then I was left with the calcium tea stain on the new bottom. I used a commercial calcium, lime, rust removal liquid called ZEP. Similar to CLR.

$9.99 for a gallon. Brush it on, wait, brush it a bit more & hose it off. Good as new.

As far as the trailer goes - I just kept hosing it down as I worked. None the worse off.

[attachment=1:2w8unurh]zep.jpg[/attachment:2w8unurh][attachment=0:2w8unurh]clr.jpg[/attachment:2w8unurh]

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