Muriatic Acid????

Mike Johnson · Post by **Mike Johnson** » Nov 1st, '05, 09:18

After pulling Liberty out of the water yesterday, the severn river rash ( a brown stain) is quite evident around the water line, even after spray cleaning. It was suggested that I use muriatic (sp?) acid in a diluted 50% solution to remove the unsightly mess. Need your ideas!!!! Where can I find this stuff and is there something else better? Thanks again

Frank Vernet · Post by **Frank Vernet** » Nov 1st, '05, 09:27

I might be wrong, but the last time I heard muriatic acid, otherwise known as hydrochloric acid, mentioned was by a mechanic who was dipping raw water cooling components to remove a buildup of seawater mineral deposits. Not sure I'd spray it on your hull. There must be a better way of cleaning Chesapeake Bay grime off your waterline.

Ben Thomas · Post by **Ben Thomas** » Nov 1st, '05, 09:46

masonry and concrete contractors use this to clean and acid wash brick, stone and concrete. Potent stuff, I've used it, not on fiberglass, my dad was a bricklayer, middle school and high school, most summers were spent helping out on the job. That meant clean up. A 50% dilution is going to burn your skin. At 20% you still must use thick rubber gloves. The fumes are not good for you.

50% you really should use a good respirator. I would not use this product until you tested and viewed results on something that would be throw- away.
Although I have seen yards roll on paint stripper then power wash to get at several layers of bottom paint.
That said: Proceed with caution.
Best of luck, let us know the resolution Ben

Mitch F · Post by **Mitch F** » Nov 1st, '05, 09:50

Mike -
I know it sounds weird but plain old lemon juice sometimes works well to clean off the brown stain, particularly if you do it shortly after haul out. A quart of it is pretty cheap at the local grocery store and it sure won't burn your hands. Just sponge it on and let it set for five minutes or so and then rinse with fresh water and hopefully your stains will be gone.

Good luck.

Mike Johnson · Post by **Mike Johnson** » Nov 1st, '05, 10:07

Thanks. I thought this was a bit extreme. Been doing some research on it this am and there are several marine shops that recommend it for this purpose and even sell it. I do know that i have to use gloves and eye protection. I may try the lemon juice first. I'm thinking if I use anything too caustic, My bootstripe will be history and I will have to repaint it. I just did that this past spring.

Ray Garcia · Post by **Ray Garcia** » Nov 1st, '05, 10:46

Oxalic acid has worked very good for me. $7.99 for a plastic 16oz. container from West Marine. SHould last you a few seasons. (link below) It comes in crystalline form. Mix a little less than stated; in a spray bottle. I would recommend using gloves, mask, eye protection if you have sensitive skin or not comfortable using acid. Keep pets, & children away. Have plenty of water around, just in case. Use common sense when applying, wait then rinse. Should remove most stains (rust, tannins, etc.) You may have to re-apply for stubborn stains. Also works on teak. Go easy though and rinse thoroughly.

Oxalic acid also comes in gel and paste forms. Oxalic is the main ingredient in other fiberglass "stain removal" products.

http://www.westmarine.com/webapp/wcs/st ... 0001/19989

Cathy Monaghan · Post by **Cathy Monaghan** » Nov 1st, '05, 11:11

Try On/Off. It's a Marykate product designed to remove stubborn stains from fiberglass boat hulls. You should be able to get it at any chandlery including from the big guys (BoatUS, West Marine, Defender, etc.). It's also powerful stuff, so be sure to protect your skin and eyes while using it.

On & Off Hull Cleaner (Marykate/CRC Industries)

<a href="http://www.crcindustries.com/CRCWEB/Def ... =357"><img src="http://www.crcindustries.com/catalog/im ... 2.jpg"></a>

Mike Johnson · Post by **Mike Johnson** » Nov 1st, '05, 11:24

thanks I will give it a try.

mahalocd36 · Post by **mahalocd36** » Nov 1st, '05, 11:47

Cathy's right. This stuff is Nasty but works unbelievably well. Have water ready to rinse off. Wear gloves and mask, long sleeves, etc. At the boat show's D-I-Y seminar the woman suggested applying it with a paint roller on a stick so you could stay away from it. This stuff took off stains nothing else would touch, and didn't seem to harm the gelcoat nor bootstripe paint - though I rinsed it off pretty quickly with water, doing small areas at a time.

Jim Sullivan · Post by **Jim Sullivan** » Nov 1st, '05, 11:59

I believe "On/Off" cleaner is a mixture of hydrochloric/oxalic acids which will certainly work although as others have noted so will oxalic acid alone.

I use Behr Deck Brightener (Home Depot) which is a concentrated solution of oxalic acid. I buy a gallon for <$10 and dilute it when needed with about 4 parts water. A gallon lasts several years for this application. I use a plastic spray bottle to apply the diluted product. I keep a spray bottle on board during the season to periodically clean the waterline. This has worked very well for me and turns out to be rather inexpensive. A light spraying and the stains disappear.

Good luck,

Jim

tartansailor · Post by **tartansailor** » Nov 2nd, '05, 06:26

Muriatic Acid is hydrochloric acid available in masonry supply stores. If you dilute NEVER!!! pour water in acid; ALWAYS pour acid to water.

Why go through all that fuss when "Bartenders Friend" scouring powder which also contains oxalic acid works just as effectively, and a lot more user friendly?

Now I clean off the scum line with 800 grit WET sandpaper in my palm size finishing sander and that job goes really fast.

Dick

Jim Lewis · Post by **Jim Lewis** » Nov 2nd, '05, 07:45

Boat yard I have used on and off for 25 years uses the stuff to clean hulls and such, but they never apply it to dry hull.....always wet the hull well before applying, guess that is how they reduce the power of full strength. I did it once myself and after buffing out the hull everyone thought I had new paint job for about a year....
I think that all hull cleaning products that produce results have some form of acid in them....in fact around here the brown stain on the hulls is from acid in the water.... so seems like the gelcoat is able to asorb fluids, so timing of treatment may be everything, even the marine products sold in stores.....good luck with whatever you try......

Mike Thorpe · Post by **Mike Thorpe** » Nov 2nd, '05, 08:15

The easy and cheap solution to the brown warer line stain is industrail strength toilet bowl cleaner. Mix it 50/50 with water, apply with a soft brush & scrub lightly. Do the entire water line and then rinse off with fresh water. I've used it on my CD-27, CD-36 and my Saga 43. It's cheap, fast and won't bother the boot stripe but it will remove any wax.

You can buy it in any hardware store that has a janitorial section, about $3.00 a bottle which is enough to do my 39' water lline twice.

Mike Thorpe
Saga 43 Adagio

Mike Johnson · Post by **Mike Johnson** » Nov 2nd, '05, 10:48

thanks for all the suggestions. I will let you know what works best. I plan on having and experiment on the best method suggested. Gonna cost me more but then we all will know. I will respond back and let you know what I found worked best. I will be attacking the stain on Sunday. BG

Mike Johnson · Post by **Mike Johnson** » Nov 2nd, '05, 10:49

thanks for all the suggestions. I will let you know what works best. I plan on having and experiment on the best method suggested. Gonna cost me more but then we all will know. I will respond back and let you know what I found worked best. I will be attacking the stain on Sunday. BG

The Cape Dory Board

Muriatic Acid????

Muriatic Acid????

Usually Used to Dip & Clean Engine Components

muratic acid

Muriatic acid

Oxalic Acid

Try "On & Off Hull Cleaner"

On & Off

Re: Try "On & Off Hull Cleaner"

Muriatic Acid

Acid

Cheap and easy solution

thanks

thanks