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On-Off Hull and Bottom Cleaner
$16.36In Stock
On Off Hull Cleaner
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4.5
Based on 21 Reviews
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On-Off Hull and Bottom Cleaner Customer Questions and Answers

10 of 42 Questions

Question

I am looking at purchase of a 2000 Crownline that at some point sat in freshwater for an extended period of time. There was alge that was not removed from the bottom when the boat was pulled from the water. It is now hard and crusty stuck to the bottom that a fingernail will not take off. Anyone used On-Off for this type of bottom cleaning? How did it work?

Asked on 10/01/2011 by bruceschneider21 b

Top Answer

100% - Comes in a one gallon milk jug type container.

Answered on 10/06/2011 by GREGORY ANDERSON
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Gregory, I have one more question: What strength hydrochloric acid did you purchase? Thanks Bruce

Answered on 10/05/2011 by bruceschneider21 b

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Just be sure to throughly wet down the boat trailer since the ON/Off is not to be used on metal. They recommend covering the trailer with a tarp but wetting down the trailer before applying the ON/OFF has worked for me for more than 5 years. You may not want to clean on a driveway, the chemical acts similarly to muriatic acid. The power washer is only for convenience, you can use a garden hose because the algae and slim literally comes off during application of ON/OFF. I use a very soft 10 inch brush dipping into a paint pan. Sincerely I can wash my Sea Ray sport 185 in 15 minutes. Any more questions do not hesitate.

Answered on 10/03/2011 by GERALD BOMAY

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What did you end up using or doing to correct the dried algae problem? Bruce

Answered on 10/04/2011 by bruceschneider21 b

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Steve. Appreciate the sales pitch and endorsement of the product. Bruce

Answered on 10/03/2011 by bruceschneider21 b

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Thanks. The owner and I went over the boat today. I could not hardly touch the stuff with rubbing compound and elbow grease. Tried scraping it off with a window film applicator/squeegie but had very little success. As a result he has dropped the price of the boat another $2000.00! I am takin it out tomorrow for a test run and see if it will pull me up on my wakeboard. Present boat (VIP Vegas 185) just does not have the power to do it. Thanks again. Bruce

Answered on 10/05/2011 by bruceschneider21 b

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Thanks again. Bruce

Answered on 10/04/2011 by bruceschneider21 b

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My hull was not quite as bad as yours, but mine has a year's worth of algae when I clean it. On-Off is like boiling hot water on butter! I am sure that if you applied it and let it soak a little while, your crust will come off. If it doesn't there is probably little that can be done with your hull, because I can't imagine using anything stronger!

Answered on 10/03/2011 by BRIAN KRAMER

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My situation is a little different. I have a Scarrab Panther / White hull no bottom paint. We try to not leave it in the water very long (hull stays waxed for speed). Anyway after 2 weeks in the hull is stained yellow with a little growth. I power wash as necessary to clean the excess growth. That leaves it clean but still stained. I use the Hull cleaner describe "BUT" there is a better version!! Bottle & label are the same but it's blue & yellow. That product works much better and smells much better when applied! It's a blue gel that I brush on. Same manufacture. I've used both & the "Yellow" bottle same manufacture in my opinion is "The way to go". That chuncky stuff may need some good olf fassion elbow grease Or soak it the the Hull cleaner gell & see what happens!

Answered on 10/03/2011 by jim huettenmoser

Answer

I used a 25% mix of hydrochloric acid and water in a all plastic pump up lawn weed sprayer. I let it soak on the boat for about 30 minutes. The acid solution will actually foam as it contacts the encrustation. I had to apply a second application to some areas of the boat to remove all the encrusted material. The acid was about $5.00/gal. at the nearby farm store. NO damage to the boat/outdrive/trailer. I did however rinse with a lot of water. Used a pressure washer to rinse solution off after application. Wore a tyvek suit and face shield, respirator and stayed up wind of any mist. Be aware this is toxic stuff. It was the only way I found to remove the white/gray hard encrustation. Have used this method three times on the same boat. Boat sets in the water five months a year in fresh water in Wisconsin. The other responses to your original post have missed the point. What you have described is a HARD crust of material on the bottom of your boat. By-in-large what the other respondents have described is cleaning a scum line or the like. I am sure the product works very well for light cleaning but can not come close to removing what you are up against. Good luck and be careful if you go this route. This method works very well but could be dangerous if you do not use proper safety equipment. The local boat dealer would do a similar method to clean my boat for a price of $475.00. Homelite

Answered on 10/05/2011 by GREGORY ANDERSON
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Question

How much do you need to clean the hull of a 19 foot bass boat?

Asked on 02/08/2013 by Undisclosed

Top Answer

I clean my 20.5ft Champion 4 times with 1 qt bottle. Thats from the rub rail down. I don't want it to get on my carpet. And remember to cover your painted trailer surfaces w/plastic Its great stuff, but be sure to heed the warnings on the bottle. Steve McKinzie Quality time Guide service 318 687 0195

Answered on 02/15/2013 by STEVE MCKINZIE
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one bottle and a pair of rubber gloves.

Answered on 02/14/2013 by GUY JOHNSON

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Sorry I don't have an answer yet. First time purchase and I won't try the product until next summer.

Answered on 02/14/2013 by DALE WOODWARD

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No more than quart. If you have bottom paint just enough for water line less than a pint. Wear gloves mask and very very old clothes.

Answered on 02/14/2013 by ROBERT KOWALSKI

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One quart should be sufficient. Wear Protective gloves and safety glasses! Product works great. Have Fun

Answered on 02/14/2013 by GEORGE SHEPPARD

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Depends on the staining. For a general seasonal cleaning I will mix half a quart with a couple gallons of water. On the other hand I have used a quart on just the waterline of a 20 foot boat. The stuff is strong. It also doesn't go bad, so there is always a bottle at hand in my shop to clean a stubborn stain.

Answered on 02/22/2013 by BART WESP

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Probally a quart. Just keep brushing it on and then just hose it off. On and off is the best. Buy a good respirator mask and chemical resistant gloves. Do not get this chemical on your skin.

Answered on 02/14/2013 by CRAIG MILLER

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Based on my experience it depends on how badly stained and what type of stains you are dealing with. This product is caustic and a little goes a long way if you are dealing with your typical water line staining. However if you are attempting to remove staind from leaves sitting on the gelcoat it does take more. Assuming you are cleaning the entire hull and using additional for spot stains I believe 1 gallon would be sufficient.

Answered on 02/14/2013 by BRIAN WILLIAMSON
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Question

can this prodduct be used on the upper decks on a F/G house boat??

Asked on 08/27/2011 by James McCord

Top Answer

Sorry, but I have not used the product. It sits on the shelf unopened.

Answered on 09/02/2011 by PETER LUDWIG
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Answer

James, while I am not familiar with the F/G house boat you you reference I will tell you that the On & Off hull cleaner is the strongest gel coat cleaner that I have used. I will caution you that it is a very caustic chemical and the directions warn against it coming into cotact with a number of materials, however it very effectively cleans stained gel coat. I used it to remove leaf ad rust stains from my boat with great success. The only concern I would have about using on an uper deck would be what any run off may fall onto.

Answered on 09/01/2011 by BRIAN WILLIAMSON

Answer

Hi: Check the ingredients in this product. This is serious stuff. It's designed to take the season's nasty buildup off the bottom of a boat. If memory serves me, it has two different acids, and I can tell you that I began to choke up when I was down wind from the boat. After rinsing, I crawled under the boat and used a Brillo/ SOS pad, and clorox to scrub off the rest of the scum. My boat isn't a show boat, it soaks in the Lake all summer. How dirty are your decks? ON/OFF was helpful in getting my job done. It's strong stuff. Jim

Answered on 09/01/2011 by JIM MACLAREN

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james,on-off is very good below the rub rail for stubborn stains, but it is so strong i'm not sure how the run off could be controled above it. The cautions on the bottle say to keep it off painted surfaces like your trailer. Use with caution

Answered on 09/03/2011 by STEVE MCKINZIE

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I haven't had a chance to use it yet. Ed

Answered on 09/02/2011 by Edward Hutchinson

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yes, it can be used on any fiberglass surface, but try to avoid getting it on anything metal because it will corrode or discolor it

Answered on 09/01/2011 by JOHN STAGER

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On-Off has 3 acids - phosphoric, oxalic and muriatic (hydrochloric) - as a consequence there are few things that wind up on the bottom of your boat it will not remove, and with very little elbow grease. As reported earlier and elsewhere, it can damage paint and will powder galvanizing on your trailer, even if you keep the metal flooded with water; it is necessary to cover exposed painted or galvanized trailer parts with plastic.

Answered on 09/14/2011 by JOHN FLOOK
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Question

Can you use On-Off on glass?

Asked on 09/12/2013 by Susan Verbage

Top Answer

Ive used On&Off on fiberglass only.Does great there.

Answered on 09/13/2013 by STEVE MCKINZIE
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Susan, I'm not sure. I've only used it on the fiberglass bottom of my boat.

Answered on 09/16/2013 by JOHN HEATON

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Thanks, I have some stains on my car windows that are from some kind of cleaner that I used (do not have it anymore) that was supposed to clean everything. Not! It left streaks that no one has been able to get out. Only luck I have had was a detail guy that used a compound and an electric buffer and he was afraid to use the buffer for too long because it got the windows so hot. My brother sails and he told me about this On and Off to use on rust stains on our brick and window from a leaky AC. Worked great for that. Just wondering. Thanks for your input

Answered on 09/13/2013 by Susan Verbage

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Thanks so much for taking the time to reply. I actually called the manufacturer and a technical person told me that I should not use it on my auto windows. So, that solves that!

Answered on 09/16/2013 by Susan Verbage

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Thanks. I appreciate you taking the time to answer this question.

Answered on 09/12/2013 by Susan Verbage

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Have never tried it on glass.

Answered on 09/12/2013 by DALE WOODWARD
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Question

Can I clean water spots on windshield?

Asked on 12/27/2011 by Undisclosed

Top Answer

Truthfully, I have not tried to do so.

Answered on 12/28/2011 by EUGENE J SABAITIS
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Answer

This cleaner works very well on gelcoat-- a great product. I have not used it on anything else.

Answered on 12/28/2011 by CHARLES MARTIN

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I have used ON&OFF for two years and have never seen anything clean a hull better, but I would hesitate to use it on a windshield

Answered on 12/29/2011 by STEVE MCKINZIE

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Don't know about the windshield, but it did a great job on my hull. I'd try it first on a small out-of-the-way spot and see what happens.

Answered on 12/28/2011 by WILLIAM PETERS

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This stuff is especially for hull cleaning. I have never used for glass. Quit expensive to clean glass. Have you tried ammonia diluted in water with a little dish soap?

Answered on 12/28/2011 by GERALD BOMAY

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Don't know. It's strong stuff and works great on the bottom. As with anything like that you need to try it in a small spot and see how it works.

Answered on 12/28/2011 by ROBERT HANDLER
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Question

is it concentrated?

Asked on 04/04/2018 by Michael from Ben Wheeler, TX

Top Answer

This product is used at full strength, it is not a concentrate.

Answered on 06/01/2018 by JD Tech Associate
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Answer

It is supposed to be used straight so it's not "concentrated". It can be reduced with water but probably won't be as effective.- if your hull is not bad, reduce. If it's real bad, use it straight.

Answered on 04/05/2018 by hidenobu

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No, it's supposed to be used full strength

Answered on 04/04/2018 by jkmoritz

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yes

Answered on 04/05/2018 by bob

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Yes it's concentrated but that's the way to use it.

Answered on 04/05/2018 by b.work
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Question

how does this product work? does it involve a lot of scrubbing?

Asked on 08/08/2012 by Undisclosed

Top Answer

Hull and bottom cleaner is amazing. Follow the directions and it works great with no scrubbing.

Answered on 08/09/2012 by PATRICK TRETTS
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Answer

Excellent product. I spray it on and rinse it off. doesa great job.

Answered on 08/08/2012 by MICHAEL MILES

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>>does it involve a lot of scrubbing? Not at all. Apply it with a big sponge, and simply wipe off the growth and stains on the hull. This is basically an acid mixture that attacks any organic growth. I also use it to remove barnacles from the trim tabs. Make sure to wear rubber gloves and goggles. This is great stuff.

Answered on 08/08/2012 by DARIO FERREIRA

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No scrubing required. Excellent for brown waterline stains. Wipe on wit damp sponge, use rubber gloves and mask, as fumes are nasty

Answered on 08/08/2012 by LARRY DYER

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HI, I have used this product for many years to cleanup my boat at the end of the season, my boat stays in the water all summer•À_?_ Very good product. You have just to spread the product on the boat hull, waits for 5 minutes and scrubs with a brush with long hair and water it after that•À_?_ in my case, I have a boat of 18 feet and I am done in 20 minutes•À_?_ Make sure to clean your boat when there is no wind and wears very old clothes, the stuff can burn your clothes•À_?_ Daniel

Answered on 08/09/2012 by DANIEL LEDUC
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Question

After using On & Off on the sides and deck should you put on a wax?

Asked on 04/25/2012 by Undisclosed

Top Answer

I have used ON-Off for a number of years and it is a great product as I'm sure you are aware since your question is after use. Since my boat has a clear coat I have not spent the time waxing but I believe it would reduce drag and improve speed. I leave our fiberglass pontoon in the water during the summer and not sure if it would help but it would not hurt. Sorry I could not be more specific. Art

Answered on 04/27/2012 by BRANNON ARTHUR
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I used the cleaner with great success. To make the hull slippery through the water and to make it easier to clean next time, I polished, then waxed and buffed the hull.

Answered on 04/26/2012 by CHRISTOPHER SHORT

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You can normally wax after using ON-Off. It will certainly have removed any wax along with stains. However, a good rule is never to put wax on any surface of your deck that you may walk on - it makes it slippery.

Answered on 04/26/2012 by DAN ZEITLIN

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Absolutely

Answered on 04/25/2012 by LEO KYRIA

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Yes I would after a through wash and rinse

Answered on 04/25/2012 by ARCHIE MAGGARD
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Question

Will this clean Aul.?

Asked on 09/13/2011 by Undisclosed

Top Answer

I am a big fan of On-Off Hull and Bottom Cleaner; it is corrosive, so one needs to take the proper precautions when using it, but i haven't found anything yet that On-Off won't clean from my hull. My problem in answering A Shopper's question is that I have no idea what Aul. is...

Answered on 09/13/2011 by JOHN FLOOK
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Spoke to West Marine about On-Off and was warned that if used while the boat is on the trailer, be careful as the product is corrosive to Aluminum/

Answered on 10/01/2011 by bruceschneider21 b

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Not sure what you mean by "AUL" ?

Answered on 09/13/2011 by PHILIP BURTON

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I dont know, I used it on fibergalss hull stains from fuel and it too it right off and made the hull bright white. i

Answered on 09/13/2011 by ROSARIO SAFINA

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no experience on aluminum but it was great on gelcoat. Worked as advertised no complaints

Answered on 09/14/2011 by MICHAEL KENOSH
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Question

Can it be used on travertine stone?

Asked on 01/04/2013 by earl macey

Top Answer

I have only used it on boat hulls and have not have any concerns with damaging the fiberglass.

Answered on 01/07/2013 by WILLIAM MASTORIS
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Earl, I have seen muratic acid remove/dissolve hard water deposits from concrete. I'm not sure but the on-off bottom cleaner may be too strong to begin with. The cleaner contains muratic (hydrochloric) acid and phosphoric acid. These are two of the top 10 strongest acids available . I would try the muratic acid solution found at pool cleaning supply stores. Muratic acid is less expensive and is sold by the gallon. Make sure you try it in an "inconspicuous place" first and dilute it prior to use. It will probably etch the stone surface and leave a white chalking/residue but this should wash off and provide a nice clean surface. Whatever you do - do not get this stuff in your eyes. Chris

Answered on 01/08/2013 by CHRISTOPHER SHORT

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Earl, Hey there. I have never used On-Off Hull and Bottom Cleaner on travertine pavers or stone. I use it on my boat and I can tell you that it is an amazing product. I spray it on with a pump sprayer and hose it off. Off come the algae from the river. You might want to try a little bit on the small section out of the way. The cleaner smells as though it has a high level of muriatic acid in it (it will take your breath away if you get a wiff), and it will likely brighten up the surface. I could not swear that it wouldn't damage it. John

Answered on 01/07/2013 by JOHN HEATON

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Earl, I haven't used it on travertine, but used it on ceramic swimming pool tile. Spray it on, let it foam, brush if necessary, rinse, then repeat until it doesn't foam. Rinse well and neutralize with baking soda. Since the grout is softer, be sure to work fairly fast and rinse well. Good luck!

Answered on 01/08/2013 by DON BURTS
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