Anyone know how to remove stain from Hull?

[osins74]

So originally posted in my Fall cleaning thread and need help removing the hull stain in the picture. I used Starbrite Instant Hull Cleaner and it removed most of the stains, but just can’t remove this last line. I have no idea what it is? Any advice is greatly appreciated.

 

[Canuckjetboater]

@osins74 ......having worked with gel coat for many years I always start with the least aggressive procedures and work my way up. This looks to me like hard water build-up at the waterline. I would start by sponging on a mineral remover like CLR or even a 5% solution of vinegar and let it sit for a few minutes then try wiping it off. If that didn't work I'd do the same thing and let it sit longer with a couple of re-applications and try wiping that off. Next I'd do the same thing and then scrub it a bit harder with a cloth. Next I'd try some stronger hull cleaner like Starbright. This looks more like a mineral "crud" build-up so I'd start easy so as to not dull your gel coat finish. Afterwards I'd wax and polish the waterline area. I like hand applied Meguiar's Gold Marine Wax (black bottle). I apply and buff by hand. Apply the product and let it do the work.

 

[ndwiginton]

Have you tried compounding the boat hull? I believe it should take care of it but you will need to make sure you put a coat of wax/polish back on it afterwards.

 

[CigarJeff68]

I use toilet bowl cleaner on the white parts of our hull. I've used both Sno Bol, and Clorox with out bleach, and both have worked very well.

 

[anmut]

x2 for toilet bowl cleaner. Use gloves on your hands and a clean cloth. Put on the cloth, wipe on, let sit, rinse off. Rewax that part though as the TB cleaner contains acid.

 

[Canuckjetboater]

Have you tried compounding the boat hull? I believe it should take care of it but you will need to make sure you put a coat of wax/polish back on it afterwards.
[/QUOTE
@ndwiginton ....definitely a possible solution but I respectfully suggest a several steps before compounding because, even with the least abrasive compounds, you only get to do so many before you burn through your gel coat and compounding a mineral or vegetative surface material can just compound it into the gelcoat so I like to remove it first then if there is a hazing due to UVA/B degradation then I compound and wax. my 2 cents.

 

[Beachbummer]

Robot or human?

This is a cheap one to try. It's extremely effective on stains like this (or it has been for me) Worst case if it doesn't work it was cheap and you can use it for many things. It vanishes my water stains after sitting for a minute in place. Best of Luck!

 

[osins74]

Thanks everyone for your responses, so I’m going to pickup a spray bottle of the starbrite instant hull cleaner, it’s seems that it’s more of a gel and hoping it will stay on the area. I’ll also pickup some toilet bowl cleaner without bleach and try that if the starbrite doesn’t work. I’m assuming a magic eraser is not recommended on the gel coat, too abrasive?

 

[Five Faces]

If/when nothing above works go right to the heavy duty stuff, MaryKate On&Off. They make a gel as well if that is your preference. Simply apply to the area, let it sit for a few minutes, and power wash it off, no scrubbing required. One word of caution, it is nasty stuff so wear PPE, and cover trailer if galvanized, painted trailer should be okay just rinse very thoroughly.

 

[osins74]

Thanks @Five Faces, I will give that a try. My local boat shop has CRC On & Off Boat Hull and Bottom cleaner, purple bottle. Is that the same product? If so I will pick one up tomorrow.

 

[212s]

@osins74 ......having worked with gel coat for many years I always start with the least aggressive procedures and work my way up. This looks to me like hard water build-up at the waterline. I would start by sponging on a mineral remover like CLR or even a 5% solution of vinegar and let it sit for a few minutes then try wiping it off.

Yup I like vinegar for cleaning, it's safer to use, it's very cheap, and works great on water/mineral deposits.

 

[Five Faces]

Thanks @Five Faces, I will give that a try. My local boat shop has CRC On & Off Boat Hull and Bottom cleaner, purple bottle. Is that the same product? If so I will pick one up tomorrow.

I believe MaryKate is made by CRC, but I’m not familiar with the purple bottle. Here is what I have used.

Amazon.com : MaryKate MK2032 Marykate On & Off Hull & Bottom, 32 fl oz : Boating Cleaners : Sports & Outdoors

Amazon.com : MaryKate MK2032 Marykate On & Off Hull & Bottom, 32 fl oz : Boating Cleaners : Sports & Outdoors

www.amazon.com

 

[osins74]

I believe MaryKate is made by CRC, but I’m not familiar with the purple bottle. Here is what I have used.

Amazon.com : MaryKate MK2032 Marykate On & Off Hull & Bottom, 32 fl oz : Boating Cleaners : Sports & Outdoors

Amazon.com : MaryKate MK2032 Marykate On & Off Hull & Bottom, 32 fl oz : Boating Cleaners : Sports & Outdoors

www.amazon.com

This is the one I was referring to;

 

[Five Faces]

This is the one I was referring to;

A quick search leads to believe that this CRC On&Off is the Canadian version of the MaryKate On&Off. Again it is very aggressive acid, so be sure to wear gloves, glasses, mask, etc.

 

[Canuckjetboater]

Thanks everyone for your responses, so I’m going to pickup a spray bottle of the starbrite instant hull cleaner, it’s seems that it’s more of a gel and hoping it will stay on the area. I’ll also pickup some toilet bowl cleaner without bleach and try that if the starbrite doesn’t work. I’m assuming a magic eraser is not recommended on the gel coat, too abrasive?

@osins74 Majic Eraser used to have formaldehyde in it which can yellow materials. There were other chemicals too that i would not use on boat gel coats or seat "vinyls" . Have heard reports that it worked "great" on boat seats then months later the areas cleaned started to yellow.

 

[Beachbummer]

Oxalic Acid is one ingredient (also in the barkeepers friend) that just vanishes the stains after about a minute of application. It's the main ingredient in a few of the cleaners. I think it takes any wax off, sad it is somewhat intense.

 

[Canuckjetboater]

Oxalic Acid is one ingredient (also in the barkeepers friend) that just vanishes the stains after about a minute of application. It's the main ingredient in a few of the cleaners. I think it takes any wax of, sad it is somewhat intense.

@Beachbummer .....Oxalic Acid is indeed very good but as you correctly state (IMO) it has to be used carefully. I can't remember the name of the company that used to market it in a white plastic jar, in white crystal form to be mixed with water to clean the "pinkish" stains etc. that appeared on white "vinyl" marine seats - it was very effective if you didn't leave it on too long and washed-off the seat later!

 

[osins74]

@osins74 Majic Eraser used to have formaldehyde in it which can yellow materials. There were other chemicals too that i would not use on boat gel coats or seat "vinyls" . Have heard reports that it worked "great" on boat seats then months later the areas cleaned started to yellow.

Thanks @Canuckjetboater, didn’t think it was safe but I’m a total newb so though I would ask the question. Going to try and tackle it this evening, will keep you all posted. Weather permitting.

 

[osins74]

Hello everyone, I was able to remove the stain and the product that worked was Starbrite Boat Bottom cleaner. It was a little thicker than the Instant Hulll Cleaner, I spayed some on a micro fiber applicator pad and applied to the line and it wiped off instantly! We could not believe how easy it was compared to the Instant Hull cleaner. Thanks again everyone for all the help and suggestions. Sorry forgot to take an after picture, I’ll get some posted tomorrow.