Berry stains on gecoat

May 2, 2014
76
Hunter 26 Home port Cape Coral
Ouch! Opa spent the summer in south west Florida on canal lift.
Didn't really notice Washintonian Palm. Berries dropped and dried, baked on.
Anybody have any experience cleaning this mess.
 

Attachments

ALNims

.
Jul 31, 2014
208
Hunter 356 Huis Ten Bosch Marina, Sasebo, Japan
Try acetone. I have cleaned up all kinds of stuff on my gelcoat with no damage to the gelcoat.
 

BrianW

.
Jan 7, 2005
843
Hunter 26 Guntersville Lake, (AL)
A solution of oxalic acid (wood bleach). This is available at big box home improvement stores. This is the active ingredient in boat hull waterline stain cleaner.
 
May 2, 2014
76
Hunter 26 Home port Cape Coral
A solution of oxalic acid (wood bleach). This is available at big box home improvement stores. This is the active ingredient in boat hull waterline stain cleaner.
Brian
Tried a solution West Marine had that's active ingredient was oxalis acid.
Didn't work. Will find a stronger solution (Home Depot) see if that's better.
Than Mary Kate, Acetone. Hope something works.
 

ALNims

.
Jul 31, 2014
208
Hunter 356 Huis Ten Bosch Marina, Sasebo, Japan
I have been able to take all stains off with acetone. Good luck and let us know what worked best.
 
Nov 6, 2006
10,050
Hunter 34 Mandeville Louisiana
Time or a bleach will remove that.. if you use a chlorine base bleach, be very careful to rinse thoroughly and don't get any on stainless parts, like swedged fittings. A strong hydrogen peroxide will take it out as well. (Baquasil or equivalent shock from swimming pool store. Read the warnings before playing with it)
 
Jun 16, 2010
495
In search of my next boat Palm Harbor, FL
As a last resort you can use toilet bowl cleaner, but don't let it sit long on the gelcoat. Squirt, wipe, wash < 1min. Wash thoroughly with soapy water, and depending on where you are using it you may want/have to re-wax after.
 
Aug 27, 2014
25
Sabre 34 53447 Sarasota
This old post was most helpful. My foredeck was bombed with berries while I was away for several weeks. I’m also on the SW Florida Gulf Coast. Tried several stain cleaners and finally Tilex Mold & Mildew (with lots of scrubbing) got it off.
Thanks for the dialog.
 

RoyS

.
Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
My wife frequently spills red wine on the deck. Sunlight seems to clear it up in a few days.
 
  • Like
Likes: Bob S
Jun 8, 2004
10,376
-na -NA Anywhere USA
As a dealer I had to keep old and new sailboats clean. Once getting the stain off,wax the boat with two coatings of pure wax.

Being retired I sure don’t miss that at all!
 
Jun 8, 2004
10,376
-na -NA Anywhere USA
As a dealer I had to keep old and new sailboats clean. Once getting the stain off,wax the boat first and then apply two coatings of pure wax.

Being retired I sure don’t miss that at all!
 
Apr 22, 2015
16
newport holiday 20 Tennessee river
berry stains are broken down with lemon juice or vinegar. take slice lemon and lay it on stain for five minutes, take Mr Clean magic eraser preferably with warm water and drop or two of dawn dish soap and scrub. The magic eraser is just as important as the lemon juice. Hope it helps
 
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
A solution of oxalic acid (wood bleach). This is available at big box home improvement stores. This is the active ingredient in boat hull waterline stain cleaner.
:plus: It is also the active ingredient in barekeeper's friend.

1665503201967.png


It is like magic on tannin stains. Put a dab on the stain and let it sit a day.
 
Sep 24, 2018
3,275
Catalina 30 MKIII Chicago
berry stains are broken down with lemon juice or vinegar. take slice lemon and lay it on stain for five minutes, take Mr Clean magic eraser preferably with warm water and drop or two of dawn dish soap and scrub. The magic eraser is just as important as the lemon juice. Hope it helps
:plus:
This with the addition of baking soda, is how we get my 44 year old boat looking like new. The dish soap acts as a lubricant and makes the sponge last longer. Applying even pressure on the sponge makes it last the longest. Magic erasers are slightly abrasive so I'd be hesitant to use it on a new boat
 
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
:plus:
This with the addition of baking soda, is how we get my 44 year old boat looking like new. The dish soap acts as a lubricant and makes the sponge last longer. Applying even pressure on the sponge makes it last the longest. Magic erasers are slightly abrasive so I'd be hesitant to use it on a new boat
The acid in lemon (citric) and vinegar (acetic) are both chemically similar to oxalic acid. Magic eraser uses melamine. It is a base that neutralizes the acid and also acts as a mild abrasive. Baking soda is also a mild base that acts as a mild ebrasive. So a follow up treatment with magic eraser and/or backing soda is a good idea to "kill" the acid once you think it is done doing its job. If you have rust stains, both citric and oxalic will do a good job. They are both capable of "chelating" the iron +3 ion in rust and thus making the "rust" water soluble. Acetic acid is better for hard water scale than the other two but is not as effective on rust stains. Similarly all three acids are effective at breaking down tannins... which are responsible for most of the brown scum stains you get in your gel coat. My personal experience has been that water scum stains are best addressed with oxalic acid but all three work to some extent.


For the nurds on here... I posted the structures of the three acids below. The points in the structures represent carbon atoms and I colored them in for the first structure. I also made a representation of citric acid losing its acidic protons and then chelating an iron ion.


Citric:
1665591273650.png


Oxalic:
1665590547163.png


Acetic:
1665590580044.png