Replies

1. 
   DanH | Jan 10, 2009 04:54am | #1

   Good luck! It's pretty darn hard to clean a FG boat.

   God is REAL, unless explicitly declared INTEGER
1. 
   CharlesLauzon | Jan 15, 2009 11:18pm | #24

   Yeah, the toilet bowl cleaner could be an alternative, maybe try Lysol Extra strength, but be careful, that stuff can burn wright trough your clothes and skin.

2. 
   Scott | Jan 10, 2009 05:38am | #2

   Ya, what Dan said.

   If it's a nice boat I'd be tempted to rough it up with a RO sander and roll on a fresh coat of Gelcoat.

   Scott.

3. 
   JHOLE | Jan 10, 2009 05:44am | #3

   Muriatic - diluted.

   Toilet bowl / bath cleaner.

   Then abrsive compounds - rubbing compound, glaze.

   Stay away from miracle fixes like penetrol.

   Some of the staining may never come out, Fiberglass/polyesters are not waterproof.

   Remodeling Contractor just on the other side of the Glass City

1. 
   klhoush | Jan 10, 2009 06:15am | #5

   Fiberglass/polyesters are not waterproof.

   How can water pass through fiberglass? Are there pores? Is the resin water soluble?

1. 
   DanH | Jan 10, 2009 07:12am | #10

   The outer surface is not fiberglass but gelcoat which is a sort of filled epoxy material. It is reasonably impervious to water, but does get stained.
   God is REAL, unless explicitly declared INTEGER

2. 
   bldrbill | Jan 10, 2009 04:54pm | #11

   Thanks for all the great suggestions.  I'm going to get the boat off the trailer and turn it upside down in the yard so I can get at it without lying on my back.  I'll then try the various things to see what works.  I'm hoping to have some success without resorting to abrasives and new gelcoat.  It's raining here now, so I'll work on it next week.  I'll try to post some pics.  Bill 

1. 
   RobWes | Jan 10, 2009 05:08pm | #12

   Go to the marine store and get a bottle of ON-OFF cleaner. It might help. Asotone will not hurt a thing, I use it on my own boat. What you have is staining, there may be nothing you can do other than to lightly sand the boat to the water line and bottom paint it. If there are others areas of neglect then painting the entire boat may be your only way out. This can be done with off the shelf products also available from your local marine store.

   Lastly let me remind you that boat really is an acronym of Break Out Another Thousand.

1. 
   DanH | Jan 10, 2009 07:39pm | #17

   Yeah, a boat's a hole in the water that you throw money into.
   God is REAL, unless explicitly declared INTEGER

2. 
   BillHartmann | Jan 10, 2009 05:44pm | #13

   Actually you might have made it harder with the pressure washer.There are lots of mineral products on the built up and acid will take them off an releasing the other stuff. The one time I pressure washed it was much harder to get the remainder off.Any way I recommend StarBrite Hull Cleaner. Wally World has it.It has oxalic acid in it and it great for stain remove. It is the same active ingredient as in Bar Keepers Friend..
   William the Geezer, the sequel to Billy the Kid - Shoe

1. 
   bldrbill | Jan 10, 2009 06:23pm | #14

   The pressure washer mainly knocked off some fairly loose greenish mossy crud. The other discolorization seems to have worked its way into the gelcoat, I guess from the boat having sat in the water so long.  Thanks for the input, I'll try the cleaner.

1. 
   Karl | Jan 10, 2009 06:41pm | #15

   I have left my boat in the harbor without bottom paint for several months at a time and had extensive bottom growth and staining.My helper has a lot of autobody experience and managed to restore the hull to a like new finish with automotive buffing compound.Later I read about a product called Mary Kate Bottom Cleaner that is alleged to work great. It sounds like the starbright mentioned in a previous post. I recall several warning about not using it with the boat on a trailer as it will etch the finish.I would consider trying oaxalic acid or muriatic acid if you didn't want to buy a commercial cleaner.Depending on how nice the boat is you could buff it out with rubbing/polishing compound and wax it. I have had really good luck with a 3M wax that has teflon added to it.Karl

2. 
   Matt | Jan 12, 2009 12:15am | #18

   Be careful about using cleaners like Comet on gelcoat.  It will damage the appearance of the gelcoat.  Best to stick with cleaners that are specifically for that purpose.

   The thing about no Comet, Ajax, etc on fiberglass tubs is part of my standard spiel I give during my "New Home Orientation" talk I give homebuyers.

   I'm also speaking as a person who has owned several fiberglass boats.

3. 
   bldrbill | Jan 12, 2009 01:14am | #19

   I picked a bottle of the Starbrite hull cleaner recommended by BillHartmann and tried it on a small area and it seems to work fairly well.  Most of the discoloring comes off but some remains.  I'll get the boat flipped in a few days and give it a real test.  Seems pretty good so far.  Bill

4. 
   Snort | Jan 12, 2009 03:45am | #20

   I picked up a sail boat like that. Star Brite got most of it. The rest is under water anyhow.When we get a fiberglass fishing boat full of blood stains, there's nothing like a good pelting rain for cleaning. Maybe a nice blood bath?http://www.tvwsolar.com

   I went down to the lobby

   To make a small call out.

   A pretty dancing girl was there,

   And she began to shout,

   "Go on back to see the gypsy.

   He can move you from the rear,

   Drive you from your fear,

   Bring you through the mirror.

   He did it in Las Vegas,

   And he can do it here."

3. 
   TheWgroup | Jan 15, 2009 05:34am | #21

   Use a product called On/Off it is specifically designed for boats and will def take most stains out. It is very toxic and needs to be applied carefully in a well ventilated area. Wear a respirator. I live on the coast of SC and our boats get stained easily in the saltwater. On/off will get it clean when others want. Boater' World and West Marine will have it

1. 
   bldrbill | Jan 15, 2009 06:24pm | #22

   I've already used Star Brite on it and got most of it off.  I'll try the on/off and see if it will get the rest.  Star brite contains oxalic acid.  Do you know what's in the on/off?

1. 
   RobWes | Jan 15, 2009 07:12pm | #23

   I believe it's the same stuff with a different name.

4. 
   brucet9 | Jan 10, 2009 05:49am | #4

   I wonder, if the staining is not very deep, whether wiping with acetone would get it?

   Do you have access to a jeweler's loupe so you can see how deep the stain is?

   BruceT
5. 
   alwaysoverbudget | Jan 10, 2009 06:22am | #6

   try clorox first,cheap and easy

   try the muratic acid, if that don't work go to plan c.

    

   take about 600 grit wet or dry and wet sand the discoloring off,then use a buffer and rubbing compond to polish the scratches out. the gel coat is usally about 1/16 thick so you have quite a bit to work with.

   YOU ONLY NEED TWO TOOLS IN LIFE - WD-40 AND DUCT TAPE. IF IT DOESN'T
   MOVE AND SHOULD, USE THE WD-40. IF IT SHOULDN'T MOVE AND DOES, USE THE
   DUCT TAPE.

6. 
   MrBill | Jan 10, 2009 06:29am | #7

   Bill,

    Before you ruin it with all these homegrown ideas, go to a local marine store and see what they recommend. I know they have products specifically for this use and there is a lot better chance they will not hurt the hull.

   Bill Koustenis

   Advanced Automotive Machine

   Waldorf Md

7. 
   Ted W. | Jan 10, 2009 06:54am | #8

   I recommend X-14 to my customers for cleaning moldy showers. Stuff really works great, and might be just the solution for your boat. However, if you try this route make sure to get the Mold & Mildew Stain Remover. There is another one called Bathroom Cleaner, which looks the same but is not nearly as tuff.

   http://www.x14brand.com/products/mold-mildew-stain-remover/

    

    

   View Image

8. 
   DanH | Jan 10, 2009 07:11am | #9

   Do be careful with abrasives. The gelcoat isn't all that thick and even if you don't rub all the way through it you'll get "ghosting" from the fiberglass behind it if it gets too thin.

   God is REAL, unless explicitly declared INTEGER
9. 
   wallyo | Jan 10, 2009 07:36pm | #16

   I have not read all the posts don;t know if this will work but I use it on fiberglass tubs just cleaned the 4'x6' tub this way. A green 3M sponge and gel soap for auto dishwashers.

   Wallyo