Starting to prep the bottom for the seasons paint job. I have a very stubborn water line stain that I haven't been able to remove. I the past I've used Mary Kate and some other products with success but this time they aren't working. Any suggestions are appreciated. Thanks in advance, Joe Mullee
Stubborn Water Line Stains
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high potency solutions
The best is probably oxalic acid. Turns gelcoat white and fixes rust stains. Muriatic acid (HCl) probably second best, essentially very concentrated bleach. Clears up pesky, hardened slime and eats away at barncle bases. Not nearly as good as oxalic at clearing rust stains, but it is at least available at any hardware store. Oxalic seems to be a little harder to find. On & Off is a namebrand product that takes care of all this; I'm not sure if either of the above is an ingredient but my guess is one of them is (probably oxalic).
The best is probably oxalic acid. Turns gelcoat white and fixes rust stains. Muriatic acid (HCl) probably second best, essentially very concentrated bleach. Clears up pesky, hardened slime and eats away at barncle bases. Not nearly as good as oxalic at clearing rust stains, but it is at least available at any hardware store. Oxalic seems to be a little harder to find. On & Off is a namebrand product that takes care of all this; I'm not sure if either of the above is an ingredient but my guess is one of them is (probably oxalic).
If oxalic doesnt do the job.....
Begin again and 'soak' the stain with a highly caustic detergent .... lye soap or a detergent containing sodium silicate, etc. This will usuallly remove oil scum from someones blown bilgetank. Once the oil residue is removed, then try again with oxalic and if that doesnt work ....... Take the saturated oxalic mixture, pour it onto paper towels and 'seal' them to the hull by covering with saran wrap, tape the edges of the saran .... and let soak for a few days. Use caution with oxalic so it doesnt harm your kidneys, etc. as it rapidly absorbs through bare skin. alternatively ... try HOT oxalic acid (with the obvious caveats of due diligence to personal protection: chem gloves, goggles, full chem apron, etc. ) Late last season there was a LOT of 'bilge mousse' on the Ches.bay .... I had a dickens of a time removing it when I hauled.
Begin again and 'soak' the stain with a highly caustic detergent .... lye soap or a detergent containing sodium silicate, etc. This will usuallly remove oil scum from someones blown bilgetank. Once the oil residue is removed, then try again with oxalic and if that doesnt work ....... Take the saturated oxalic mixture, pour it onto paper towels and 'seal' them to the hull by covering with saran wrap, tape the edges of the saran .... and let soak for a few days. Use caution with oxalic so it doesnt harm your kidneys, etc. as it rapidly absorbs through bare skin. alternatively ... try HOT oxalic acid (with the obvious caveats of due diligence to personal protection: chem gloves, goggles, full chem apron, etc. ) Late last season there was a LOT of 'bilge mousse' on the Ches.bay .... I had a dickens of a time removing it when I hauled.
Duro Stain Remover.
I have tried this on some fenders. It took the stain out It does contain phosphoric acid. just something I tried. If it is a stain, maybe your bottom paint should come up higher. I raised my bottom paint line up two inches. It is nice not having to deal with that algae stain. r.w.landau
I have tried this on some fenders. It took the stain out It does contain phosphoric acid. just something I tried. If it is a stain, maybe your bottom paint should come up higher. I raised my bottom paint line up two inches. It is nice not having to deal with that algae stain. r.w.landau
If you need a "highly caustic" cleaner
try "easy-off oven cleaner" Almost all soaps are salts of fatty acids and sodium hydroxide. But rather than re-inventing the wheel, the cleaners used by the auto detailers are as safe and effective as anything you are likely to want to use.
try "easy-off oven cleaner" Almost all soaps are salts of fatty acids and sodium hydroxide. But rather than re-inventing the wheel, the cleaners used by the auto detailers are as safe and effective as anything you are likely to want to use.
cheseapeake bay beard removal
I don't know where shady side, md is? but it sounds like that you have what is affectionately called chesie bay beard. its basically an iron stain, which is very predominate in the northern bay. believe it or not at one time they actually mined iron ore near the mouth of middle river and the mouth of the Patapsco. a lot of this iron laden water also comes out of the susquehanna river which orig in the up state pa mining regions. oxalic acid (aka) hull stain remover works wonders. I have used it many times over the years and it won't harm gell coat. i believe its made by boat soap people and available at most marine supply stores. this acid is organic in nature, but be sure to get it all rinsed off after use. if its really bad you may have to use it full strength and multiple times to get it all dissolved.. S/V Que Pasa?
I don't know where shady side, md is? but it sounds like that you have what is affectionately called chesie bay beard. its basically an iron stain, which is very predominate in the northern bay. believe it or not at one time they actually mined iron ore near the mouth of middle river and the mouth of the Patapsco. a lot of this iron laden water also comes out of the susquehanna river which orig in the up state pa mining regions. oxalic acid (aka) hull stain remover works wonders. I have used it many times over the years and it won't harm gell coat. i believe its made by boat soap people and available at most marine supply stores. this acid is organic in nature, but be sure to get it all rinsed off after use. if its really bad you may have to use it full strength and multiple times to get it all dissolved.. S/V Que Pasa?
On/Off is a good product...
...but try a hint I read in SAIL mag a few years ago, first. I read that straight lemon juice will work on the stains. It is just the chemical balance of the water that causes discoloration and the acidic lemon juice will cut it right out.
...but try a hint I read in SAIL mag a few years ago, first. I read that straight lemon juice will work on the stains. It is just the chemical balance of the water that causes discoloration and the acidic lemon juice will cut it right out.
On/Off is good stuff...
...but try a hint that I read in SAIL mag a few years ago. Since the waterline is discolored by a chemical imbalance of the water, straight lemon juice may do the trick of removal. The acidic lemon juice may cut it.
...but try a hint that I read in SAIL mag a few years ago. Since the waterline is discolored by a chemical imbalance of the water, straight lemon juice may do the trick of removal. The acidic lemon juice may cut it.
Joe
If Mary Kate "On and Off" and the other oxalic acid products mentioned below are not working (sometimes it's a function of how long you leave them on before washing them off), you may have to resort to wet/dry sanding. I recently did the waterline and a bit above it on my boat and, while a lot of work (took about 8 hrs), it produced "pretty good" results on a 20 yr old hull. I began with 400 grit paper in a rubber sanding block (Home Depot). Then 800 grit, then finished with 1500. Soak the paper in water first. Fill a spray bottle with water and some dish washing liquid and squirt in on both the paper and the surface to be wet sanded at it keeps the paper from clogging and lubes the surface. Good luck.
If Mary Kate "On and Off" and the other oxalic acid products mentioned below are not working (sometimes it's a function of how long you leave them on before washing them off), you may have to resort to wet/dry sanding. I recently did the waterline and a bit above it on my boat and, while a lot of work (took about 8 hrs), it produced "pretty good" results on a 20 yr old hull. I began with 400 grit paper in a rubber sanding block (Home Depot). Then 800 grit, then finished with 1500. Soak the paper in water first. Fill a spray bottle with water and some dish washing liquid and squirt in on both the paper and the surface to be wet sanded at it keeps the paper from clogging and lubes the surface. Good luck.
How picky is the Misses?
Joe, if you have a better half who insists there is only one proper way to paint the boat, you'll just have to keep scrubbing. Aesthetics are nice, but there's a point where "Let's go sailing" has to happen. CLR and some of the other "calcium and lime stain" type removers work well for iron stains too, but if the old paint was porous and something really got into it, or you just run out of elbow grease, it may be simpler to just clean it as best you can, and then paint over it. Either raise the bottom paint or add a boot stripe--because boot stripe paint is especially meant to be in that wet zone, it is more durable than the topside paint or old porous gelcoat higher up on the boat. And if you don't like to paint, check out 3M's vinyl boot stripe tapes. Exterior grade vinyl that typically lasts 5-10 years without problems, goes on just like masking tape, can hide a lot of sins.<G>
Joe, if you have a better half who insists there is only one proper way to paint the boat, you'll just have to keep scrubbing. Aesthetics are nice, but there's a point where "Let's go sailing" has to happen. CLR and some of the other "calcium and lime stain" type removers work well for iron stains too, but if the old paint was porous and something really got into it, or you just run out of elbow grease, it may be simpler to just clean it as best you can, and then paint over it. Either raise the bottom paint or add a boot stripe--because boot stripe paint is especially meant to be in that wet zone, it is more durable than the topside paint or old porous gelcoat higher up on the boat. And if you don't like to paint, check out 3M's vinyl boot stripe tapes. Exterior grade vinyl that typically lasts 5-10 years without problems, goes on just like masking tape, can hide a lot of sins.<G>
FSR
Fiberglass stain remover is a product that I had good luck with. It's a blue goo. Glop it on. LET IT SIT for 10-15 minutes on tough stains. Scrub and rinse.
Fiberglass stain remover is a product that I had good luck with. It's a blue goo. Glop it on. LET IT SIT for 10-15 minutes on tough stains. Scrub and rinse.
wood bleach
I used a product from Sherwin Williams Paint Store called wood bleach. Costs about $7 per container, mixed in a one gallon sprayer, and was more than enough to do my Catalina 22.
I used a product from Sherwin Williams Paint Store called wood bleach. Costs about $7 per container, mixed in a one gallon sprayer, and was more than enough to do my Catalina 22.
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