Marine growth....how to clean off?

[Manipulator]

I have some funk growing on the bottom of my boat. This is some fresh water crude. Last year I left my boat in the water for six months and it grew some crude on the hull but nothing like this and this stuff was a half inch of nasty filth that grew in two weeks! Lake must have some weird stuff in it this year. It is a black funk. My boat would hardly go and they looked at it and it was from this gunk on the hull. They power washed it but some of it is still attached. It looks like black spider webs all over the bottom. This stuff is ruff to the touch. <br /><br />I need to pull the boat out and somehow get this stuff to loosen so I can blast it off. Any suggestions? Bleach and water (heard this is not a good idea), how about straight lemon juice? I read somewhere that helps. Marina said to buy "lime away" and spray it on there and let it sit and then blast it off. Called it an acid wash which they don't do at this specific marina. I wouldn't imagine that is good for the gel coat.

 

[crazy charlie]

Re: Marine growth....how to clean off?

Get an pump up garden sprayer and buy a few bottles of the cheapest toilet bowl cleaner you can find at Walmart.Wet the bottom with a garden hose and then spray the toilet cleaner on.Let it sit for several minutes and then try rubbing a broom or a scrub brush on a broom stick on the fouled areas and then hit it with the pressure washer again or a garden hose.This is the cheapest effective way to clean it up.The best way is to buy some On-Off at the marine store which is similar to the bowl cleaner but the On-off is the absolute best.Wear protective gloves and goggles when you use any of this stuff and when you are done you will want to antifoul paint your bottom to prevent this problem again.Charlie

 

[bayman]

Re: Marine growth....how to clean off?

Usually these products are called hull cleaners or bottom cleaners. The Star Brite brand, from what I have seen, is one of the good ones.<br /><br /> http://www.iboats.com/mall/index.cgi?keywords=bottom+cleaner

 

[bayman]

Re: Marine growth....how to clean off?

Interesting, I haven't tried toilet bowl cleaner. If you leave your boat in the water for extended periods, I definitely agree with antifouling the bottom, like Charlie says.

 

[Manipulator]

Re: Marine growth....how to clean off?

I leave it in 6 months but now am thinking of just taking it out and putting it on the trailer when I leave. Toilet bowl cleaner....hmmmm interesting, I may try that. Don't want to antifoul the bottom as then you have to continue to have it painted, plus it's not in the water year round. I just want to get her nice and clean and then start putting it on the trailer.

 

[craze1cars]

Re: Marine growth....how to clean off?

Do you have hard, crusty, off-white/yellowish lime-like deposits? After you try all of above and get tired of scrubbing your arms off for one square foot of clean boat, make the switch over to 1 part muriatic acid, 3 parts water, long rubber gloves, safety goggles, wear old clothes and apply with old rags (they might dissolve after a while.) It'll hiss, smoke, and bubble (work outside and don't breathe the fumes) but the boat will clean up real easy. It can be pretty caustic to work with, and needs to be followed up by a LOT of fresh water rinsing and then a polish & wax to bring the shine back and get the stain outta the gel. When mixing it up, always dump the acid in the water...not the water in the acid (very dangerous).

 

[Manipulator]

Re: Marine growth....how to clean off?

Do you have hard, crusty, off-white/yellowish lime-like deposits?<br /><br />yep, sure do and its on there! That in addition to the black crap growing on there. <br /><br />After you try all of above and get tired of scrubbing your arms off for one square foot of clean boat, make the switch over to 1 part muriatic acid, 3 parts water, long rubber gloves, safety goggles, wear old clothes and apply with old rags (they might dissolve after a while.) It'll hiss, smoke, and bubble (work outside and don't breathe the fumes) but the boat will clean up real easy. It can be pretty caustic to work with, and needs to be followed up by a LOT of fresh water rinsing and then a polish & wax to bring the shine back and get the stain outta the gel. When mixing it up, always dump the acid in the water...not the water in the acid (very dangerous).<br /><br />That sounds like a professional job. Where do I get this acid and how long do you leave it on? Can I put it in a garden sprayer and apply it? What about the lime away stuff? How about toilet bowl cleaner? Lemon juice or bleach?

 

[crazy charlie]

Re: Marine growth....how to clean off?

As I stated before,toilet bowl cleaner works great.On-Off made by Marykate is the absolute best!! Bar none!! Not much effort needed with the brushing.Charlie

 

[Ironmike]

Re: Marine growth....how to clean off?

I to have used the toilet bowl cleaner in past years. But here in Canada they have stopped selling the more caustic kind that worked well. In a trial this year I used delimer the kind you can pick up anywhere I put a quart of it + a cup of general purpose cleaner mixed with a couple gals of water. Brushed it on with truck wash brush & to my amazment the gunk just rinsed off with garden hose. Even more amazing is that the next time I took the boat out it was still clean, first time in several yrs that I have ever seen that.

 

[rogerwa]

Re: Marine growth....how to clean off?

I just used the ez on/off this spring and it did a good job. Be carefull using it though as your nostrils will burn if you inhale it.<br /><br />The stuff on my boat sounds pretty much like what you are experiencing and it worked well.<br /><br />BTW don't spill any on you vehicle carpet as it will burn right through it. Don't ask me how I know.

 

[craze1cars]

Re: Marine growth....how to clean off?

Originally posted by Manipulator:<br /> <br />That sounds like a professional job. Where do I get this acid and how long do you leave it on?

Not a professional job, but just have respect for the fumes and the possibility of burning your skin a bit. And don't splash it in your eyes or you'll really feel it. Muriatic acid is readily available in large quantities at any local hardware store. It's a very popular acid that often is used in home swimming pools to lower the water's PH. Also commonly used to etch bathtubs for refinishing, and to clean concrete floors for prep for the same. I haven't bought any in a while, but it's probably $5 a gallon or something cheap like that.<br /><br />My method is to dilute it 1 to 4 with water (you can use it stronger than that if you want, and might want to if you have a really thick crust on the hull, but the fumes become a bit overpowering and the danger factor increases), then just take an old towel, soak it, and rub the dripping towel on the crusty hull. Rub the spot until it burns the crust off. Keep a hose handy to spray the hull down when it feels smooth, and to spray yourself down in case you splash a bit and you start to feel a bit of a burn on your skin. It won't melt you, but it'll start to itch/burn a little like a rash if you splatter it on your body. Just flush it with cold water from the hose and it totally neutralizes...won't even hurt your lawn if you keep plenty of fresh water flowing. IT CAN damage a concrete driveway if you leave it on too long, so just hose the drive down when you're done or if you accidentally spill some from the bucket.<br /><br />A lot of marinas use muriatic acid to clean hulls at the end of every year. It's fast and easy. I've tried many other methods, and I've found this to work far better than any other. For some reason it seems to scare people so many don't try it. Works great.

 

[prockvoan]

Re: Marine growth....how to clean off?

Boat yards use the acid wash.Problem with that is if you have the boat on the trailer,you might not have a trailer after the acid wash.<br />You can buy muriatic acid at any home depot or lumber supply(use for cleanning bricks after lay up or pool supply company.Cost around $4.00 gal.What they sell is a 28% pure,not 100%.Yes,when mixing it with water,add it to water,not the other way.It will smoke and heat up a little,no big deal,just don't breath the fumes.Wear saftey gear,work outside in the open.Have some bakensoda on hand,if you get some acid on you ,throw some bakensoda on it.

 

[craze1cars]

Re: Marine growth....how to clean off?

Prockvoan has a good point...I did it with boat on my trailer...didn't hurt it. But I was careful to flush it with the hose when it dripped on the trailer just in case.