What is the best way to scrape a hull?

[diveguy1]

It would be helpful to have a little more information such as the type and size of boat, type of bottom (wood or fiberglass), bottom painted or fiberglass, gelcoated, and what it looks like now (just scum, barnacles, heavy growth, etc).

I have a 1997 Boston Whaler that I keep in the water for much of the summer. The fiberglass boat has no bottom paint on it, and after about a week in the salt water (San Francisco Bay) it gets a light coat of scum on it, 2 weeks heavier scum and some small grassy growth, and in 3 weeks small barnacles will form. So the first key for me is to clean it often to keep cleaning easy.

I put the dive gear on and wait for the tide to be just right so the water is about 5 feet deep under the boat (which is about the deepest it gets at my dock). I can then stand on the bottom and reach up to clean the bottom. If you can't touch bottom it's not a problem though.

I generally use a green scrubby pad, and work in sections at a time using a circular motion like when you're waxing a car. Use the chines on the bottom and visually grid off sections, or clean one vertical quarter at a time so you can get it all. Visibility gets close to zero sometimes when scrubbing, so being able to physically feel the area under the boat helps me (diving by braille). A handled scrub brush is also helpful sometimes, but again if you keep the bottom clean it will all come off very easily and with little scrubbing.

Barnacles are a different story. Those little monsters hold on very tight and can be a real pain to get off and will tear your cleaning pads and hands if you're not careful. You need to carefully scrape or chip them off one at a time.

It's much easier for me to clean the boat in the water than after pulling it out on the trailer. On the trailer I have the trailer skids/bunks to deal with, and I either have to lay on my back and look up to clean the bottom (getting crap all over me in the process), or bend over and get a sore back. I also can't clean where the skids are. It's much faster and I can do a better job in the water.

If your boat is really bad shape, have an expert do it first to get it thoroughly clean, then you can maintain it every few weeks, months, or whenever needed. Your arms will thank you.

Hope this helps!

 

[shawnstam]

to get the big stuff off I use anything from a plastic scraper to a flat Metal Hoe. If you use a Hoe be very carfull with it not to damage the hull. For lighter stuff a big green pad works fine also does very coarse carpet. Carpet takes a little while but works. I would move the boat to clear open water and anchor it and do the work there just so the debri get carried away. If the boat is out of the water presure wash it carefully. Then let it dry. Then go back and start with course sand paper lightly sanding then work your way to fine paper. There is no easy way to do it.

 

[Juno]

Can you tell me size and location? if there is a chance of a strong current, do it at slack tide!

My previous boat I had pulled once every two years. The hauling included a pressure wash that took care of 95% of the crap. It would take me two long days to prep and repaint the hull. The boat was 32' on the waterline with a 12' beam.

Otherwise I would clean the hull in the water.

#1- Have someone around when you do it. I have lost two friends cleaning boats solo. One was a head injury and the other entanglement.
#2 Slack tide if you have any current.
#3 I bought one of those 'two suction cup with a handle for the hull thingies' so I could hold it and still apply sufficient leverage while cleaning. It is very hard to apply pressure to the hull without something to hold on to.
#4 Visibility - I would leave a hull area when the visibility got very reduced and switch to another section.
#5 I used the best grade bottom paints on my boat, so most of my in-water cleaning was more like a mild scrub. Over the ten years I owned the boat, I never could find anything coating wise that adhered to metal parts and kept the growth off. So, metal parts required scraping. I stopped cleaning other folks boats because they did not maintain their paint and some were a nightmare.
#6 Putting a lanyard on your 'tools' may be a good idea, BUT you have to weigh that against the chance of entanglement and just plain hassle.
#7 (Should be number 2) This is a real dive. Wear the right gear and monitor your air supply!!! (see #1)
#8 Some of the stuff on your boat may be very abrasive/nasty. Definitely wear gloves and consider protecting other skin.
#9 (if you got this far) Consider the other folks advice about getting someone else to do it!

BTW, now I have a boat I trailer.

Hi all,

I am cleaning the hull of my boat using a brush and a scraper. It is in the water and I am not going to pay someone to do it, I want to experience the pain. So, if anyone does this kind of stuff, do you start at the water line with a green scrubbie, then work your way down?

Again, thanks for any help,

August

 

[scubaskipper]

If you can take the boat out of the water it's allot easier. The biggest thing is not to let it dry. Much of the stuff will be like iron to get off, if you let it dry. We had good bottom coating so a pressure washer took off 99% and a paint scraper took off the rest. We had 6 rental boats we had to keep up on. Watch you don't peel off the bottom coating with the pressure washer. Good luck, it really is easier to have someone else do it.

 

[Navy]

If your boat does not have paint on the bottom use a scraper to remove the hard growth, and grass. After that a stainless steel sponge or coarse pads to remove what is left.

If your boat has paint on the bottom use a scraper to remove the hard growth, and grass. After that start with a green pad, and try not to take off the paint.