Killing marine growth before pressure washing?
 

Just pulled my boat after my first year keeping the boat in a slip. Getting the boat ready for winter and also need to get the boat cleaned up. I live next to a river with a storm drain at the bottom of my driveway so I have some concerns.

When I went to the marina to pull the boat out, I noticed one of the workers spraying the bottom of one of the boats he was going to power wash. He was wearing a respirator as the sprayer was creating a pretty big cloud of overspray. I had to pause and let it clear before passing by. Should have asked what it was.

Found a bunch of hull and bottom cleaners but have read not to use these with anti-foul paints.

Anyone have some input and advice on how to kill the growth prior to power washing the bottom?

I don't - I just pressure wash it off - never been a problem. The only time I've used one of the proprietary bottom cleaners, was on bare gel to remove weed when I didn't have access to a water supply - it is nasty stuff and you need to read the instructions if you do use it, but I would try going straight to the pressure washing first and see how you get on.

Hit it when it first comes out and before it dries. Booyah is fantastic stuff and isn't harsh at all but I would still question using it on an anti-foul.

If your boat has bottom paint on it what kind of marine growth do you have on the bottomm of your boat? It almost sounds like your bottom paint is not doing it's job. Are you using the right paint for your area?
I never have to use any chemicals to clean the bottom of my boat, just pressure wash it.

Sounds like you are in brackish water getting the brown staining. Most likely muriatic acid was what you saw being used.

A lot of the boats coming out of the water at the marina have a lot more growth than mine. I used some pretty expensive Pettit this spring. I've just a light bit on the bottom but more on the drive. We used the boat quite a bit and the bottom paint did its job.

I know a light pressure wash will take what little growth I have off. Even on the drive I can rub it off by hand. Issue is not wanting to contaminate the fresh water across from my house.

I am at the top of Point Judith Pond where the river feeds in so yes. For the part above the water line, I can use a gel if washing doesn't take care of the staining. That part I figured out. I trailered the boat for two years before this year so none of this was a problem before. Just one more thing to figure out.

Not contaminate the fresh water with chemicals or the growth? If you are worried about chemicals Booyah is biodegradable. My boat is on a lift but I sometimes leave it in for a week. Their hull cleaner gets the skim line with no effort and I can use it right in my slip.

https://www.booyahclean.com/collecti...t-hull-cleaner

I still think it's a bad idea to put chemicals on your anti foul unless you plan to paint it again in the spring.

What is the best way to get rid of that brown stain? Will pressure washing alone do it or should something else be used?

I do not want to contaminate the water with the growth which I feel would do more environmental damage than just about any chemical usage that made it way to the river. I am about 600ft from the river but the storm drain is at the bottom of the driveway. So as the title might suggest, I'd like to kill the growth and also do as little damage overall to both the bottom paint and environment.

How about using a self service car wash in town away from the river?

Sno Bol toilet cleaner works really well.

Jim

Great idea but I'd have to find one tall enough to fit the boat. It's a pretty tall pilot house. I'll stop by one that is nearby with a tape measure when I run some errands later.

Agree, that's what they use around here.

Seems I've come up empty with looking for a general purpose biocide for this. Also boat is too tall for any of the local car washes.

Plan B.
Move the boat to the back portion of the yard and use a couple extra lengths of hose on the power washer. This way what ever washes off is not likely to run off and instead gets absorbed into the ground. Got a spot that is mostly gravel along the back of the lot where the lawn ends. Going to leave tracks in the lawn though where it is soft.

It is much easier to clean it when it is still fresh and wet. Muriatic Acid is just for the waterline. The rest just gets blown off.

Another vote for booyah. I’ve been using it for a few years. Works great. Also doesn’t hurt when it gets on my skin.

Bleach and water. Let it sit a few hours, will kill all the marine growth. Hit it with pressure washer.