Removing Barnacles Leftovers

[zboss]

Even though we lift our dinghy out every night we still end up with a lot of barnacles on the outboard engine.

After scraping them off we end up with hard stuff left over... does anyone know how to get that junk off? Is there a chemical that breaks up the shell leftovers?

[sparrowhawk1]

Muriatic acid also known as hydrochloric acid dissolves calcium. it's also handy for removing rust stains. It doesn't seem to hurt gel coat. not sure how it will affect the paint on the outboard so use at your own risk.

[jcapo]

MaryKate's On & Off works well and may be a bit easier on aluminum. Its phosphoric acid IIRC.

[Reefmagnet]

Be aware that HCl acid will eat aluminium but is very effective. For a less aggressive solution, try a mixture of vinegar and flour to form a paste, spread thickly over the barnies and with a garbage bag over the lot to prevent drying. Give it half an hour or so and wash/scrub off. Repeat as neccesary.

[Arthur Garfield]

Reefmagnet ,
I like that recipe.
Sounds quite practical and enviro!
Thanks

[zboss]

In the future... Can the bottom just be spray painted with that zinc paint?

[Cheechako]

My experience with all bottom treatments is they don't stop the growth, they just kill it after it attaches.

[sparrowhawk1]

Originally Posted by zboss

In the future... Can the bottom just be spray painted with that zinc paint?

Yep. it won't last long on your prop but will protect your lower unit although its pretty expensive. Edit: I was thinking of tin antifouling spray on paint

[a64pilot]

Your dinghy is out of the water every night and yet it has barnacles? Is this common?

[zboss]

Originally Posted by a64pilot

Your dinghy is out of the water every night and yet it has barnacles? Is this common?

EVERY night. Its very common here. Most of the cruisers here go up to a place called bird island to clean their bottoms at low tide.

Can I tell you we are REALLY looking forward to the bahamas this year?!

I asked about the zinc paint because I used that on our big boat prop about a year ago and its been in the water ever since and it going strong.

I sanded and treated the prop with a little paint etcher before application, to get microgrip of the paint to the prop. My divers keep telling me how clean our prop is.