Hull fouling

[ribber]

Ok, boat power washed with industrial hot water jet wash and 9 hours laid on my back, with scouring pad and scraper, under the trailer and boat......

I can't believe the difficulty of getting the last oily slime of the bottom. I'm moored in the Itchen and I guess, not the cleanest water in the world. But this oily residue was horrific to remove.

Unfortunately I had left the boat to dry out more this time and the result was this hard crust that literally had to be scraped off, perhaps I should do this straight out from the water.

Final brush down with oxalic acid and the hull has come up bright white, removing the yellowing as if by magic.

I'm one for running up the beach and not overly worrying about scratches and chips in gel coat, always repairable, but with my added scraping, has over the last 15 years, created a good key for green sludge.

Still no more, as next year, sitting on a Tetradock....

[Limecc]

I wasn't aware of the effectiveness of oxalic acid, I think I'm going to get some. I would normally use full strength caustic TFR on a job like this, how do you think this would have worked in comparison?

[ribber]

Hi limecc, really no easy way to get the slime off apart from scrubbing.... The oxalic really just gets rid of the yellowing. Tfr is probably better to attack the slime, but when applied and lying underneath the resulting drips running down your arms and face make for selling the boat a clever choice...�� I just don't think there is a magic formula....

[Limecc]

At Lymington I saw Scorpion guys taking them out and using a pressure washer on the hull. Seemed easy enough.

I used TFR on algae encrusted boat covers, caravans, patios etc and it works like magic.

Barnacles could be dissolved? Probably Oxalic acid can be used for that? I read that growth from a saltwater mooring drops off when moored in freshwater, not really applicable for rib owners though.

[paulbrown22]

Originally Posted by ribber

Unfortunately I had left the boat to dry out more this time...

I find that makes a huge difference on our sailing yacht, which lives afloat, and comes out at some point over winter for maintenance. If we immediately pressure wash it on haul out and spend some time removing any slime, growth, etc., it's far, far easier doing it then than if it sits ashore for a month, and we try to do it later on. Letting it all dry out really seems to make it stick on even more!

When I pulled my Ribtec out back in Aug after 3-4 months afloat in Poole (with one very brief interim pull out and pressure wash with a fairly knackered pressure washer...), I did the same, spent at least an hour with the pressure washer (which admittedly is on it's last legs), and a tiny bit of scraping in a few places for barnacles, and it was all good.

[GuyC]

Originally Posted by paulbrown22

When I pulled my Ribtec out back in Aug after 3-4 months afloat in Poole (with one very brief interim pull out and pressure wash with a fairly knackered pressure washer...), I did the same, spent at least an hour with the pressure washer (which admittedly is on it's last legs), and a tiny bit of scraping in a few places for barnacles, and it was all good.

Is that with or without antifoul?

[paulbrown22]

Without any recent antifoul, although I've never tried to completely remove what the previous owner had applied back in 2011/2012 before I bought it, not that I imagine that does anything useful anymore!

Our previous Avon Adventure 620 we had from new, never anti fouled, and kept in the marina year round. Similarly, it would get typically two pressure washes and scrub/scrapes per year immediately on lift out, and then go straight back in, and we never had any growth there that didn't fairly easily come off.

[ribber]

Perhaps it's the River Itchen then, the general flotsam floating by and what seems to be oily coating on the hull is not good. It does make you wonder if any monitoring of the river and Southampton Water generally are as strict as they could be. Another topic I guess.

[GuyC]

Originally Posted by paulbrown22

Without any recent antifoul, although I've never tried to completely remove what the previous owner had applied back in 2011/2012 before I bought it, not that I imagine that does anything useful anymore!

Thanks for that - my hull is in the same state.