Barnacles on RIB

[CarlF]

I normally store the RIB out of the water but this year with COVID it sat in the water for a couple of months. Pulled it out and found an amazing amount of growth.

I have a small power washer that took off most of it but there still remains a bumpy brown stain. None of my light duty cleaners touch it.

Can I use On-and-Off that I use on the fiberglass to take off ICW stains? It's hydrochloric acid and phosphoric acid. Will this hurt the hypalon or the PVC of the Walker Bay hull?

If that's not a good idea - other suggestions?

[robert sailor]

Hypalon can deal with both of these acids but you should keep them to no more than 30% so check the label for strength. On off can be cut with water, we do not need to use it full strength to clean up the waterline, we use about 1/3 on off to 2/3 water.

[atoll]

oxalic acid (crystals) works great for stains and calcium growth from barnacles on both the glass hull and pvc tubes.
it also cleaned up the tubes on top where they had become discolored from the sun,both my dinkies look like new now......apart from all the patches

[chris in SG]

Noted that the OP does not intend to make a habit of leaving the inflatable afloat, but I just wanted to offer my experience, many years ago, of living onboard on a swing mooring and working ashore. After a couple of years of dealing with barnacles, I tried antifouling the (Hypalon) dinghy. It was successful. The paint was regular yacht hull antifouling and had sufficient flexibility to stay intact without cracking unless the dinghy was left inverted in the sun for a while.