How to Clean a Pontoon Boat

Most boat cleaning advice assumes fiberglass. A pontoon is not fiberglass, and that is why generic guidance produces mediocre results on one.

You actually have three different jobs that happen to share a trailer: bare aluminum tubes below the waterline, an unusually large amount of vinyl furniture above it, and flooring that sits flat and holds water.

Each wants something different. Doing all three with the same bottle is the mistake.

The tubes

This is the part that is genuinely unlike other boats, and we should be straight with you: Velari does not make a product for this. Our chemistry is built for gelcoat, vinyl, glass and trim. Bare aluminum is its own category.

Here is what you need to know anyway.

Aluminum tubes oxidise, and below the waterline they pick up a brown or black band from mineral staining, algae and whatever the lake is carrying. Ordinary boat soap will not touch it, because the staining is chemical rather than dirt sitting on the surface.

The standard answer is an acid-based pontoon cleaner, usually hydrofluoric or phosphoric acid. It works, and it works fast. It also deserves respect:

• Gloves and eye protection, every time, no exceptions. Hydrofluoric acid in particular causes injuries that do not hurt until hours later.
• Work in sections and never let it dry on the metal.
• Rinse heavily and keep the runoff away from your lawn, the trailer, and anything painted or anodised.
• Keep it entirely off the vinyl, the fencing and the deck.
• Check your marina's rules. Many prohibit acid cleaning in the water.

If the staining is light, a dedicated aluminum brightener without hydrofluoric acid does the job with far less risk. Try that first.

The furniture, which is most of the boat

A pontoon carries more vinyl per foot than almost anything else on the water. Wraparound lounges, facing benches, helm chair, sun pad. On a 22-foot pontoon that is a serious amount of surface, and it is the part guests actually touch.

It is also the part that fails first, and the reason is always the same: sunscreen and body oil. Pontoons are social boats. More people, more sunscreen, more hours sitting in the sun. That combination soaks into marine vinyl and, left alone, strips the plasticizers that keep it flexible.

Use a marine interior cleaner rather than anything from the household shelf. Bleach, ammonia, alcohol and melamine erasers all attack vinyl, and on a pontoon you have a lot of vinyl to lose. Cabin Revive lifts the oils and leaves a protectant behind, which matters when the furniture is uncovered all summer.

Work the seams separately. Pontoon furniture has a lot of them, and seams are where mildew starts because they hold water and never fully dry. A soft bristle brush along the length of each seam does what a flat wipe cannot. Soft matters, because stiff bristles fray stitching and a split seam means reupholstery.

We wrote up the detail on both of those: cleaning vinyl without cracking it and getting mildew out of seams.

The deck

Pontoons are flat, which means water sits rather than runs off. Whatever your flooring is, that is the problem you are managing.

Marine carpet holds water against the deck and is a mildew farm if it never dries. Pull removable sections, clean both sides, and dry them off the boat.

Woven vinyl flooring is easier but the texture traps grit. Rinse before you scrub, or you are grinding sand into it.

Either way, get water off the deck rather than letting it evaporate in place, and never close the cover over a damp floor.

Fencing, rails and the rest

Powder-coated or anodised aluminum fencing takes ordinary marine soap and a wash mitt. It does not need, and should not get, the acid you used on the tubes. Overspray is the usual way fencing gets damaged.

Bimini frames, grab rails and stainless hardware all come up with the same soap and a rinse.

A working order

1. Strip the boat. Cushions, carpet, anything loose.
2. Rinse everything to get grit off before anything abrasive touches a surface.
3. Wash the topside, fencing, rails and deck with marine soap.
4. Clean the vinyl, surfaces first, then work every seam with a soft brush.
5. Glass and any clear canvas, with an ammonia-free cleaner.
6. Tubes last, with the acid cleaner, after everything above is rinsed and the boat is on the trailer.
7. Final rinse and dry. Leave it open until the deck is genuinely dry.

Tubes go last on purpose. You do not want acid overspray landing on furniture you just finished.

The short version

Three jobs, three approaches. Tubes need acid and real caution. Furniture needs marine-safe chemistry and attention to the seams, because sunscreen is what kills pontoon vinyl. Flooring needs to actually dry.

For everything above the waterline, the Complete Boat Care System covers it in one go: marine soap, interior cleaner, glass cleaner, ceramic spray, wash mitt, microfiber towels and the seam brush. $149.95.

For the tubes, buy a dedicated aluminum cleaner and wear the gloves.