How to Clean, Brighten and Protect Aluminum Pontoon Tubes

Pull the boat out on its trailer or have the marina lift it. Park on a level spot away from storm drains if you can. If you need to raise the boat to reach the tube bottoms, follow pontoon-lifting-jacking and use solid stands, never just a jack. Cover carpet, decals and the trailer if you'll use anything stronger than soap.

Growth and scum come off far more easily before they dry. Rinse each tube top to bottom, including the weld seams and the bottoms, where Discover Boating notes algae and scum build up most. A pressure washer on a moderate setting helps on bare tubes; keep the nozzle moving and well back from decals, seams and the motor pod.

Use a boat soap and a soft brush. Boating Magazine quotes builders saying a rinse goes a long way and mild soap does the rest for routine washdowns; rinse coastal boats more often to remove salt. Rinse thoroughly. For many boats, especially painted or coated tubes, this is all you should do. Avalon recommends purpose-made aluminum cleaners for aluminum parts and warns against household cleaners, which can react with aluminum.

Before you brighten or polish anything, walk around each tube and look for:

• Pitting, white powdery spots or bubbling paint (corrosion; see aluminum-hull-corrosion)
• Cracked welds, dents, loose brackets and missing or worn anodes
• Weeping or rust-colored stains at seams and drain plugs (see pontoon-tube-leak)
• Stainless fasteners touching bare aluminum without isolation

Mark anything you find with tape and photograph it. Cleaning can hide or worsen corrosion if you scrub over it.

For waterline stains and light oxidation, start with a non-acid pontoon or aluminum cleaner made for marine use. Test it on a small spot on the inside of a tube first. Apply, let it work for the time on the label without letting it dry, brush gently and rinse thoroughly. Repeat rather than scrubbing hard.

Only consider an acid brightener for bare aluminum tubes with stains or oxidation that mild cleaners won't touch. Before buying:

• Read the SDS (section 2 for hazards, section 3 for ingredients). Look for hydrofluoric acid (also listed as hydrogen fluoride, CAS 7664-39-3). If you can, choose a product without it.
• Read the label's surface warnings: many say not for painted, anodized or polished aluminum.
• Check your builder's care instructions; some warn against acids entirely.
• Avoid muriatic acid and other hardware-store acids. Discover Boating warns harsh acids like muriatic can streak and weaken aluminum.

If you have any doubt, hire a pontoon detailer who does acid brightening routinely, on a proper wash pad.

• Wear splash goggles and a face shield, chemical-resistant gloves and the clothing the SDS lists. Long sleeves, long pants, rubber boots.
• Work outdoors, in the shade, with the wind at your back, on a cool tube. Hot metal makes acid work too fast and streak.
• Wet the tube with water first. Then apply the brightener with a plastic pump sprayer, working one small section at a time, bottom to top so it doesn't run down over dry metal in streaks.
• Don't let it dry. Brush lightly if the label says to, then rinse thoroughly within the time on the label, top to bottom, with lots of water.
• Keep the spray off decals, carpet, vinyl, the outboard, stainless steel, the trailer and galvanized parts; rinse those immediately if hit.
• Keep a hose running nearby the whole time so you can rinse skin or eyes instantly.

Acid trapped in seams, brackets and the trailer bunks keeps working. Rinse every seam, bracket and the trailer twice. Don't let the runoff go into the lake, a storm drain or your garden. Follow the label for neutralizing and disposal, and take leftover product to your local household hazardous waste program.

For a shine on bare tubes, use a marine aluminum polish on a clean, dry surface, one small section at a time, with a microfiber cloth or an orbital polisher. Polish until the black residue stops coming off, then buff clean. Never use steel wool or carbon-steel wire brushes: steel particles left in the aluminum cause rust spots and corrosion. Don't polish painted or anodized tubes with metal polish; use the product the builder recommends.

Finish with a marine aluminum sealant or protectant. Discover Boating says a sealant helps repel water spots and grime, slows oxidation and makes later cleaning easier. Avalon recommends waxing the aluminum tubes and side panels every three to six months during the season. Follow the product's coverage and cure time before relaunching.

• Rinse after every outing, more often in salt or brackish water (see pontoon-saltwater-use).
• Wipe off scum lines with a damp cloth or mild cleaner before they set.
• Store on a lift or trailer out of the water when you can (see boat-lift-care).
• Clean the tubes before winter storage (see winterize-pontoon).

Note the cleaner, brightener, polish and sealant brands and the date in your BoatMend boat profile, plus any spots you marked in step 4. Next season you'll know what worked and whether any corrosion is spreading.