Phone:
(701)814-6992
Physical address:
6296 Donnelly Plaza
Ratkeville, Bahamas.
Pontoon Tube Care & Inspection
Pontoon tubes spend their lives doing the hard work underneath the boat.
They provide flotation, support the deck and everything on it, absorb contact with docks and trailers, and deal with submerged objects, vegetation, sand, mud and whatever else the water puts in their way.
Fortunately, aluminum pontoon tubes are relatively simple structures.
That also makes visual inspection one of the best maintenance tools a pontoon owner has.
Regular pontoon tube inspection can help identify dents, damaged welds, corrosion, pitting, leaks and other developing conditions before they become larger problems.
The goal isn’t to panic over every scratch or dent.
It’s to learn what your pontoon tubes normally look like—and recognize when something changes.
Pontoon Tube Inspection Menu
Quick Inspection | Dents & Damage | Welds & Seams | Corrosion & Pitting | Leaks & Water Intrusion | Brackets & Attachments | Cleaning | Repairs | When to Get Help
Quick Pontoon Tube Inspection
You don’t need to perform an exhaustive inspection every time the boat leaves the driveway.
A quick walk-around can still reveal quite a bit.
Look along both sides of each tube and check:
- Nose cones
- Tube sides
- Bottoms where visible
- Rear sections
- Welded seams
- Lifting strakes where equipped
- Brackets and attachment points
- Previous repairs
- Areas near trailer bunks and guides
- Areas that regularly contact docks
Look for anything that appears different from the last time you inspected the boat.
That could include:
- New dents
- Deep scratches or gouges
- Cracks
- Damaged welds
- Corrosion
- Pitting
- Discoloration
- Loose components
- Evidence of impact
- Signs of leaking
A flashlight can help when inspecting underneath the boat and around brackets.
Taking occasional photographs of the tubes can also give you something to compare against later.
Dents & Impact Damage
Pontoon tubes get dented.
Dock contact, trailer loading, submerged objects and previous owners all leave evidence behind.
A small cosmetic dent isn’t automatically a structural problem.
What deserves more attention is the location, depth and shape of the damage.
Pay closer attention to dents that:
- Are deep or sharply creased
- Distort a welded seam
- Affect a bracket or attachment point
- Occur near the nose cone
- Damage a lifting strake
- Appear to have stretched or torn the aluminum
- Are accompanied by a crack
- Continue changing
- Follow a significant impact
Look Beyond the Dent
If you know the boat recently struck something, don’t stop your inspection at the obvious damage.
Look around it.
An impact strong enough to significantly deform the tube may also affect nearby welds, brackets or structural connections.
Inspect the opposite and surrounding areas where practical.
Scratches and Gouges
Surface scratches are common.
Deep gouges deserve more attention, particularly if they significantly reduce material thickness or expose an area where corrosion can develop.
If you’re unsure how significant damage is, document it with photographs and have it evaluated before attempting a cosmetic repair.
A shiny patch of paint or polish doesn’t restore damaged aluminum.
Welds & Seams
Pontoon tubes depend heavily on welded connections.
Depending on the tube design, welds may be found around:
- Nose cones
- End caps
- Sections of the tube
- Lifting strakes
- Mounting brackets
- Structural attachments
- Transom or motor-pod components
- Previous repairs
What to Look For
Inspect accessible welds for:
- Visible cracks
- Separation
- Damage following an impact
- Corrosion around the weld
- Discoloration or staining
- Previous repairs that appear to be changing
- Evidence of water escaping from an area
You aren’t trying to judge the beauty of the weld.
You’re looking for evidence that something has changed or failed.
Don’t Ignore the Area Next to the Weld
A failure doesn’t always occur directly through the weld bead.
The aluminum immediately adjacent to a weld can also deserve attention.
If you see a crack, deformation or suspicious condition near a structural weld, don’t assume it’s harmless simply because the weld itself still appears intact.
Corrosion & Pitting
Aluminum resists corrosion well because it naturally develops a protective oxide layer.
But aluminum is not corrosion-proof.
Pontoon tubes can develop corrosion under the right conditions, especially when moisture, contaminants or dissimilar metals are involved.
Watch for:
- White or chalky deposits
- Rough areas
- Small pits in the aluminum
- Flaking or deteriorated material
- Corrosion around fasteners
- Corrosion around brackets
- Deterioration underneath trapped debris
- Unusual localized discoloration
Dissimilar Metals Matter
When certain different metals remain in electrical contact in the presence of an electrolyte such as water, galvanic corrosion can occur.
That’s one reason hardware and accessories shouldn’t simply be attached to an aluminum pontoon without considering material compatibility and proper installation.
Pay particular attention around:
- Aftermarket accessories
- Fasteners
- Brackets
- Transducers
- Wiring attachments
- Grounding/bonding components where applicable
- Previous modifications
A random screw installed years ago can create a surprisingly interesting science experiment.
Unfortunately, the pontoon tube gets to participate.
Saltwater
Saltwater increases the importance of corrosion inspection and freshwater rinsing.
A pontoon regularly operated in saltwater deserves closer attention around welds, brackets, fasteners, motor-mounting components and other areas where different metals or trapped contaminants may be present.
Don’t Sand Everything Shiny
Aggressively grinding or sanding corrosion isn’t automatically the correct repair.
You may remove additional material without knowing how much sound aluminum remains.
Significant pitting or material loss should be evaluated before attempting to make it look better.
Pontoon Tube Leaks & Water Intrusion
Water inside a pontoon tube deserves investigation.
Depending on the tube’s design, it may contain separate chambers or internal bulkheads. Construction varies by manufacturer and model.
A small amount of condensation may be possible in some situations, but unexplained or recurring water shouldn’t simply be accepted as normal.
Possible Signs of Water Inside a Pontoon
Watch for:
- One side of the boat sitting unusually low
- A change in how the boat floats
- Unexplained performance loss
- Increased difficulty getting underway
- Unusual handling
- Water sounds inside a tube
- Water draining from somewhere unexpected
- Recurring water after previous draining
- Visible tube damage
None of those symptoms alone proves that a tube is leaking.
They tell you it’s worth investigating.
Drain Plugs
Some pontoon designs may have manufacturer-provided plugs or service points.
Others may not.
Don’t drill a hole into a pontoon tube simply because you suspect water is inside.
Determine how that particular tube was designed to be serviced.
Finding a Leak
Leak diagnosis may involve pressure testing by someone familiar with aluminum pontoon construction.
A pontoon tube is not something to treat like a high-pressure air tank.
Improper pressurization can damage the tube or create a hazardous condition.
If pressure testing is required, follow the manufacturer’s procedure or have the tube evaluated by a qualified marine or aluminum repair professional.
Fix the Cause, Not Just the Water
Removing water doesn’t repair the leak.
If water repeatedly enters a tube, determine how it’s getting there.
Otherwise you’ve solved the symptom and kept the problem.
Brackets, Attachments & Structural Connections
The tubes don’t work independently from the rest of the boat.
They have to support the structure above them.
Inspect accessible:
- Tube mounting brackets
- Crossmember connections
- Welded attachment points
- Fasteners
- Lifting strakes
- Splash components
- Motor-pod connections
- Transom-related structures
Look for:
- Cracked welds
- Loose hardware
- Distorted brackets
- Corrosion
- Movement
- Elongated fastener holes
- Impact damage
- Evidence of components rubbing against the tube
Trailer Contact Areas
Pay special attention to where the pontoon interacts with the trailer.
Improperly positioned or damaged bunks, brackets and guides can repeatedly contact the same area of a tube.
One bad loading event can cause damage.
A poorly adjusted trailer can cause damage a little at a time.
Inspect the trailer along with the boat whenever unusual wear appears on the tubes.
Future Resource: Pontoon Trailer Care & Setup →
Cleaning Pontoon Tubes
Cleaning isn’t only about appearance.
A clean tube is easier to inspect.
Mud, algae, mineral deposits and other buildup can hide the aluminum underneath.
Routine Cleaning
After use:
- Remove vegetation and debris
- Rinse contaminants away
- Rinse thoroughly after saltwater exposure
- Clean accumulated scum as necessary
- Pay attention around brackets and hard-to-reach areas
- Allow appropriate areas to dry
Use cleaning products that are compatible with aluminum and with any coating or finish applied to the tubes.
Bare Aluminum Changes Appearance
Uncoated aluminum naturally oxidizes and changes appearance.
That doesn’t necessarily mean the tube is failing.
There’s a difference between normal surface oxidation and significant corrosion or pitting.
The objective isn’t necessarily to make every pontoon tube look freshly polished.
It’s to keep it clean enough to inspect and prevent damaging contaminants from remaining where they shouldn’t.
Be Careful With Aggressive Cleaners
Strong acids, highly alkaline products, abrasive compounds and incompatible chemicals can damage aluminum or surrounding materials.
Follow product and boat-manufacturer recommendations.
If the label doesn’t clearly indicate that a product is appropriate for the material you’re cleaning, don’t let your pontoon be the test sample.
Future Resource: How to Clean a Pontoon Boat →
Previous Pontoon Tube Repairs
Older pontoons may already have repaired tubes.
A previous repair isn’t automatically a reason to reject or distrust a boat.
A properly completed repair can remain serviceable for years.
But repaired areas deserve periodic inspection.
Look for:
- New cracks
- Corrosion
- Separation
- Distortion
- New leaking
- Changes around the repair
- Repeated repair in the same area
Also consider why the repair was originally necessary.
If a tube was repaired after trailer damage but the trailer was never corrected, the source of the problem may still exist.
The same applies to corrosion, structural movement and impact damage.
Good repair work addresses the damaged material.
Good maintenance also addresses what caused the damage.
↑ Back to Pontoon Tube Inspection Menu
Repairs & Modifications
Pontoon tube repair is different from repairing many non-structural parts of the boat.
These tubes provide flotation and are part of the structure supporting the boat.
Welding thin marine aluminum requires appropriate equipment, materials and skill.
Avoid Improvised Structural Repairs
Be cautious with:
- Random screws driven into tubes
- Unverified sealants used as permanent structural repairs
- Patches applied without understanding the damage underneath
- Welding by someone unfamiliar with marine aluminum
- Drilling holes without understanding the tube’s internal construction
- Modifications that create new corrosion points
Temporary measures may sometimes be useful to get a boat safely out of a situation.
That doesn’t make them permanent repairs.
Before Modifying a Tube
Think carefully before attaching:
- Transducers
- Brackets
- Lights
- Wiring hardware
- Accessories
- Steps
- Other equipment
Know how the accessory will be attached, whether the materials are compatible and whether the installation could create a leak or corrosion problem.
The easiest hole in a pontoon tube to repair is the one you never drilled.
When to Get Professional Help
Some conditions are worth having evaluated rather than guessing.
Consider professional inspection or repair when you find:
- A visible crack
- A leaking tube
- Recurring water intrusion
- Significant pitting
- Severe corrosion
- Deep or sharply creased damage
- Damage involving structural brackets
- Cracked structural welds
- Damage near the motor pod or transom
- Major impact damage
- A previous repair that appears to be failing
- A tube that appears to be losing material
- A boat that suddenly sits differently in the water
Also get help when you simply can’t determine the significance of what you’re seeing.
There’s nothing wrong with knowing where DIY inspection ends.
Finding the problem yourself doesn’t mean you have to repair it yourself.
Make Tube Inspection Part of the Routine
Pontoon tube inspection doesn’t need to become a complicated maintenance ritual.
Most of it comes down to paying attention.
Know what the tubes normally look like.
Walk around the boat.
Look underneath when you have the opportunity.
Inspect after an impact.
Watch corrosion.
Check welds and attachment points.
Pay attention when the boat’s performance or attitude in the water changes.
And don’t hide a problem simply because it’s ugly.
The tubes don’t have to look perfect.
They need to continue doing their job.
Pontoon Boat Owner’s Guide →
Tin Can Boat Works
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