How to Repair and Maintain Your Hydro Foil

Whether you ride too shallow while wing foiling or your board gets blown over in the parking lot, damage to your hydro foil is almost inevitable over time. In this guide, we’ll walk you through common hydro foil damage, what you can repair yourself, and when to seek professional help.

Before You Start Any Hydro Foil Repair

A few things to keep in mind before reaching for tools:

It’s easier to remove material than to add it back. Go slow when sanding.
Avoid power tools. These can cause serious damage to carbon or aluminum foil components if used improperly.

When to Call a Pro

If you’re unsure or uncomfortable with any repair work, it’s best to seek professional hydro foil repair service. Poor repairs can impact performance or cause further damage. Your local surf or wing foil shop may offer repairs or know a someone who handles carbon foil repair – bike frame specialists are often a great option too.

Reach out to foil store in your area

Dealing with Common Hydro Foil Damage

Light Scratches and White Marks

Scratches are among the most common issues and luckily, they’re also the easiest to deal with. Most of the time, these are purely cosmetic and don’t affect performance.

What you need – 1000 and 1800 grit wet paper.

Work by hand, using plenty of water, and sand lightly across the surface working evenly across the foil. It’s best to start with the 1000 grit, then follow up with 1800 to smooth everything out. When sanding near trailing edges, be extra gentle. And if you start seeing carbon in the sanding paper (water tinted black) stop – you’re going too deep. Make sure to dry the foil completely to see your progress/finished results.

Deep Scratches and Grooves

Deeper scratches or grooves that you can feel with your fingernail will need filling before sanding.

What you will need: 1000 and 1800 grit wet paper and a sanding block and you’ll also need a filler.

Two good filler options are a two-part automotive body filler or a UV-cured epoxy like Solarez. The two-part filler is easy to sand and forgiving to work with, but generally cures quickly and requires more prep work.

Solarez is great for quick fixes – it cures in sunlight – but it’s hard to sand, so be very careful not to apply too much, and be sure to remove any excess before allowing it to cure.

Before applying filler, tape off the area around the damage to avoid spreading the repair too wide. Clean the area and do a light sanding to roughen the area which will allow filler to bond better. Use a spatula or even an old credit card to press the filler into the groove, then scrape away any excess before it hardens. Once cured, sand it flush with a sanding block starting with 1000 grit, then use 1800 grit to finish it off.

Whistling Foils

A whistling hydrofoil can drive you crazy. While there are many possible causes, it usually comes down to the trailing edge of your stabilizer, front wing, or mast being too sharp or uneven.

What you will need: your high-grit wet sandpaper (1000 and 1800) and a sanding block.

Start by figuring out which part is making the noise. The stabilizer is often the main culprit, followed by the front wing, and lastly the mast.

Once you’ve identified the source, use wet sandpaper and a sanding block to gently sand the trailing edge at about a 30-degree angle on the high-pressure side.

For the front wing, that’s the top side; for the stabilizer, it’s the underside.

If you’re working on a mast, sand both sides at a 30-degree angle.

After you’ve sanded the trailing edge, it can be incredibly sharp, you can lightly blunt it with the sanding block at a flat 90-degree angle.

Go slowly and remove as little material as possible—small changes can make a big difference in airflow and sound.

Cracks and Damaged Carbon

Cracks are a bigger deal – but fortunately, they’re also the least common type of damage. Unlike surface scratches, cracks usually point to structural issues and shouldn’t be ignored.

The good news is that cracks in stabilizers and front wings can often be repaired by professionals without a noticeable drop in performance. Cracks in masts, however, are much more serious. Since the mast takes the most load, riding with a cracked mast puts your entire hydro foil setup at risk. In that case, replacing the mast is the safest choice.

If your foil has fallen over and the tip of your front wing or stabilizer is damaged, the repair can be trickier. But with the right tools and experience, a skilled carbon repair specialist should be able to rebuild the wingtips and get them close to their original shape and function.

If you’re unsure what you’re doing, it’s best not to attempt wingtip repairs yourself—small mistakes can throw off the balance and reduce the performance of your hydro foil.

Threaded Inserts and Screws

Screws and threads can be tricky. Most of the time, it’s better not to attempt a thread repair yourself unless you really know what you’re doing.

But prevention is simple. If a screw looks worn or bent, replace it before it gets stuck. And make a habit of cleaning your threads – rinse them well after each session to keep sand and salt from building up.

If you do strip a screw or damage a thread, take the part to a professional. In carbon parts, a damaged thread often means the whole piece needs replacing. In aluminum fuselages, however, there’s a chance it can be saved with a helicoil insert – just make sure it’s stainless steel, otherwise it’ll rust quickly.

Why Repairs and Maintenance Matter

Keeping your gear in good condition isn’t just about appearances. Well-maintained hydro foils perform better, ride quieter, and last longer. Smooth surfaces help reduce turbulence and prevent ventilation, especially when wing foiling in gusty or choppy conditions.

Regular maintenance also saves you money over time. Catching small issues before they turn into big ones keeps you on the water and out of the garage doing repairs.

Interested in anything wing or foil?

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