Refitting an aluminium mast
Cleaning, corrosion repair and painting of an aluminium mast, plus inspection of fittings and tracks.
An aluminium mast is a structural member whose condition decides the safety of the whole rig. The refit is best done with the mast unstepped and laid on trestles, which gives access to the whole surface and to the fittings. Start the inspection by looking for pitting corrosion, cracks around rivets and holes and signs of galvanic corrosion where aluminium meets steel. Photographing the starting condition makes it easier to plan the repairs.
The mast's worst enemy is galvanic corrosion, which forms where stainless fittings meet aluminium without insulation. White, powdery aluminium oxide and paint lifting under the fittings are the warning sign. Remove the fittings, clean out the seats and, on refitting, use an insulating paste (Duralac or Tef-Gel) and the right fasteners. That is the basic rule for preventing further electrochemical corrosion.
Prepare the surface mechanically: remove old, flaking paint and the oxidised layer, then degrease the aluminium and key it lightly. Freshly cleaned aluminium quickly forms an oxide layer, so apply the primer without delay. A dedicated primer for aluminium (etch primer or epoxy primer with an activator) is crucial, because it decides the adhesion of the whole paint system. Without the right primer, even the best paint will soon come off.
Smooth out corrosion pits and fill deeper losses with an epoxy filler intended for metal. Once dry and sanded, apply the topcoat system — the most durable are two-pack polyurethane paints, resistant to UV and abrasion. Paint in thin coats, ideally sprayed or with a foam roller, allowing the flash-off time between coats. Work at the temperature the maker recommends and with no moisture on the surface.
While you are at it, carry out a full inspection of the hardware: blocks, the mainsail luff track, spreaders, shroud and stay attachments, lights and the wiring inside the mast. Replace corroding screws with new ones in A4 stainless, fitting them with insulating paste. Clean and lubricate the track and sheaves with a PTFE-based product, avoiding greases that attract dirt. It is worth running the wiring inside a conduit so it does not knock against the mast walls (the rattle at night can be very tiring).
The masthead and its fittings deserve particular attention, because working aloft after launching is difficult and dangerous. Check the swivels, forestay sheaves, the mountings of the wind vane and the antenna, and the masthead light. Secure all threaded joints against undoing (with thread-locking compound or split pins) and round off any sharp edges that sheets and halyards could chafe on. The last step is checking that the drains from inside the mast are clear.
Safety: do sanding and painting in a mask with the right filter, goggles and gloves, in a ventilated place away from sources of ignition — two-pack paints and solvents are toxic and flammable. A mast on trestles must be firmly supported at several points so that it does not bend. When stepping the mast, use a crane or a proven procedure and never work under a suspended load. Dispose of paint waste as the regulations require.
Material prices — products and options
Indicative prices in EUR (incl. VAT), as of July 2026. Products widely available in Europe; prices depend on the shop, the pack size and consumption. The links lead to example shops that ship across the EU. Dollar amounts are converted at 1 EUR = 1.1622 USD (ECB, 7 September 2026) and rounded — treat them as a rough guide, not a price in a US shop. Imperial values in brackets are conversions of the metric figure.
Primer for aluminium (etch primer / epoxy primer)
- International — Primocon
single-pack anti-corrosion/barrier primer, good on aluminium, 750 ml (25 fl oz)€30–40 (≈$35–46) - Hempel — Light Primer
two-pack epoxy primer, suitable for aluminium among others, 750 ml (25 fl oz) / 2.5 l (0.7 US gal)€25–75 (≈$29–87) - International — Interprotect
two-pack epoxy primer for metal, wood and GRP, 750 ml (25 fl oz) / 2.5 l (0.7 US gal)€50–130 (≈$58–151)
Two-pack polyurethane topcoat
- International — Perfection 2K
two-pack polyurethane topcoat, high gloss, 750 ml (25 fl oz)€36–90 (≈$42–105) - International — Perfection Undercoat
two-pack undercoat for Perfection paints, white, 750 ml (25 fl oz)€40–80 (≈$46–93) - Hempel — Brilliant Gloss
single-pack topcoat alternative (easier to apply), 750 ml (25 fl oz)€18–35 (≈$21–41)
Epoxy filler for metal
- International — Watertite
two-pack epoxy filler, non-shrinking, waterproof, 250 ml (8 fl oz) / 500 ml (17 fl oz)€25–45 (≈$29–52) - WEST System — 105 + 403
epoxy resin with microfibres filler for bonding and filling, set€60–120 (≈$70–139)
Insulating paste for aluminium-steel joints
- Duralac — Green
anti-corrosion paste for joining dissimilar metals (steel-aluminium)€28–35 (≈$33–41) - Duralac — classic
chromate paste insulating bolted joints, small tin€12–20 (≈$14–23)
Adhesives and fixings
- Sika — Sikaflex 291i
all-purpose adhesive sealant for fitting hardware, 300 ml (10 fl oz)€8–15 (≈$9–17) - A4 stainless screws and rivets
screws, bolts and blind rivets in A4 steel for mast fittings (each)€0,50–3 (≈$0.58–3)
PTFE lubricant for tracks and blocks
- Anti-Salt Protector with PTFE
protective and lubricating spray with PTFE, for fittings and tracks€10–15 (≈$12–17) - Selden/Furlex — Lubricant
dedicated lubricant for sheaves, bearings and furlers, spray€20–28 (≈$23–33)
Ancillary materials and safety gear
- Abrasive paper, degreaser, masking tape
120–400 papers, cleaner/degreaser, edge tape (set)€15–40 (≈$17–46) - Mask with an A2/P3 filter, gloves, goggles
protection when working with two-pack paints and solvents (safety set)€30–70 (≈$35–81)