On the Job

How to Fix Scratches on the Yacht’s Painted Surfaces

4 May 2021 By Capt. Mx
Capt. Mx gives the lowdown on how to fix up unsightly scratches in the paintwork on board a boat

Still pushing water, having enjoyed and excelled aboard square riggers, Whitbread Maxis, the world cup circuit when there were only 7 boats, America’s Cuppers, 12M, modern classics, real classics, salvage, racing, passage, refits, builds and more, for 38 years, 54 Atlantic crossings, 48 world championships, and a few stories more. I enjoy the serenity and clarity that a life between the blues offers, washed by wind and waves, where all that remains is the simple truth of all things, questions for all things technical, and acceptance of all things magic. 

Capt. Mx gives the lowdown on how to fix up unsightly scratches in the paintwork...

You spend much of your time caressing your topsides and keeping them pretty, but all it takes is one cocktail party or beach day for those inevitable scratches. It takes finesse to make your painted surfaces shine again.

Damage can happen so easily, whether it’s from dirty feet after the beach or something more. These scratches are often light and can be readily polished out. Typical polishes are equivalent of 1200 to 1600 grit sanding, although in a paste that spreads easily and reduces friction as you work.

However, if the scratch is a bit deeper, it may be a good idea to begin with a paste compound rather than a polish or wax. Address the scratch first and beautify after. I suggest 3M Finesse-it Marine Paste Compound: a gallon container is always good on the boat as it quickly addresses any slight scratches, such as those made with sandy feet, and it works well on the most heavily oxidized surfaces.

You can achieve good results with effort, clean and dry cotton rags, or perhaps even a machine (although you would have to consider the speed and material used). To keep it simple, a polishing wheel on a drill may be best, as you can control the speed and the area affected, so get a polishing kit before you go.

Once you can no longer see nor feel the scratch, use a polishing wax or finishing glaze; there are many, including the 3M range, that I like very much. This will help revive the shine and may be used on small surfaces up to an entire cabin top, as needed.

Sometimes, the scratch is deeper than what can be repaired by paste and polish. You’ll likely see the clear-cut line where it has passed through the paint layers and has gouged the base material, filler, carbon, aluminum, or other. In this case, get your painter’s cap on and pull out the necessary materials, including blue tape, clean, dry cotton rags, acetone, fine-brush kit, and the primer, paint, and catalyzers required. You’ll also need sandpaper and the grit determined by the gouge or scratch (but certainly up to 800 or 1000) before you finish. Always wear a mask (even with a slight breeze, and certainly if under cover) — these materials are toxic and may turn your toes green.

Tape off the area, clean it completely with acetone and a clean cloth, and begin sanding with one finger and the necessary sandpaper, anything from 80 or more. But remember, everything you sand off, you have to put back on. Once the area has been prepared and has no sharp edges, wipe again with acetone and cloth, let dry, and prepare to apply the correct primer with the brush determined by the extent of the damaged area. These are moments where finesse makes all the difference.

Read all instructions for every product and allow time to dry. Accomplish all actions within the working time allowed — dependent on temperature and ventilation — and once complete, you should have the damaged area prepared, primed, and painted.

You now only have to sand diligently to restore the smooth surface and apply the paste and polish to revitalize the shine that will become the hallmark of your work on deck.

This column is taken from the February 2021 issue of Dockwalk.


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