Bare metal repaint

People often wonder about the boat painting process - how long does it take? What stages are involved? Do I need to go back to bare steel? How should I protect against rust etc.? This post outlines some of the practical steps, technical processes, and key considerations and learnings based on my recent experience repainting a client’s 57ft trad-style narrowboat in the Highline Yachting wet dock at Packet Boat Marina.

A visual summary of what we were able to accomplish within two weeks

The first step was to determine the scope of the work and to draft a methods document that would act as a roadmap for the two-week project. Based on the condition of the paint and underlying steel, the decision was taken to remove the existing paint completely, rather than simply sand the existing paint back, to allow the steel itself to be treated, protected, and then re-covered.

Our methods document & risk assessment can be downloaded here for reference and information.

Detailed schematics were used to calculate surface areas and paint quantities

The main practical limitation of painting boats at this time of year (autumn) is the weather - neither rain nor cold temperatures are conducive for painting outside, meaning the use of High Line’s wet dock was a good solution. We were lucky to bag a two-week slot between several other bookings, which gave us our time limit. So how much would it be possible to do in two weeks?

We were not entirely sure, as there are so many variables and unknowns until you actually get stuck-in, so we focused on clear priorities and an understanding of “what good would look like” when the two-weeks was up. The main priority was durability and longevity (focusing on preparing and conditioning the steel surfaces), and ensuring sufficient layers of paint could be reapplied to protect it against the elements.

Based on the priorities, time constraints, and other practical considerations (including factoring in paint drying time etc.), we decided we would be aiming for: (1) One coat of rust inhibiting Owatorol oil (applied directly to the bare steel after all rust had been removed); (2) One layer of primer (with 25% Owatrol to further enhance the rust-protective properties of the Zink-based undercoat); (3) A minimum of two (blue) top-coats.

We knew from the paint supplier (SML Paints), that our chosen Oxford blue (Jotun, single pack, oil-based topcoat) would require a minimum of three coats to achieve the desired consistency and finish (we learned that blues tend to have a lower pigmentation and therefore poorer coverage than other colours). As such, we knew that we would need to factor in at least one more week in the Spring to apply the final blue topcoat, reapply the decorative stripes, decals and signage, and get non-slip layers on the gunnels and roof.

A two-week transformation, back to bare steel, oiled, primed and re-painted

Some of the key learnings/ takeaways from the intense two-week blast in the wet dock were: (1) that a scabbler is an essential (albeit rather expensive) tool for effectively removing all old paint, (2) that Owatrol oil is highly effective for rust prevention (applied neat to bare steel, and mixed using a 25% ratio with primer) and improving paint flow (5-10% in subsequent coats), and; (3) that things always take longer than you think when you’re working with such a vast surface area and products that can often take 24-48 hours to go-off.

Overall, we were able to achieve our two-week objective and the boat floated out of the wet dock with all the layers we had hoped to apply. Our final challenge was moving and mooring the boat back without scratching any of the new paintwork. While paint often dries relatively quickly, it can take many days/ even weeks to fully harden so that it’s protected against ropes and fenders rubbing etc.

Safely back on her home mooring in the marina, awaiting her final coat and finishing touches

With thanks to my client for a fantastic collaborative experience and the opportunity to work on their lovely boat, High Line Yachting Ltd. for the use of their wet dock, which dramatically boosted productivity and protected from the elements, and to my many informal advisors and mentors who fed in along the journey and contributed to such a successful two-week outcome.

The (grubby) face behind the camera!!