Painting Wooden Hulls: History and Techniques of Stoppani’s “Riva Cycle

Painting boats is a crucial process, especially for wooden hulls, which require a higher level of protection against the corrosive action of sea salt. Stoppani was the first company to deal with the painting of wooden hullsThe Lechler Group is still the undisputed leader in this sector today. This story, which dates back to the 1960s, tells the story of an entire era in the nautical industry, which continues to this day.

The history of Stoppani and Riva

In the early 1960s, the famous Riva shipyard decided to take a decisive step forward by contacting Stoppani to develop a top-quality paint cycle. The aim was to resolve once and for all the technical problems the yard had encountered in previous years. Stoppani then formulated the “Top ClassStoppani’s “Top Class” was then applied to all Riva’s works of art, becoming their sole supplier of paint products. This is how the meeting between Stoppani and the Riva shipyard, both based in Sarnico. Since that day, their stories have been intertwined in surprising ways; so much so that to this day, the process of painting Stoppani’s wooden hulls is still called “painting”.Riva cycle“among industry professionals.

Since 2007, the renowned Italian company Lechlerbased near Como since 1910, has also become a major player with the acquisition of Stoppani. From the outset, Lechler has made research and innovation its mission, and today boasts an international reputation. For its part, Stoppani, thanks to Lechler’s technological support, offers a catalog of state-of-the-art products and paint cycles for yachts and motor and sail yachts, with high-tech materials and approved products for the restoration of precious historic boats.

Painting wooden hulls

As yachting enthusiasts well know, it’s becoming increasingly difficult to find suitable, quality products on the market for restoring wooden boats, such as vintage Rivas, which are becoming increasingly rare due to the high cost of production and maintenance. Faithful to its vocation as ainnovation and tradition“Alongside its innovative Isofan Marine ranges for yacht painting, Stoppani has always retained traditional products for the restoration and maintenance of wooden boats. In fact, all the original products in the cycle used to make authentic Riva hulls are still available in Stoppani catalogs.

Restoring a Riva wooden boat is a very delicate undertaking: it must be entrusted to skilled professionals. skilled handscapable of skilfully handling the original materials used for decades by the Riva shipyard. Extensive research and historical reconstitution have enabled us to reconstruct and make available to restorers the original materials and restoration cycles for Riva period boats. These cycles can also be adopted for all other manufacturers’ hulls and boats made with precious woods.

painting of wooden hulls on historic boats

How the “Riva cycle” works for painting wooden hulls

Stoppani’s painting techniques for wooden hulls comprise five main stages:

Dead work: stripping, color restoration, wood impregnation, filling, finishing.

Living work wood impregnation, filling, finishing.
Waterline
Additional elements (subfloors and interiors)
Teak Life (Stoppani’s special treatment for precious woods)

When restoring Riva historic boats in “exposed” mahogany, preparation of the hull is essential. Surfaces must be treated with the utmost care, using suitable materials and equipment.

The stages of the original Stoppani cycle, which Riva has always followed in the production of boats in precious woods, provide for specific treatments for each part of the hull. Before proceeding with the preparation and painting operations, it is important to ensure that the condition of the wood is good enough to allow the paint to be restored. If conditions are critical, carpentry work is required, including rebuilding damaged planking.

Dead work

Preparing and painting thestill life include several intervention stages:

Stripping

Color restoration

Wood impregnation

Filling

Finish

For the strippingIf the painted surface is in good condition, simply sand the surface thoroughly, then move on to the finishing phase. On the other hand, if the surface is in poor condition, it is necessary to completely remove all layers of pre-existing products, either by dry sanding with P40 grit sandpaper, or by using a suitable stripper (flame stripping is not recommended, as it can leave marks on the wood surface that are difficult to remove later). The stripper should be applied directly to the surface to be stripped, allowing it to work in deeply, then removing the wrinkled film with a scraper. If the thickness is significant, the operation can be repeated until the film is completely removed (2 to 3 times). Once removed, wash the surface with LSM00800 DEGREASER solvent, using a clean cloth. Allow to dry thoroughly, then dry-sand the surface with P80-120 grit sandpaper.

If, after removing coats of paint, the surface shows black spots due to wood oxidation, it is advisable to remove them using the specific whitening product S86181 TEAK LIFE.

If you need to restore tone and uniformity to yellowed or discolored surfaces, you can darken the wood grain with S71070 PASTA MOGANO 2527 according to the following procedure:

Mix the MOGANO paste thoroughly.

Add the specific catalyst to the MOGANO paste in a large container. S71071 SOL.B in a volume ratio of 3:2.

Mix.

Dilute the mixture 1:1 with Nautica thinners. S70060 (911) or S70030 (371).

Brush a coat of the mixture onto a limited area to be treated.
Even out the color by immediately swabbing with a suitable pad soaked in the same solvent used for dilution.

After color restoration with MOGANO paste, without further sanding and after allowing 6 to 12 hours to pass, you can move on to the impregnation phase by applying three coats of S68030 (2:1 catalyzed polyurethane clearcoat 910) with S68031 SOL.B. This varnish, used as an impregnator, should be diluted 50% with S70030 thinner 371 (for brush or roller) or with S70060 thinner 911 (for spraying). The three coats should be applied with an interval of 2 to 3 hours between each. This procedure can be carried out on all clear-finish parts to be restored, whether exterior or interior.

Then it’s time for the filling. After waiting at least 24 to 48 hours, sand the surface with P320 dry sandpaper, then clean the surface and begin the filling and finishing preparation phase. Always use S68030this time diluted from 20% to 40%, for a total of three further coats, also applied 2-3 hours apart.

After waiting at least 24 to 48 hours after the three daily passes, dry sand with P360 grit sandpaper and proceed in the same way until you obtain a full, glossy, even surface. The original Riva cycle includes 6 to 7 steps for a total of 18 to 20 coats.

At this point, you can proceed with the‘application of the finish on the hull, by applying 2 to 3 coats of high-resistance, UV-protected clear varnish S68096 GLASSTOP CLEAR UV2:1 catalyzed with S68099 SOL.B and diluted to 15% with thinner S70030 371 (by brush or roller) or with thinner S70060 911 (spray-on), with 24 to 48 hours between coats, after sanding each hand with P600/800 dry sandpaper.

Any imperfections can be removed by sanding with very fine P1200-2000 or Trizac® sandpaper, followed by polishing with a roto-orbital machine and the 00917 LECHLER POLISH.

The living work

Preparing and painting the‘living work include the following steps:

Wood impregnation

Filling

Anti-vegetative finish

Waterline

For this part of the hull, it’s also necessary to check the condition of the existing paint (if the surface is in poor condition, proceed as for the dead work explained above).

The process begins with the;wood impregnation. For impregnation treatment of live wood, on a raw wood substrate, start the painting process by applying a coat of anticorrosive primer S27115 2000 diluted 20% with thinner S70120 6400/D. After drying for at least 12 hours, continue with dry sanding using P400 sandpaper, followed by a second coat.

Then dry sand again with P400 sandpaper and apply S28060 RESOLUTION PRIMER diluted 10% with S70120 6400/D thinner. After a further complete drying time of at least 24 hours, finish by applying two coats of anti-vegetative at 24-hour intervals.

The waterline

As far as the waterline is concerned, after a dry sanding with P360 grit paper, it is necessary to apply a coat of S24080 SOTTOFONDO 912 White catalyzed at 40% with S24081 and diluted at 20% with S70060 911 thinner to the transparent finish of the dead work (S68030 VERNICE 910).
When the undercoat is completely dry, sand it with P600-800 paper and apply 2 coats of GLASSTOP two-component enamel in the original tone.

Complementary parts for painting wooden hulls

Finally, here are Stoppani’s indications for the complementary parts in the painting process for wooden hulls. On subfloors and hull interiors, after the impregnation phases, dry sand with P360 paper and apply two coats of S71090 CLIPPER Grey Interior Hulls 8257 single-component topcoat at 24-hour intervals, diluted 10-15% with S70120 6400/D thinner.

For precious woods, as mentioned, Stoppani offers a specific treatment. Visit precious woods used in the nautical sector (teak, mahogany, iroko, etc.) are generally not treated with paints; however, exposure to direct and continuous sunlight impoverishes the fibers, causing the essences to lose their essential oils. We therefore recommend periodic treatment with specific products from the TEAK-LIFE line: