Sanding Gelcoat – No Pain No Gain!

After Milagros was sandblasted below, it was now time for the hull above the waterline. Sanding gelcoat was the order of the day. Instead of protecting our hull from water, the gelcoat of Milagros is instead literally absorbing it. Not good. The old, brittle, cracked and crazed gelcoat had to go. Of course, nobody could have guessed that this would result in injuries of all kinds.

Sanding gelcoat on our bluewater cruiser

We can’t say that the whole sandblasting action didn’t make us a little nervous. What would emerge from under the layers of color? Would we spot the first nasty surprises? Fortunately that wasn’t the case. The general opinion of everybody is: For a 40-year-old sailboat, our underwater hull is in very good condition. Lucky us.

What is that gelcoat stuff?

But now it was time for sanding gelcoat – away with the old stuff. But what is gelcoat anyway? Gelcoat is a synthetic protective layer of resin, that is applied to the fiberglass hull of a boat to make it waterproof and protect it from UV radiation. It also serves as a scratch protection. Better to scratch the gel coat than the fiberglass itself. It is applied with a brush and roller or with a spray gun.

Why sanding the gelcoat?

The gelcoat of Milagros is old. Very old. We assume that years or even decades of UV radiation have corroded and dissolved the protective layer of our boat to such an extent, that it has lost its protective properties completely. After none of our predecessors had done the job of sanding off the gelcoat, it was now up to us. So we got to work.

The horror stories don’t come true

We had read a lot of horror stories about sanding gelcoat. Depending on how thick the layers are on the ship, the work can become immeasurable. Nevertheless we started. Since we had bought a ton of sandpaper and all the other materials for sanding our antifouling anyway, we were well equipped. What followed was many days of dusty fun.


For the gelcoat sanding we used sandpaper with 60 grit and our Bosch random orbit sander. This was connected to an industrial vacuum cleaner to keep sanding dust at a minimum. And we were lucky! Although we were prepared for a lengthy process, we made better progress than expected. Bit by bit, Milagros was released from its old, useless coating. Meanwhile we heard postcasts and lots of music.

Our deep fryer is put into operation

The previous owner of Milagros lived mainly in the Marina on Milagros. Since he had unlimited electricity there, our kitchen is equipped with all kinds of gadgets. Among other things, he left us a deep fryer on board. Of course, this had to be tested. When sanding gelcoat for days, the culinary well-being must of course be taken care of to boost the morale of the gelcoat sanding crew. The first test was in the form of homemade French fries made from fresh potatoes. Or we tried Jalapeños in a beer batter. Awesome and delicious. Since Dave from SV Cavu asked for mozzarella sticks, we of course also tried frying those. What shall we say – we have never owned one, but a deep fryer is something really great and we are now busy deep-frying.

A deep-frying extravaganza

What is a “Bud Spencer and Terence Hill extravaganza” for our friends from the Cinéswiss podcast is a “deep-frying extravaganza” for us. We invited all Cabralians (a term for the residents of the Cabrales Boatyard) who felt like celebrating the discovery of our deep fryer with us. So we deep fried away in front of Milagros, and the evening was garnished by a Mario Kart tournament in the lounge. Thats how it is supposed to be!

We continue sanding gelcoat

Despite all the fun, we had to go back to work. Our experience with sanding gelcoat showed quickly – without diligence, we would go nowhere. If you want that stuff off your boat and decide to do it the sanding way, then there is no avoiding the fact that you will sand for many, many hours. There are no shortcuts and no tricks to get ahead faster. You just have to stick with it and not give up. Even if the motivation and desire diminish – even just an hour or two a day will bring you forward. Without perseverance, we would have given up quickly. But we also paid a price for our stubborn minds.

Suddenly, my neck hurts

After a few days of sanding, I woke up one morning and was in ruins. I must have pinched a nerve above my left shoulder blade during the night. Pati provided first aid. Had anyone heard me, police would have turned up with suspicion of murder. But despite all her massage skills, the following days for me were over. I have never experienced something like that. Pain all day and only limited movement. No more gelcoat sanding for me. Doctor Google said there wasn’t much I could do about the situation other than king pain medication and do some stretching. Bull****! Show must go on – Pati continued sanding and I devoted myself to office work (if you can call our blog and social media that).

Pati is not spared either

When I proved to be more or less useful again, the gelcoat sanding battle started again. We took turns sanding the gelcoat. The whole process was exhausting for both body and mind. Our heavy sander combined with the thick gelcoat layer – that was really hard work. Apart from my neck, Pati’s hands also paid tribute to the hours of vibration. After a few days she felt pain in her thumbs and had to take a break from sanding gelcoat.

An important tip for sanding work

Since I’ve worked as a painter in construction for many years, I have a lot of experience in situations comparable to sanding gelcoat. The most important tip I can give is: There is absolutely no point in saving money when it comes to equipment for larger and coarser sanding jobs. A good, professional sander is essential. There is no point in buying the cheapest sander on the market if it breaks after half an hour because the engine cannot cope with the load. More is more! In our case, we decided on on a Bosch ROS56VC even before we started our many jobs. This sander is relatively expensive, but worth every penny!

A Bosch  orbital sander ROS56VC sitting on an industrial vacuum
This thing is freaking amazing!

Luis is back!

In the middle of work, someone suddenly waved and called to us from his bike behind the boatyard fence. It was Luis who was on his break. On another day a car horn honked at us. Luis definitely has the coolest car in all of Puerto Peñasco. He drives an old, beautiful red VW Beetle. Of course, I had to text him immediately and told him that we wanted to come along for a ride someday! Said and done…

Old VW Beetle in Rocky Point, Sonora, Mexico
Coolest car ever!

Luis the professional

When we weren’t working on the gelcoat, we passed our days with other, more pleasant activities. So we went to eat with Luis in his mum’s restaurant, the Cenaduría Yoli. Funnily enough, we had diner there already when we first visited Puerto Peñasco in November. Of course, we went there in style in his red limousine. He used to play professional football (Soccer for our American friends) for 10 years with the Murciélagos de Sinaloa and Xolos Tijuana. Anyone who is bitten by the football bug knows that there is no chance of recovery. And so he still plays as on amateur level for the local football club called “Tazz”. He invited us to watch a game.

I love Football!

The match took place on a Sunday and was a treat. After a confident and controlled 2-0 lead by Luis ’ team at halftime, the two sides ignited the turbo in the second halftime. 7 goals, 3 red cards, two penalties and a brawl after a foul resulted in a 3:6 defeat. Unfortunately, Luis’ team had nothing to oppose to the much younger opponents towards the end of the match. The legs were getting too tired. Finally some football again! I miss the stadium visits at my beloved FC Basel at home in Switzerland. I can hardly wait when the time comes again. Who knows when that will be. Until then, I’ll just watch Luis’ games here in Mexico.

But the gelcoat sanding is lurking

After the game we continued sanding the gelcoat. Unfortunately, we could only escape from our refit obligations by the hour. We advanced well and Milagros looked completely different. She’s no longer white, but dark blue in with Dalmatian look. A small problem still came up. We couldn’t tackle a small indentation on the upper edge of the freeboard with our large Bosch sander. As so often, Dave from SV Cavu came to the rescue. With a small Black + Decker Mouse Sander (that I can also highly recommend), we were also able to sand away this little bit of gelcoat.

The hard work is worth it

And then: Done! Out! Finished! Done! Adios! Au revoir!

We don’t even know exactly how many hours went into sanding the gelcoat. It was many, that’s for sure. We ate dust for over a week. My neck is still reporting to me all day, but I’m much better.

No pain, no gain. It pays off to keep on keeping on, even if it hurts.

Sanding Gelcoat of a sailboat

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Gratulation, gute Arbeit! Ist Jalapeños im Bierteig das neue Pendant zur Grundulla? Freue mich auf die Abstimmung zum neuen Lack, ich wär dann für Neongelb – oder für Dave rot-blau. Viel Spass noch, aber den habt ihr ja allem Anschein nach. Gruess Romano

Hoi Romano, wir haben noch keinen Namen für unser zusätzliches Food Truck-Projekt. 😛
Für die Farbe der Hülle: Weiss it is.

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