• Sailing The Dream

Building a hardtop - costs, other numbers and conclusions (part 6)

Now that The Dream hardtop is built and has been installed for over 9 months now, tested in strong winds both at anchor and at sea, it is time to talk the juicy talk.

Costs for the construction of both the fibreglass and stainless steel structures, lessons learned and future works.

It is also time to do a cost comparison between our DIY construction and the quotes we received for the same design from the professionals.

We will also talk about the difference in weight between the original Bimini and our DIY solar arch to the new structure and the performance differences.


The field tests

During the three months immediately after the installation of the new hardtop, we suffered at anchor several storms in Turkey.

The strongest and probably shortest-lived one brought gusts up to 54 knots that caught us several times sideways, the ones that followed although more long-lived had winds slightly weaker (upper 40s) and more consistent.

On all these occasions the entire structure faired very well showing us its benefits.

Sea trials

Late in March we departed Turkey, and of course, the winds in the Aegean turned out to be quite different from what we anticipated, and the sea state become extremely choppy and uncomfortable. The new hardtop however didn’t show any signs of stress or movement, giving us a much more protected feeling than the original Bimini had ever given. No rattle or shake!

By the time we started crossing the Ionian we knew we were up for a ride, and oh what a ride it was. The winds got to nearly 40knots, the waves quickly followed and in no time at all we were surfing in between waves of 5 to 5.5 metres on very short periods. With the old Bimini and solar arch at that point we would be seriously thinking about when would it all come loose and be lost, but with the new hardtop despite our concerns all was fine.

The hardtop felt sturdy in place showing no signs of stress whatsoever.


Extreme weather trials

Still, while we were in Turkey, in the first storm we got not only very strong winds as mentioned, and extreme downpours, we got big hail. Roughly 1cm diameter!

Some of the biggest hail we have ever experienced onboard, to the point we were very worried about the plexiglass hatches, the huge skylights we have in the galley and our solar panels. At this point, we wondered if it had left marks or dents on our fibreglass job, but no! All was good, and no evidence of the previous night could be seen.


Safe to say that with all these experiences we considered the new hardtop tested to our satisfaction!


Overall weight

One of our biggest concerns, when we embarked on this project, was how much weight we would potentially be adding to the stern of the yacht. After all, we already added three solar panels weighing each 22kg.

While we were designing the new structures we worked on an estimate of the overall maximum weight based on the specs of each material/product we were planning to use (excluding the paint because we only got the specs of that just before painting). 70kg maybe 75kg was the maximum weight we had expected for the fibreglass hardtop.

(All this information is detailed in the table at the bottom of this post)

At this point, although we already had a decided stainless steel structure design (to support the fibreglass hardtop) we had not yet given much thought to how much it would weigh.

As we started the actual construction we made note of all materials used and assessed the wastage and dry weight (after solvents evaporate) including the paint. This gave us a reasonably accurate estimate of the final weight.

The estimated final weight of the fibreglass structure is 70kg.


Once we had the fibreglass structure completed it was time to focus on the stainless steel structure. We had designed a tubular structure of 38mm diameter and 3mm thick and very beefed up mounting plates and brackets to ensure it was sturdy enough for offshore. The new stainless steel structure and connection pieces weigh a bit more than 35kg.


With all this calculated the total weight of the new structure is shy of 107kg (estimated).


This sounds like a lot at first but when you look at what was done you realise that is not that much.

But how does it compare to the original canvas Bimini, and let’s not forget (DIY) solar arch?


After removing all the components of the old structures we decided to weigh them to assess accurately the impact of the changes.

The first item we focused on was the actual canvas to our surprise it weighs 9kg!

Then we checked the weight of our DIY solar arch built way back in 2019. That was easy as we had done that exercise at the time, so it was a matter of checking our spreadsheet for that project. The solar arch weighed 35kg. (Solar panels excluded)

Now we only needed to assess the actual original Bimini frame, and that was a big revelation.

It weighed roughly 60kg of stainless steel.


The total weight of the set-up we had just removed was between 100-105kg!


To our surprise the weight difference between the old set-up with the original Bimini and the new hardtop was negligible.

The benefits of the new set up were much more than the negatives in our opinion.


Cost of Professional Built vs DIY Built

The first times we thought about this project we always wondered if we were going to build it ourselves or if we would engage a company to do it.

As we started putting our ideas into CAD (computer software we used to draw in the construction/architecture industry) and getting to a very good idea of what we wanted, we also started contacting fibreglass builders for quotes (using contacts friends had used for their projects) in different parts of the Mediterranean.

The prices seemed to range between 15k and 20k euros, stainless steel structure excluded.


We knew perfectly well that the material costs for us would be around 10% of that, and the professionals would get a better price from their suppliers. It felt utterly disproportionate.


With our decision of doing it ourselves, we tracked the price of all items purchased and all items used. Indeed the final cost of the fibreglass construction was around 10% of the numbers quoted including all consumables and protection gear.


When it came to the stainless steel structure we also got all sorts of crazy quotes, but with a bit of shopping around and scheduling works for the low season we managed to keep it very reasonable, and some might say a bargain.


The professionally built hardtop including a new stainless steel structure would have cost us around 22k euros.

The DIY-built hardtop including the new stainless steel structure cost us just under 2380 euros!

Things we would have done differently

The first and most significant thing we would have done differently would be to build it in a proper workshop or even a makeshift shed. More specifically the important thing would be working on a levelled surface instead of trying to overcome the shape of our cabin top. A proper workplace would also mean better drying times and less stress with the weather.

That would have prevented a lot of the challenges and subsequent imperfections we had to deal with.

We would invest a bit more time and effort in the fairing process.


These two aspects alone would have made possible a perfect-looking structure.


The challenges we set ourselves and some impatience on the fairing means we nailed 90% of our intentions.

We should have faired the underside of the structure instead of just painting it, but that is just a matter of looks, nothing critical. After all, the idea had always been to install a false ceiling structure to give a nicer feeling in the cockpit.

Unfortunately, we struggled to find material in the size we wanted and had to settle for a different size to avoid seams we knew would be difficult to deal with.

When we left Turkey the underside was still just painted with the white colour undercoat, but during the time we were in the boatyard in Lisbon we painted what would become the exposed areas after the false ceiling installation in the same grey colour from the top side. That minimised the perception of the imperfections that we hadn’t corrected by choosing not to fair the underside and provided a cool contrast between the two surfaces drawing attention towards the white PVC boards used on the new false ceiling.


For the installation of the false ceiling, we found some PVC slates we glued with a specific glue and screwed to the hardtop. The PVC boards were then installed onto these slates.

The installation of the false ceiling turned out really good, so good we even changed our lighting plans/design and went for a much easier solution with the LED strips simply glued on the top side of the panels.

Although the false ceiling turned out quite well, and we are quite happy with the effect, what we are not happy with is the final colour of the paint.

The grey colour turned out to be very much like the navy grey used on military vessels, and that was quite unexpected. We did check the grey at the shop against a fabric sample or canvas, and seemed close enough, but after painting, it felt like it expresses a lot more blue, which is great when we don’t have our shade curtains on because the hardtop blends with the horizon (very much like the military vessels).

A new paint job is on the cards, and after getting a few more colour swatches we picked a new colour, which we now have a pot ready to go.

Let’s see how that will turn out at a later stage.


***You can find other posts of this series at Building a hardtop - the idea, concept and material choices (part 1) , Building a hardtop - the construction (part 2) , Building a hardtop - Fairing (part 3) , Building a hardtop - joining the pieces and painting (part 4) or Building a hardtop - stainless steel works and installation of equipment (part 5)

***In the spirit of sharing our dreams and experiences we have shared this blog post in the NOFOREIGNLAND.COM website sailors community.

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