Many of you will be familiar with Turkish Map Fold style books if not by name perhaps by having one of these as a map when traveling.
Team Möbius got our Arch on Möbius in place this week and the all the many functions we have been able to incorporate into the design of this arch it reminded me of the Turkish Map folded books and maps I’ve had and always been fascinated with. Seems only appropriate that our Turkish built boat would have a Turkish Fold style Arch and hence the title for this week’s update.
You may recall seeing this little animation in an update a few weeks ago and show is always better than tell so I’ll use it again to help you understand how our folding mast works. Burak kindly put this together for us as we were testing out different configurations and dimensions of this whole system.
The video makes it all look very simple, and it is remarkably simple but getting the geometry just right so everything fits and clears and the roof ends up in just the right spots when fully up and fully down was tricky and hats off to Dennis, Yiğit and Burak for getting this to all work out so well.
We have gone to this significant amount of work to design and create this folding Arch & SkyBridge roof in order to give us two very significant features or modes:
1. Canal Mode where by lowering our Air Draft, the distance from the Water Line to the top most part of the boat we will be able to cruise in areas such as the canals or small inland rivers and water ways which have low fixed bridges you have to be able to pass under. Our Air Draft with the Arch and roof folded down will be about 4.2m/13’ 6” compared to about 6.4m/21ft to the top of the raised Arch, and then the Paravane poles add about another 2m/6.5’ on top of that.
2. Hunkered Down Mode where we can dramatically reduce our windage, the side area, when we are in areas during cyclone and hurricane season. Christine and I have spent quite a bit of time in such areas both together and when we were single handing so we have first hand experience with the power and the danger which these severe weather patterns possess such as the 285 km/h winds we saw when Cyclone Winston hit us when we were hauled out on Learnativity in Fiji in 2016. By dropping our height and essentially eliminating our SkyBridge and putting plywood or Lexan storm coverings over all the Pilot House glass we stand a much better chance of surviving such forces of nature with the least amount of damage possible.
You saw some of the components of this arch being prepped last week as Sezgin and his TIG welder made quick work of welding all the many joints where the various diameter pipes all connected.
Those have all now been lifted up onto the SkyBridge for assembly into the finished arch. Here is one side of the vertical legs of the Arch being stood in place.
and tacked to the upper half of the big hinge plates on either side.
Uğur and Nihat finished cleaning up the upper arch member with brass wire wheels….
….. and set it atop the two vertical legs, got everything all squared up with the laser level and tacked in place.
Stepping back on the Aft Deck you can see how the vertical pipe legs of the Arch continue below the hinge plates to transfer most of the loads down to the eXtremely strong hull framework and make this arch essentially part of the hull itself.
The vertical pieces under the Aft Deck roof are temporary braces to maintain its location prior to having its supports down to the Engine Room Vent boxes a bit later.
Looking up from the ground will give you another perspective on the Arch in place as it awaits fitting the SkyBridge roof structure and testing out the whole folding mechanism.
This view from the forward Port corner of the SkyBridge provides a good perspective of the size and scale of the Arch. The rectangular opening in the middle is where the comfy Captain’s chair will sit to create the upper Helm Station and the circular stairs you’ve seen in previous weeks is over to the left in this picture and leads down to the Aft Deck.
Moving aft and standing just behind the Arch provides another view of the SkyBridge layout. The rectangular holes in the bottom of the Arch top plate creates room for me to work on the many items mounted up here such as Radars, AIS, GPS and many antennae. There ware slots in the pipe which you can see in the photo above where all the wiring will be very safely carried down inside the Arch tubes to the electrical panel that sits down below the deck where the Port Arch legs attach.
With the Arch all tacked up we could carefully fold it down for the first time and tweak the alignment and fit to get everything just right.
This is about how the Arch will sit when it is fully folded down with the SkyBridge roof fame attached.
From a distance and slightly under water level it looks like this.
Next up we will lift the SkyBridge roof fame you saw being made a few weeks ago, lifted up and fasted to the Arch so we can test out the whole Turkish Map folding system.
Never being ones to rest, Uğur and Nihat were also busy folding up the 6mm aluminium plates that will become the two large Engine Room vent boxes on the aft deck.
This is the ER vent box on the Port side …..
…. and this is the Starboard side vent box.
The cut out area is where our BBQ will be mounted as these two vent boxes will serve double duty as our outdoor Galley with sink, cutting board and storage to join the BBQ.
This rendered view will help put this all into perspective with the two ER Vent boxes in red. Mist eliminator vent grills will be on the inside surfaces to keep salt water and humidity out and inside each box is a set of baffles to direct air in and out of the ER and others to bring fresh air into the Guest Cabin and Christine’s Office.
The other exciting development this week was the arrival of this truckload full of ……….
………….. can you guess???
The busy little worker ants they are, Naval people appeared out of nowhere …..
…. and within minutes they had the full load moved from here ……..
……. to here.
Did you guess what all these bags are full of?
Correct! It is all our EPDM foam insulation. Most of this is 50mm/2” thick which covers all the interior hull plates, underneath all the deck plates and in the interior walls …….
….. with some 10mm / 3/8” for covering the aluminium stringers and frames so let’s show you how this all works.
We experimented and consulted with the manufacturer of the EPDM foam and came up with a 3 stage process.
First the horizontal stringers are have lengths of 10mm EPDM fully wrapped around them and glued in place with a special contact cement.
Second, more lengths of 10mm EPDM are cut, fitted and
…… glued to the frames.
With all the stringers and frames covered the 3rd step in the overall process is to cut, fit and glue the 50mm EPDM to the aluminium surfaces.
Here is a small test area in the aft Port corner of the Workshop with all three steps completed between four frames and two strips on the ceiling. 
This is a very laborious process as there is a LOT of intricate fitting to the different shapes, sizes and openings that need to be carefully and completely covered. It is important that the adhesive covers every bit of the aluminium and foam so there are no air bubbles trapped underneath to ensure that no moisture can get in and that there are no thermal bridges created between the aluminium components and the interior spaces and cabinetry.
You will be seeing lots more of this process as it progresses over the coming week and I can explain more about why we are going to such pains to put in this type of insulation and why we believe insulation is one of the most significant factors in making these kinds of eXtreme Passage Makers so comfortable and so efficient in both eXtremely hot and cold areas in the world.
Saving the best bit of progress for last here is this week’s boatload of cuteness to let you know that the Dinc twins Mert and Yiğit also continue to grow and develop eXtremely well.
I hope you are enjoying seeing this all unfold as much as we are and that you will continue to follow along with the whole process of building our just right, just for us Goldilocks boat.
See you next week!
Is there not a spray foam version of this that would greatly reduce the labor intensive cutting, fitting and gluing?
Hi Elton and thanks for reminding me of the fabulous work you did on that CBC generator truck.
We have spent a LONG time figuring out the best way to build a Thermos bottle shaped like a boat and it pretty much came down to the two main choices you highlight; glued on sheets of EPDM or SPF Sprayed Polyurethane foam. Both have been used extensively in new boat construction with SPF dominating for many years but in the last 10 or so EPDM has become more popular.
I am very familiar with SPF having used it in home applications as well as being how our previous boat Learnativity was insulated. It served us very well and so was definately in the running for Möbius as we did our due diligence and research for the just right, just for us choice for insulation.
SPF has two major advantages in our situation, the one you noted of MUCH easier and faster installation and the other is that it has a higher R value for a given thickness. However it has several disadvantages for our application which caused us to chose EPDM. The primary ones being that over time, measured in years, it does absorb moisture, it is difficult to know if any voids or air pockets have been created between the SPF and the surfaces you spray, the outer surfaces are very rough and uneven and it is a bear to remove when you need to repairs or modifications afterwards. And you need to factor in quite a few hours for cleaning up the overspray inside a boat and shaving down foam where it has expanded over areas you need to fit other parts into.
EPDM’s primary disadvantage is the laborious installation it requires but it has a zero moisture absorption factor even when immersed in water and is easier to remove spots in the future if needed. EPDM also has a slightly higher acoustic dampening factor. These tipped the scales for me and so we have gone with EPDM. We have also gone WAY overboard, sorry couldn’t resist, with the amount and thickness of the EPDM we are putting in. Recommended thickness by the manufacturers for our application was to use 20-25mm / 3/4-1″ but we are doubling this and using 50mm/2″ EPDM. I will expand on all this more in future updates on the blog but Learnativity always lived up to her name and taught me a LOT and one of the biggest lessons over time was the advantages of a super well insulated boat. It has such a ripple effect of increasing the overall efficiency of the boat requiring so much less energy to both heat and cool the interior and it dramatically increases the comfort of the boat both thermally and acoustically. With the zero moisture absorption factor we can also run the EPDM down much closer to the few areas we have in the interior where water could pool so we get even more insulation this way as well. And given that I’m the guy that has to do all the maintenance and modifications of the coming years the ease of working with the EPDM is a big factor for me as well.
On the bulkhead walls we will double up even more on the acoustic insulation by creating a layered combination of different plies of foams, trapped air and wood. Some of this will include the type of sandwiched lead you referred to and we expect that each cabin area will be extremely quiet with full sound separation between them. Over the years I learned what a difference it makes to have a quite boat so I’m putting as much emphasis on acoustic insulation as thermal. A quite boat, especially when underway and now all the more so with a power boat rather than sail, is so much more enjoyable for me and when the poop invariably hits the fan at O dark Thirty in the morning I’ve also learned how much sound is a factor increasing stress levels for those aboard dealing with the situation so I regard acoustic insulation as one of the many ways we are making Möbius the safest boat possible.
Well, way too much information as usual from me but thanks for your thoughts and please do keep up your critique and suggestions Elton, and others, as I value them very highly and learn a lot from all your input.
What is the name of the glue you use for the EPDM rubber when sticking it to the aluminum? Looking to do something similar to enhance my insulation. Thanks!
I believe each of the companies making EPDM foam offer and recommend their own brand of adhesive but to the best of my knowledge, research and testing it is all pretty much just good quality contact cement and that is what we are using now for installing all the EPDM insulation to every internal aluminium surface. Hope this helps and best wishes with your insulation project.
How heavy is that thick insulation?
Hi Jo. We are using a range of thickness of EPDM from 10mm for wrapping around the stringers and other short thin parts of aluminium and then 50mm for the rest. To increase the insulating effectiveness the manufacturers also vary the density such that thicker insulation results in lower density whereas thinner insulation results in higher density. For thicknesses below below 32mm the density is 48-80 kg/m3 while wall thickness above 32mm, the density ≥ 40 kg/m3.
We pay a great deal of attention to the weight of every single thing we put into the boat and treat weight like a budget wherein we save weight wherever we can which allows us to “spend” some of our savings in places that warrant it. In the case of the EPDM insulation the vast majority of it is carried very low in the boat, mostly on the sides of the hull and undersides of the deck. Overall we see the weight of all this EPDM to be a good investment of our weight budget and it is not significant relative to the weights of other materials, equipment and fluids. The benefits of our eXtreme degree of insulation FAR outweigh the weight factors and pay us huge dividends throughout the whole life of the boat with dramatically lowered energy requirements to keep the interior living spaces at a constant just right temperature and humidity level in even the most severe hot and cold climates, close to zero maintenance and an almost eerie degree of quiet onboard even when running at full speed in open ocean conditions.
Thank you for clear reply, do you know are “less density” thicker foam structure more sponge like that there is “holes” witch may absorb liquid, ( the material itself is not hydroscopic but does the “structure” kind off suck water inside? Do you know the differ in U-value between 10 and 50? Did you use armaflex or other product? Thanks for informative blog!
Hi Wayne, thanks for sharing in so much detail the ongoing progress of your boat and the decision making process behind the design and construction. Your documentation is highly instructive for those of us contemplating (or dreaming about) similar future projects.
When you were evaluating insulation systems, I’m curious to know whether you considered the system used by Boréal Yachts. As I recall, they spray the aluminum interior with a thin layer of adhesive cork particles, to eliminate thermal bridging, and then infill all spaces with hand-fitted sheets of extruded polystyrene (XPS). A total of 3″ of XPS is used, with any gaps between panels filled in using some kind fo spray foam.
Using EPDM as hull insulation was unknown to me prior to reading your post, so thanks again for sharing!
Hi Scott. Thanks for this feedback that these blog posts are proving to be helpful and valuable to you. That is a big motivator for me as a large part of doing this is to add my contribution and “pay it forward” for the many others out there who have shared their journey and learning and from which I have learned so much.
I was aware of this system that Boréal uses but I didn’t feel that it would fit our use case very well. I’m always very reluctant to use any painted coatings on aluminium as my experience so far is that very few coatings will stick to aluminium over the long haul, measured in decades. In the case of insulating the interior surfaces of an aluminium boat this is particularly critical as there is really no way of inspecting the aluminium surface once you’ve got the insulation in place. So if that sprayed on cork doesn’t stick or starts to come away or degrade you’d never know it and could be allowing moist air in which sets up some nasty corrosion over time. Boréal builds very high quality boats and so I’m sure they go to great lengths to both apply the cork very carefully and then seal the whole insulated cavities very well so this would be an unlikely scenario I agree but not one I was willing to go for.
I looked at using foam board type materials such as XPS but by their nature they are very flat and so when put against curved and welded aluminium panels there will always be some air gaps and that’s a big concern for me. The use of the spray in place foam would provide some good insurance that these air gaps would be sealed from any air movement but I would worry about this holding up over the decades I’m expecting to get out of this boat.
EPDM has a degree of dependence upon the adhesive used to have it stick to the hull and aluminium surfaces but my conclusion was that it is important to have the insulation be well adhered to the aluminium by some means and this is the best I’ve been able to find. The very spongy nature of EPDM makes it very easy to have it form precisely to pretty much any shape including very irregular ones around frames, over welds, etc. so as long as you take the time to ensure that the adhesive is very thoroughly applied and that you carefully press all the surfaces against the aluminium then my tests with this and other research shows that it sticks very well and stays stuck over time.
Discussing this with high end boat builders and visiting several of their facilities and boats EPDM was pretty much the go to material for them and many felt VERY strongly that this was the only choice. For a feel of that you might want to check out this old (2009) and VERY long (15 screens) thread discussing insulation on metal boats on the Boat Design forum and specifically discussing “alternatives to foam”. It was a very “lively” discussion along the way but you will read comments by several professional boat builders stating the same thing that in their experience glued on EPDM is the only choice for them and I’ve found it to be the defacto standard now.
EPDM’s challenges or cons are that it takes a LOT of time to install well, it does not have as high an R value per same thickness of PU foam or XPS and it is heavier. However, I came to realise what all the big boat builders have which is that EPDM is the best overall “compromise” solution and I’m very happy with our decision to go with this.
Having said all this though, this like most all decisions in designing and building a boat is a very personal and subjective one where there is rarely a single “best” solution and so Christine and I focus on clearly articulating our priorities and use case scenarios and then using these to help guide us through each decision and enable us to come up with the Goldilocks choice that is just right, just for us.
Hope this helps and please let us know what you learn as you dig into this more.
– Wayne
My previous boat was all steel and had been built with a minimum of 100mm/4″ of professionally sprayed on PU foam so I have over 10 years experience being a full time liveaboard on that boat to help guide me. I often refered to the boat as “a floating thermos bottle” because it was SO well insulated and over the years it taught me of the big picture overall value of a super well insulated boat. However it also taught me equally as well about the problems with spray on insulation the most notable of which were that there were several areas where it had been very difficult to get the foam into or see what you were doing and sure enough these areas allowed moist air to get in there and eventually rusted through the steel hull plates. In most cases it took 12+ years to do so but this still created a tremendous amount of work to then have to cut out these rusted sections and weld in new ones. AND the job prior to that was digging all the surrounding foam out before you started in with cutting torches, plasma guns or grinding wheels. As you can read in that link above these are some of the top reasons why boat builders have largely moved away from the use of spray in place foams and gone with glued on EPDM.
Two of the largest brands for EPDM foam are AeroFlex and ArmaCell so a search on those terms and their sites will provide you with good information on their tech specs and properties.
Hi Wayne,
Thanks for your reply with a thorough description of the tradeoffs between EPDM and Boréal’s Cork/XPS system. I’ll definitely check out the links you provided for further research.
I noticed in another post that there were areas where you had to remove some insulation to accommodate the installation of mounting tabs for the workbench. From the photos it appears that while the contact adhesive is very tenacious it is still perhaps easier to modify than sprayed-in foam, and easier to clean up, so I will count that as another advantage.
BTW, my compliments on the overall design of the workshop area! It will no doubt make any maintenance task a little easier and more enjoyable, being able to work in such a spacious and well equipped compartment. Overall I would guess that it will also contribute to keeping maintenance costs down, enabling lots of DIY work as well as enabling any professionals to do their work more quickly and efficiently compared to a cramped space.
One last question regarding insulation: Did you find it necessary to provide a thermal break for the framing-to-workbench attachment points?
Good eyes Scott to spot that we have already done some impromptu “testing” of the adhesion of the EPDM foam insulation. It is difficult to be able to have all the welding done before we started to install the insulation and so you will see more examples where we have had to remove some of the foam to install more items in the hull such as the Fuel Fill & Vent boxes that I mentioned in last week’s post. Having owned and maintained our previous 52’ steel sailboat that had all spray in place foam, I can certainly attest to your observation that working with this EPDM is a joy by comparison.
Equally astute an observation about the benefits of having lots of room for installing systems and equipment. Some of that will accrue to me when I have to maintain all this and while difficult to quantify your point about having lots of space for others to install equipment onboard is a very big time and expense saver. And if you think the Workshop areas have lots of space, which they do, just wait till you see how much we have down in the cavernous Basement area under the whole SuperSalon floor! Once they get this area all insulated it will soon be home to a lot of equipment such as all our inverters, chargers, battery banks, pumps, fridge/freezer compressors, black water tanks and black boxes for all the navigation and monitoring equipment. While I did become quite skilled at my Houdini imitations as I contorted myself around and into some of the most awkward spaces imaginable on previous boats, I sure won’t miss letting that skill set go and enjoy being able to work on everything in comfortable positions with lots of space all around each piece of equipment for easy access, wiring, plumbing, and installation. I specifically designed the height in the Basement with this in mind for example to be 1.2 meters which is just right for me have ample headroom when I’m sitting or kneeling down there. For my aging back this is ideal and better than full standing headroom when I’m spending extended times in front of wiring cabinets or plumbing manifolds and the like. We haven’t really gotten started with the installation of the systems and equipment yet but already several of my fellow Team Möbius members here have commented on how much they like such attention to detail and how they are looking forward to doing the installations, wiring, plumbing, etc. in such roomy and easily accessed areas.
And yes we pay close attention to ensuring that we have no thermal bridges from the outside in and will use a variety of different materials to do this in different spots. Sometimes we will glue plastic (non absorbent) pads to the aluminium surfaces to create a thermal break where we have to attach things like cabinets, panels, etc. and in places like the workbench brackets we are using a very hard, thin and flexible material that is actually made of highly compressed EPDM. I will highlight these as we get to installing them in future posts.
Thanks for the comments and questions Scott, I learn and benefit from them so please add more as they pop up for you.
-Wayne