Harder than Steel
British/Mexican shipwright Pablo Cruz Gilmour dives into his experiences building Ceiba’s frames, working with a variety of local hardwoods and how they are sourced. Technical and informal, this post is full of all the hands-on information woodworkers are so eager to know.
I’ve spent 6 months on the framing stage. Last Friday, Frame 17 went up which was also the 17th frame I’ve built since I’ve been here and the 37th frame raised overall, bringing us to 66% completion, a cool 2/3rds of the framing process. It took a little longer in the beginning, ironing out the creases in our process, but we are now proudly steady rolling at a one frame per week pace, with the Guapinol frames taking a day or two longer. Last week 3 frames (2 midships, 1 half frame) were raised in 6 working days, a new record.
Here we see Nico fairing. Note the color change in the freshly cut wood.
Every fourth frame is Guapinol, commonly known as Jatoba (Hymenaea courbaril), in high stress areas of the ship including the entire bow and stern assemblies, deadwoods, stem and fore and aft half frames/cant frames and frames where the mast steps land. Though the framing is primarily Spanish Cedar, Cedro as we call it (Cedrela odorata) fastened together with bolts and trunnels or “tree-nails” (usually made of Tamarindo Del Monte (Dialium guianense) or Guachipelín (Diphysa americana). In this post I’ll be talking about my experiences working with these four beautiful, tropical hardwoods.
Guapinol / Jatoba (Hymenaea courbaril)
Every time we get to the next Guapinol frame, it’s almost as if the entire yard lets out a collective groan. The frames are composed of several large pieces of timber, sawed to the required shape and fastened together to form the frame. This stuff is testing to work, its sheer weight and hardness, coarse interlocked grain and occasional calcium deposits pose some serious challenges. With a Janka hardness of 2,690 lbf (11,950 N) almost double that of White Oak (1,360 lbf or 6,000 N) and an average dried weight of 57 lbs/ft3 (910 kg/m3) this wood is tough. It sinks in water. We drill it with slow speed and lubricant to prevent overheating, as you would with steel. During the last frame assembly, it took more than a day to drill the fastening holes. Many faithful industrial drill motors have paid the ultimate sacrifice boring the timber during construction. With its beautiful, rich, red brown colour with dark streaks, Guapinol is certainly a handsome material. Blowing out bright orangey yellow sawdust when the wood is first cut then darkening to a light brown upon exposure to sunlight. Though the heartwood is very durable to rot resistance, the light pale-yellow sapwood is not and must be dealt with to put a stop to rot and friends of rot getting into the ship.
Everyone feels the weight as the wood passes through so many hands to get to its final resting place, standing tall on the keel. From our team of experienced sawyers ripping the great logs with chainsaws on the Alaskan mill, to the team flattening and planing the surfaces, ready for lay out. The wood is so hard and so heavy that moving it smoothly and accurately across the bed of the Ship saw (an enormous antique bandsaw, where the table stays flat and the entire thing tilts to cut changing angles) is unfeasible, even with a large team. A special chainsaw jig that slides across the surface of the timber has been made that is able to cut the rolling bevels. Sometimes it’s just easier to move the saw to the wood, rather than the wood to the saw. Not to mention the chain saw blades are far easier to sharpen, more so than our bespoke sawmill blades, made for the shipsaw which is out of production since the early 1900s.
Chainsaw Jig
Shipsaw
Once sawn to shape, the lumber must make its way up onto the framing stage. Thank God for blessing us with tractors is all I can say. We didn’t always have it this easy, but it's amazing what you can move by hand with a few big bars, sawhorses and some basic knowledge of physics. Once the pieces get on the stage, for me the real work begins. We work to a high standard here at the yard, and pride in craftsmanship means every frame must be of this quality. However long you think a task will take, if you are working with Guapinol, double it, if the Guapinol is not working with you, triple it. It’ll be great when it’s done, we say.
The wood often arrives with defects, imperfections, inclusions, cracks, voids, rot, the lot! Nothing structural, but all things that must be addressed before it can go in the boat. This means that a large percentage of futtocks (pieces of the frame from the keel up) will have to be repaired with a ‘Dutchman’ or Graving piece, and sometimes these new pieces of healthy wood can be pretty big. Digging this deep into a wood that feels like it's actively blunting your tools is challenging work. A lot of the final touches are done by hand, so your tools have to be sharp, all the time. This means honing your edge several times an hour. Inconvenient, but necessary. Guapinol also has an exceptional amount of tannins, much like oak. It stains my entire hands a deep purple and chips flying off the chainsaw turn my skin a dusty black, making me look like a coal miner. After much trial and error, I have found that the best way to remove these stains is with fresh lime juice, unfortunately it is also the best way to find out just how many tiny cuts you have in your hands.
Ceiba’s frames are double sawn, called double because the material is doubled in thickness by the lapping of joints. Our 6” (15cm) wide frame pieces are practically 12” (30cm) sided measure. The largest floor timber (the lowest and largest piece of each frame, notched over the keel) so far was just shy of 4m (almost 13”), so you can get an idea of the size, scale and weight of these timbers. Believe me, the hauling teams raising the frame can really feel the difference as you hear both them and the blocks groan as the frame is hoisted into place.
Spanish Cedar (Cedrela odorata)
It’s always such a relief to go back to building a Cedro frame. This attractive, light pinkish brown wood works like butter! Spanish Cedar is durable regarding decay resistance and termite attack (important in this part of the world!) and has excellent weathering characteristics, slightly greying with time. Though not a true cedar, Cedro is more closely related to the true Mahoganies, being in the Meliaceae family. The wood has a pleasant and distinctive odor like the true cedars, but an extremely bitter taste when it gets in your mouth. I have found being covered in fine Cedar dust from the Beam saw to be an effective natural mosquito repellent. With an average dried weight of just 29 lbs/ft3 (470 kg/m3) it's almost half the weight of Guapinol and more than four times softer (Janka hardness of 600 lbf (2,670 N) a similar hardness to Douglas Fir but a very different grain, generally straight and slightly interlocked and far less pronounced. This stuff is a dream to work. It planes and cuts easily and sharp tools leave a smooth glassy surface.
Tamarindo de Monte (Dialium guianense)
The frames are bolted together and fastened with 1 ⅛” (28mm) trunnels made from Tamarindo or Guachipelín, with Tamarindo also being used for the keel. One of the most abundant and useful timber trees of central America, it is commonly harvested from the wild and our lumber for the keel came from six Tamarindo trees that came down during Hurricane Otto in November 2016, the first hurricane to hit Costa Rica since records began. An attractive, light purply brown wood, deepening to a uniform reddish brown upon prolonged light exposure, this is another one of those timbers that makes you shake your head when you realize how hard and heavy it is. Comparable to Purpleheart this wood was an excellent choice for the keel. Strong in shear and compression, with good tensional strength and rot resistance, as well as making the most of windfallen trees, it was an easy decision. Four logs were milled into big beam timbers and scarfed together at tactical locations, with special attention taken to avoid too many fastenings going through the keel in any one place. Tamarindo does not float and has Janka hardness of 2,690 lbf (11,950 N) and dried weight of 53 lbs/ft3 (850 kg/m3) compared to Purpleheart (Janka hardness 2,520 lbf (11,190 N) and average dried weight of 56 lbs/ft3 (905 kg/m3).
Filled with silicates (fine sand), the Tamarindo has a severe blunting effect on all edge tools. The wood is also so incredibly hard, that with the resources we have available, it can only really be cut when its green. There is an enormous amount of tension in this wood, and when cutting on the Alaskan mill it is not uncommon to hear a huge bang and a crack as the wood splits, sometimes binding or even throwing the saw. Not fun. The beginning of the cut would have to be chained down to stop it peeling upwards as the cut progresses, and the big Stihl 780 chains would have to be sharpened after every single refuel, multiple times per cut. On top of this we have found the wood to be relatively unstable with some movement since the keel was laid in late 2018, nothing unaccounted for but still another job added onto the endless list.
The offcuts always find a good use around here, nothing is wasted. Tamarindo makes for an exceptional mallet head, capable of pounding in ⅞” (22mm) steel bolts, week in, week out, for months on end, barely marring the surface. In my working life I have made many wooden mallets and Tamarindo is by far my favorite material for the head. Except while you’re making it. You can actually hear the pitch of your chisel change from a sharp whack to a dull thud in a matter of minutes as the edge rapidly becomes blunt. But as I always say, it’ll be great when it's done. The Guapinol does not fare so well for Mallets, it is hard to the point of being brittle with many a Guapinol mallet head splitting and ending up on the burn pile.
Guachipelín (Diphysa americana)
As time has gone on and the Tamarindo has started to run out, we have made a rational choice and decided to switch timbers for a more suitable (and workable) wood. Enter Guachipelín, a gorgeous, sweet-smelling, honey coloured wood. Used primarily for trunnels, it has a similar grain to Black Locust, one of the most durable woods in North America, with a long Maritime history. The bright yellow wood is springy and flexible, as well as being hard and highly resistant to rot. Though it can be difficult to work, it’s a perfect alternative for trunnels, as well as replacing that hammer handle the apprentice broke. Guachipelín also has a high tannin content, like that of White Oak, so once again your hands get stained black. The trees tend to be smaller and the grain is not always as straight as it could be, leading to grain run out in some of the trunnels and the occasional split, so careful observation of the grain and must be taken prior to driving them in with the occasional help from a pair of locking pliers.
Floor piece and Trunnels (tree nails)
So where does all this wood come from? Our wood for the hull is 100% sourced here in Costa Rica. A country that has implemented one of the most advanced environmental protection systems in the world, through the development of a booming ecotourism industry and progressive legislation that has linked conservation and reforestation to economic growth and incentives. The country now protects 27% of its land in National Parks, wildlife refuges and over 100 private reserves, and has become the first tropical country to radically reverse the process of deforestation, with forest cover increasing from just 21% in 1990 to 52% in 2005 (Manuel Rodriguez, 2005). Costa Rica is a REDD+ country, referring to "reducing emissions from deforestation and forest degradation in developing countries, and the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks in developing countries." (REDD, 2020) Our main wood-sourcing contact is Hernan, of Guacimal. Hernan not only finds the appropriate trees for us, but also secures the environmental permit for each individual tree to remove it from the land. Many of the trees were taken down naturally by the wind, making them both locally and sustainably sourced. A recent, large batch of Spanish cedar we acquired was part of a living fence on the side of the road, that the local municipality decided had to be cut down for the road to be widened. The stock for our Guapinol stem and bow assembly was recovered from a nearby landslide, quite common on the mountain roads in the rainy season. It is our aim to source all the lumber for our tallship 100% sustainably, using as many naturally windfallen trees as possible.
We are extremely grateful to be able to source all our spars (masts, topmasts, yards, booms, gaffs and the bowsprit) of environmentally and culturally responsible Sitka Spruce (Picea sitchensis) from Haida Gwaii. A first nation archipelago off the west coast of Canada, an area world renowned for its straight, clear timber for superior sailing ship masts. This will be the first timber sourced outside of Costa Rica, so we felt that it was important that it be the best quality possible, and that it hails from the highest moral and environmental standards.
Helping to build Ceiba has been one of the most challenging and rewarding experiences of my life. These past six months have flown by. It’s a special place out here in our jungle shipyard and it’s not for the faint of heart. I feel honored to work with such beautiful, vibrant, and diverse woods and honored to work with such a beautiful, vibrant and diverse crew of incredibly skilled and talented individuals from across the globe. Nothing is possible without working together and neither is the sustainable future of our planet. I’ve extended my time here because, for me, this project is the future. It’s something I truly believe in and stand behind. It can be a moral conflict being a passionate woodworker and caring for the future of our planet and our forests, but with a project like Ceiba, it’s possible.
SOURCES
Carlos Manuel Rodríguez (2005). Conservation and Development: Lessons from Costa Rica. Retrieved from https://www.wilsoncenter.org/
The Wood Database: https://www.wood-database.com/
One World UK: https://www.oneworld.org/
REDD+ Costa Rica: https://www.reddcr.go.cr/
SAILCARGO INC.: https://www.sailcargo.org/
