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How to Recaulk Seams

“I’d rather burn my boat to the waterline before I recaulk seams again,” a boat owner said to our Sales Manager at a recent boat show.

Then the boat owner laughed and said, “Of course, my family and I love the Hylas 54 too much to do this. But I sure did have some frustrations, largely my fault. It was my first recaulking job, and it was a big one with nearly one mile of seams.”


Aged teak deck

At TDS, we understand that it’s a big job. An aging teak deck can have proud caulking. Scuffing a foot on the deck could loosen the caulk. Or tugging on the caulking will easily pull it up. Additionally, if caulk has separated from the teak planking, it will eventually loosen if not repaired. These gaps will trap water and potentially cause damage.


We have perfected the art of caulking and want to share advice to prevent frustrations like those of the owner at the boat show. Here, we provide some time-tested tips, and if you call us, we will walk you through the process. We want your re-seaming project to be a success.


SIS 440 Caulking, a proprietary formulation, expands and contracts with boat movement and temperature changes. Caulk is designed to do this.


Teak naturally wears 0.25 to 0.5 mm/year, which will cause the caulking to become “proud.” So, it is essential to watch the deck as it ages and to perform a light sanding for periodic maintenance. This sanding will remove the proud caulk and keep the teak surface smooth. A smooth teak surface prevents trapping dirt.



BEFORE STARTING TO RECAULK SEAMS TAKE THESE NECESSARY STEPS


1) DETERMINE THE DEPTH OF THE SEAM

Seams should have a depth of 5/16 to 1/2” (8-12 mm)* for recaulking to be successful (and cost-effective). Do not fill shallow seams because there could be adhesion problems.



*Seams sizes could vary with larger and thicker planks.


Seam is too shallow for re-caulking

2) CHOOSE THE BEST LOCATION FOR TO RECAULK SEAMS

Always work under a cover. Ideally indoors for protection from rain or snow. Indoor temperature control will enhance caulk cure time. Ideally, the temperature should be 40-90°F or 5-33°C. If unable to work under a cover, only open as much seam as can be cleaned and recaulked on the same day.


3) SAND THE DECK

Before beginning to recaulk seams, a light sanding of the deck creates a smooth surface so that caulking does not fill any ridges in the teak. This pre-sanding will make the final sanding (after re-caulking) much easier, saving time.


4) REMOVE HARDWARE

Since sanding is required before and after recaulking, the hardware will rest on proud teak if it is not removed.


5) READ THE APPLICATION INSTRUCTIONS ON THE CAULK PACKAGING

Instructions are carefully written to help users (with SIS 440).


REMOVING OLD CAULKING

Remove ALL caulk to prepare clean seams of fresh wood for new caulk. For small jobs, remove caulk with a razor and reefing hook.


For large jobs, electric tools are better. A Fein tool with a teak caulk removal blade works well. For experienced users, a saw or router can be used.

Regardless of the tool, work carefully to not gouge the edges of the seams. Then, the seams MUST be sanded, vacuumed, and cleaned with acetone. Fresh, clean wood ensures optimal adhesion.


BOND BREAKER TAPE IN SEAMS

Place bond breaker tape at the bottom of the seam. The tape prevents an adhesive bond of the caulking to the bottom of the seam, allowing movement during caulk expansion and contraction.


FILLING THE SEAMS

The temperature must be at least 40°F (5°C) when caulking. Fill seams with a manual gun, electric gun, or pneumatic gun. Regardless of the gun type, cartridge tip preparation is the same.


Cut the tip of the cartridge at an angle. Then insert a screwdriver to puncture the foil lining. After completing this, squeeze the tip to flatten it. This will help to align the tip with the seam. NOTE: Fully open the tip and foil, or caulk may push out from the back of the cartridge.


Begin application and ensure caulking goes to the bottom of the seam, allowing it to flow upward until crowning above the top of the seam. Smoothly pull the gun along the seam toward the applicator. Avoid starts and stops or changes in direction that may entrap air.

If using a pneumatic caulk gun, do not exceed 80 psi to prevent overriding the plunger and injection air into the caulk.



Immediately after applying the caulking, draw a flexible putty knife over the seam. Apply enough pressure to make sure caulk fills to the bottom of the seam, and then crowns to allow for slight settling. Make sure the seams have no entrapped air after application. Do not disturb the caulking until fully cured.


Apply pressure to fill seam. Be sure that caulking crowns.

Masking the teak before caulking may be done. Place tape 1 mm from the edge of the seam. Note: It will require more pressure to fill the seam with the putty knife with a masked edge.

CURING

Cure time is a function of the cross-sectional dimension of the seam and ambient temperature and humidity. Cold or very dry air will increase the cure time. Caulking cures from the top down at a rate of about 1-2 mm/day with a maximum rate of 3mm/day. Allow at least 48 hours. White and gray will take longer, so please read about these special considerations at https://teakdecking.com/caulk/

SANDING AND FINISHING

Sand using 80-100 grit sandpaper with a soft pad on a grinder. Do not use orbital and belts sanders because they may “dig” into the teak. A Fein tool with a sanding pad is good for the corners. Hand-sanding is required for details that cannot be reached with power tools. Rich brown teak and razor-sharp seams appear as the caulking is sanded away.



If there are gaps, bubbles, or under-filled seams, it is due to improper caulking. The seams were not filled properly or did not cure adequately.


This deck was not sanded before recaulking, making it difficult to sand off the caulking

We want your project to be successful. To recaulk seams, follow these recommended guidelines and read our free 16-page Caulking Guidebook: Teakdecking.com/caulk. Or Call us if you have questions and we will walk you through the process.


Read more articles:

How to Inspect Teak Deck Caulking and Seams

Application Techniques for Gray and White Caulking

What is the Caulk Yield for Teak Deck Caulking

CONTACT TEAKDECKING SYSTEMS

941-756-0600

products@teakdecking.com

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February 20, 2025
The yachting community has long held the belief that viable teak must come from very old, natural forests, with much of the industry still adhering to the notion that teak must be 100 years old. Despite the environmental and humanitarian controversy surrounding teak, many owners worldwide continue to request it. This guide explores the different wood materials currently available , helping industry stakeholders and owners to make informed decisions about the best option for their deck . The information is divided into two sections titled "Wood we work with" and "Wood we do not work with." It is intended solely for educational purposes, providing detailed information on the characteristics, merits and concerns of each type. As a leading deck builder and installer, TDS remains completely impartial with no vested interest in any of the products discussed in this guide. MYANMAR TEAK The importation of Myanmar teak into Europe has been illegal since 2013 under the European Union Timber Regulation (EUTR), which aims to prevent the sale of illegally harvested timber. In 2021, additional sanctions were introduced that further restricted its availability, extending the ban to the USA as part of broader efforts to curb deforestation and human rights violations linked to the Myanmar timber trade. That same year, the Council of the European Union imposed targeted sanctions on Myanmar’s military regime, specifically restricting its ability to export timber that serve as key revenue sources for the junta. Despite these restrictions, Myanmar teak continues to be traded in countries that do not enforce such sanctions, including India, China, the UAE, Turkey, and Australia. Note, these restrictions may change at anytime. WOOD WE WORK WITH PLANTATION TEAK Characteristics Less dense than old-growth, natural teak. Younger trees aged between 30-50 years. Is resistant to insects and rot. Merits Despite the shorter and narrower planks, we can still get 20mm thickness and planks up to 2.2m. By using scarf joints or finger joints we can create 4m battens that are glued together. Shorter planks also reduce the purchase price. A guarantee that the forest is managed in an environmentally responsible and sustainable manner, including practices such as replanting trees, protecting biodiversity, and minimizing environmental impact. Verifies that the teak is sourced from legal and well-managed forests, reducing the risk of illegal logging, and complying with international law. The teak undergoes rigorous quality control measures, ensuring it meets certain standards for durability, strength, and appearance. Social Responsibility is at the heart of the activity, including fair labor practices and community engagement, supporting local communities, and ensuring workers' rights are respected. Plantations are managed with long-term sustainability in mind, ensuring a reliable and consistent supply of teak. Well-managed plantations, act as carbon sinks, helping to mitigate climate change by absorbing and storing carbon dioxide from the atmosphere. If properly maintained a deck will last 15-20 years. Concerns Some plantation teak is harvested too early for quality yacht decking. Less growth rings, resulting in lower grain quality. Less density that can give rise to warping and bowing. Pin knots are a consequence from pruning lower branches. Plantation managers, governments are reluctant to direct resources towards certification schemes. Where to source it? India, Indonesia, Tanzania, Benin, Brazil, Thailand, Sri Lanka, Costa Rica, Trinidad Note: there are other countries with younger 15-20 year teak. CERTIFIED GREEN TEAK Characteristics Uses parts of 30-40 year-old trees that would normally be rejected due to knots and imperfections. Sliced into thin veneers and glued together, to form a modified material with superior strength. Lengths up to 4m and allows large widths due to laminations Aesthetically attractive, with a plank like finish. Excellent durability as the laminating process enhances its stability and dimensional integrity. Is resistant to insects and rot. Merits The veneers are similar to the vertical grain of natural teak. Yield about 85% of the log vs 2-15% of log for Vertical Grain Renowned for its hardness, strength, and durability. A test panel currently on a yacht, had a 10kg scaffolding pole dropped onto it, causing only a 2mm dent. Limited susceptibility to cracking and warping, when cut and dried correctly. Non-skid surfaces. Extra insulation in hot and cold climates. A well-maintained deck should last 15-20 years. Concerns It may have variations in color and texture due to differences in the wood grain and moisture content of individual layers. Ensuring the quality and integrity of the bonding process is crucial, as poorly bonded laminations can lead to delamination, weakness, and structural issues over time. While lamination can improve the stability of green teak, the overall durability and longevity of green laminated teak may still be inferior to properly seasoned teak. It still requires careful moisture management to prevent swelling, shrinkage, or damage over time, especially in environments with fluctuating humidity levels. In some cases, the adhesives used in the lamination process contain chemicals. Where to source it? Thailand THERMALLY MODIFIED WOODS ACCOYA Characteristics Certified sustainable fast-growing softwood “Radiata Pine” is its base material. The wood is acetylated using acetic anhydride and water. It makes the wood virtually unable to absorb water, expand and rot. Merits Extremely durable, they guarantee it will last 50 years for use above ground and 25 years for use below ground. The wood can be reused, recycled, or burned as biomass (fuel). A great option for certain vessels such as catamarans. Very low maintenance. Concerns The color is different to what the industry “expects”. Its not as hard as teak, as it still has a lot of softwood. Where to source it? The Radiata Pine is harvested in New Zealand and shipped to the Netherlands for the modification process. TMT MARINE LIGHT Characteristics Significantly cooler than teak. Much lighter than teak. Similar abrasion resistance as natural teak. Merits Very dimensionally stable. Resistant to shrinking and swelling due to humidity, temperature, and moisture content. Resistant to decay and insects. Large logs that produce long, wide boards with tight, vertical grain. Can be used for interior applications, accepts stains and finishes. Fast-growing, sustainable species. Durable, slip resistant surface that is excellent for marine conditions. Concerns Much lighter in color, almost white before weathering. Soft wood that needs to be carefully sanded to remove scratch marks. Limited availability. Prone to splitting, chipping, and splintering requiring high quality tools and sharp blades when working. Where to source it? Western United States and Canada. WOOD WE DON'T WORK WITH THERMALLY MODIFIED WOODS AMERICAN HARD MAPLE Characteristics Specifically created for the marine industry Thermally modified by a controlled pyrolysis process of the wood being heated to (> 180 °C) in an oxygen free atmosphere. This process changes to the chemical structures of wood's cell wall components; lignin, cellulose and hemicellulose which increases its durability. Merits No chemicals are used during the modification process. It looks like teak. It weathers to grey in the same way as teak. Claims a zero-carbon footprint. Concerns Cracking. The color of thermally modified maple can vary depending on the specific treatment process and wood source, which may affect its suitability for certain design schemes. Where to source it? USA. TESUMO Characteristics Fast-growing African tree that matures in 50 years. Sourced from certified managed forests. Modified using heat, resin infusion and drying. Merits Developed as part of a research project conducted by Lürssen Shipyard and the German University of Göttingen.Can be disposed of by burning. Tested for years on land and at sea. Similar appearance, dimensional stability and rot resistance as teak. Concerns Limited amounts available. Where to source it? Germany. IROKO Characteristics African hardwood native to West Africa. Is resistant to rot and termites. Long, wide boards. Merits Similar color to teak. Economically priced. Concerns Extremely hard wood to work with: produces an enormous amount of fume and dust, prone to splintering and blunts work tools. Susceptible to cracking. Requires a lot of maintenance. A deck will last 5-6 years. Where to source it? West Africa. LEGAL DISCLAIMER This document is for informational purposes only and does not constitute professional, legal, or environmental advice. The information provided herein is based on publicly available industry knowledge at the time of publication and is subject to change due to evolving regulations, market conditions, and environmental considerations. TDS does not endorse, recommend, or assume responsibility for the sourcing, legality, sustainability, or quality of any wood materials mentioned in this guide. This guide is provided solely for educational purposes, with no commercial interest in promoting or favoring any specific wood type, supplier, or industry practice. The inclusion or omission of any material does not imply endorsement or disapproval of any specific supplier, manufacturer, or distributor. All information is presented without any warranty, express or implied, regarding accuracy, reliability, or completeness. TDS expressly disclaims any liability for direct, indirect, incidental, or consequential damages arising from reliance on the content of this guide. Readers are encouraged to conduct independent research, consult industry professionals, and verify compliance with applicable laws and regulations before making any decisions related to wood procurement or usage. By using this guide, readers acknowledge and agree that TDS is not responsible for any business decisions, financial outcomes, or disputes between suppliers, manufacturers, or buyers. Any reference to specific wood sources or countries is purely informational and does not imply any partnership, business relationship, or endorsement.
February 19, 2025
We are thrilled to announce our partnership with Matt Graham and Total Decking to expand our presence in key U.S. markets. This collaboration is focused on delivering high-quality decks to boats in the 20-150 foot range, in Maine, Newport/Southern New England, and Chesapeake. Matt Graham, owner of Total Decking, brings a wealth of experience to the partnership. With a background in both business and marine craftsmanship, Matt has worked in boatyards since the age of 14, later serving as Chief Operating Officer of Lyman-Morse Boatbuilding for eight years. A dedicated offshore sailor and skilled carpenter, Matt's experience ensures that Total Decking delivers top-tier deck installations tailored to TDS standards. Total Decking was originally founded by Larry Murray in 1987 to serve TDS clients in the New England market. Over the years, the company has completed hundreds of successful installations across a wide range of vessels from classic cruising yachts to modern race boats. Under Matt’s leadership, Total Decking has expanded its territory to Southern New England and the Chesapeake Bay region, recognizing strong growth opportunities in the area where he grew up. Partnering with TDS allows us to provide even better service and extend our reach into key maritime hubs," said Matt . "With our dedicated team, we aim to be the most efficient and highest-quality solution for TDS installations. We understand the challenges boat owners and builders face when it comes to decking, and we are committed to offering precision, durability, and the highest level of craftsmanship. Our focus is on long-term customer satisfaction, and we are excited to bring these high-quality decks to a wider market ." Total Decking currently operates with a five-person team, each member deeply rooted in the marine industry . Alongside Matt, key team members include Phil Huening, a 15-year veteran of TDS installations; Miles Mancini, a naval architect with a degree from Southampton University, Sam Lloyd, a seasoned marine professional and avid racer, and Rory Rowe, a skilled craftsman with a background in high end tiny home construction. Richard Strauss, CEO of TDS commented “We are excited to join forces with Matt Graham and Total Decking. Their expertise, and dedication, align perfectly with our mission to provide the best decking solutions in the industry. This collaboration will strengthen our ability to serve customers in these key markets and uphold the high standards TDS is known globally for. ”
January 30, 2025
When it comes to selecting a company for your new deck, transparency and trust are essential. While we at Teakdecking Systems believe in the superior quality and craftsmanship of our decks, we also understand that we are not the cheapest option. While cost is an important factor, it’s equally crucial to consider the long-term value and durability of your investment. If you decide not to entrust us with your new deck, we strongly encourage you to do your due diligence and ask the right questions before committing. Our top priority is ensuring you make an informed decision, no matter whom you choose to work with. A new deck is a significant investment and balancing cost with quality and durability is key to avoiding costly mistakes down the line. To help you navigate this process, here are six crucial considerations to guide your decision-making process: 1. Research the Company’s Reputation The first step in evaluating a decking company is to research its reputation. A quick online search can provide valuable insights into their track record through reviews, ratings, and testimonials from fellow yacht owners. Social media groups, forums, and word-of-mouth recommendations are also great sources of information. Pay close attention to any recurring themes in feedback—positive or negative—as they often reveal the company’s strengths or potential red flags. 2. Understand the Quality of the Teak Not all teak is created equal. High-quality, seasoned old-growth teak is far superior to plantation or fast-growing teak. Old-growth teak has tighter growth rings, which make it denser, less permeable, and significantly more durable. Plantation teak, while more readily available, lacks these qualities and may not hold up as well in the long term. Knowing what kind of material you’re putting on your yacht will ensure you make a well-informed investment. 3. Verify the Legality and Availability of Materials Legal sourcing of teak is not only an ethical concern but also impacts project timelines. Some companies may not stock the teak they use, instead purchasing it only when an order is placed. This could lead to delays, particularly if the company encounters sourcing challenges. Ensure the company you choose has legal teak readily available in their possession. This not only guarantees compliance with international laws but also reduces the likelihood of unforeseen delays in your project. 4. Compare Decking Materials While teak is a popular choice for yacht decking, there are alternatives like EVA foam, PVC, Polyurethane, and cork that you may consider. Each material has its own pros and cons in terms of cost, durability, and appearance. For instance, EVA foam is lightweight and budget-friendly but lacks the longevity of teak, while PVC and Polyurethane offer varying levels of durability and cost-effectiveness. Carefully evaluate these options and discuss them with the company to determine the best fit for your needs and budget. 5. Review Past Projects and Current Workloa d A company’s previous work speaks volumes about its capabilities and standards. Request to see examples of past projects, ideally ones similar to your vessel, to gauge their expertise. Additionally, inquire about their current workload. If a company is overbooked, your project could face delays, leaving your boat out of commission longer than expected. Asking for a clear manufacturing and installation timeline can help you set realistic expectations and plan accordingly. 6. Select a Reputable Yard Where the work is performed is just as important as who performs it. Opt for a reputable yard that has experience handling yacht projects. A good yard can coordinate with subcontractors, enabling multiple tasks to be completed simultaneously, which saves time and ensures a smoother process overall. Effective project management is crucial in these situations, so ensure the yard has a proven track record of handling yacht renovations. 7. Warranty & Service When evaluating decking companies, it is important to check if they offer a warranty and ask detailed questions about its coverage. Does it cover both materials and installation? What is the duration, and are there any conditions or exclusions? Clarify where warranty work will be carried out and any associated costs, such as transport, subsistence, lodging, and logistics required for repairs. 8. Global Service For yacht owners constantly on the move, choosing a company with reliable global support is essential. Evaluate the company's operational reach and its ability to respond and travel to your vessel if needed. For total peace of mind, TDS decks are covered by a worldwide warranty, ensuring customers receive top-tier service and support wherever they are. Final Thoughts Choosing the right company for your yacht’s decking is a decision that shouldn’t be taken lightly. Transparency, reputation, and quality should be your top priorities when evaluating potential companies. By asking the right questions and thoroughly researching your options, you avoid costly mistakes and ensure your deck meets your expectations in both quality and longevity. While cost is always a factor, remember that value is about more than just the upfront price, it’s about the durability, craftsmanship, and long-term performance of your deck. A well-informed decision will not only protect your investment but also enhance your enjoyment of your yacht for years to come.
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