Apr 9, 2020

Wetting Fibreglasswetting out fibreglass using unthickened epoxy and a squeegee

In Parts 1 and 2 we discussed fiberglass and gelcoat. This time, we’ll explore the ways that epoxy can be used aboard.

In most marine chandleries, a section of shelving is often dedicated to paints, sealants and epoxies. Brand names like West System, System Three, MAS, East System (and others). In my opinion, personal preference and price are the determining factors between the brands – though, I recommend using all the products from one line in each application, because they are formulated specifically to be used together.

Each line or brand will have similar products available (West System popularized a numbering system which can be very convenient to ensure that the right product is used for the right application):

Epoxy Resin – This is the base that other products are added to, in order to achieve the desired results. Epoxy resins tend to be thicker than polyester resins, and are more versatile in a number of ways

Epoxyepoxy with thickening agents to make it peanut-butter consistency

Hardener – this is mixed with the resin at a pre-determined ratio. In the early days of epoxy usage, resin and hardener volume had to be weighed or metered out. Today, manufacturers make is much more simple by producing metered pumps that fit into the product containers. The ratio of resin to hardener may be 2:1 (meaning that twice as much resin is used as hardener), but by using a metered pump (almost like a hand-soap dispenser), the user simply has to mix the same number of ‘pumps’ together. Therefore, 1 pump of Resin is mixed with 1 pump of hardener.

Hardeners are available in a standard, and also in ‘slow’ and ‘fast’ formulations. They work by initiating a chemical reaction with the resin. The reaction starts the moment that the two are mixed, so mixing and applying quickly can become important. Slowing down the reaction can be done by choosing a ‘slow’ hardener, and also keeping the mixing pot and work area cool and mixed thoroughly. Keeping warm hands away from the mixing pot, and giving the mixture a stir regularly helps. Similarly, ambient temperatures, as well as using a heat gun can speed up the reaction significantly.

Polyester resins and gelcoats are dependent on the quantity of MEKP hardener added (to a certain point), and can take 10+ hours (sometimes days) to fully cure. Epoxy mixtures shouldn’t be adjusted – the ratio needs to be kept to manufacturer specifications – but the type of hardener used and control of temperature can adjust the working time of the mixed epoxy.

With resin and hardener mixed, the workings for epoxy are present, but further products should be added based on the application that the epoxy is being prepared for.

Thickened Epoxythickened epoxy brings formed into a fillet to strengthen the joint

Epoxy can be used for a number of applications aboard:

Laying up Fibreglass – Epoxy can be used the same way that polyester resins can to infuse fiberglass cloth, roving and/or mat to fiberglass hulls, decks or components
Bonding/Adhesive – by adding a strengthening filler, epoxy can be used to bond objects, including: scarf joints in wood, laminating wooden parts into curved shapes, adhering wood or fiberglass eliminating the need for hardware.

Strengthening – epoxy can be thickened with strengthening fillers and spread along joint edges in a fillet, increasing the overall strength of the joint.

Filling/Fairing – a filling/fairing compound can be added to epoxy making it a peanut butter consistency, allowing it to be troweled into gaps, holes or damaged sections. Once cured, the fairing compound becomes easy to sand and smooth.

Metering PumpsSealing/coating – epoxy (with no fillers) can be painted or rolled over surfaces (particularly bare wood or end grain) to protect areas from rot or damage. The results can be an attractive glossy finish.

Casting – epoxy can be poured into a mould, or infused into carbon fibre or Kevlar to make composite shapes and components. Epoxy maintains it’s volume as it cures, as opposed to polyester resins which shrink as they cure (polyester resins will often crack when poured into a mould).

metering pumps that allow the correct ratio of resin to hardener

There are a variety of pros and cons to epoxy – here are the most notable, when taken from a boat owner’s perspective:

 

Pros:                                                                                   Cons:

• Ease of use                                                                      - Can irritate skin and fumes are toxic
• Preformulated adhesives and fillers                                 - Short working time
• High availability                                                                - High cost
• Adheres to most boat components                                   - Doesn’t adhere to plastic
• Established brands with customer support                       - polyester resins don’t adhere to epoxies
• High degree of strength and durability                              - gives off heat when curing
• Numerous applications aboard

If you’re planning to make a first attempt with the use of resins or fiberglass, I would highly recommend using epoxy to start, as opposed to polyester resins – they’re quite forgiving, and manufacturers have the end-user in mind in the formulations, packaging and educational literature. There are many books available, along with manufacturers websites and video tutorials. Enjoy the journey!

Andrew McDonaldAndrew McDonald is the owner of Lakeside Marine Services – a boat repair/maintenance firm based in Toronto. Andrew has worked in the marine industry for 12 years and is a graduate of the Georgian College ‘Mechanical Techniques - Marine Engine Mechanic’ program.

Questions or comments for Andrew? Email him directly via: This email address is being protected from spambots. You need JavaScript enabled to view it.

Related Articles
Maintenance
  • 07 July 2020
  • By Ethan

Ask Andrew: Tune-ups

Many boats are now on the water after a COVID-imposed hiatus – and with a shortened ‘prep’ period, usually filled with antifouling, polishing, cleaning, engine check-overs and the installation of a new...

Boat Reviews

  • Prev
New at the end of 2019, the 58 Salon Express design features large windows to flood the living ...
No wonder this is one of Regal’s best-selling boats; the Regal 33 Express offers amazing ...
The newest member of Beneteau’s Gran Turismo line is the GT 36 and this yacht brings the style and ...
With a philosophy of quality and 'doing things right Ranger Tugs launches the all new R-25 at the ...
The new Beneteau Swift Trawler 41 renews the spirit of the practical seaworthy cruiser. The ...
The Canadian Yachting test crew last week had the opportunity to run the Bavaria S36 HT at St ...

CY Virtual Video Boat Tours

Virtual Boat ToursWe all love boats and nothing can break us up! So, what better way to spend our time than looking at interesting boats and going aboard in a virtual ride or tour. We have asked our friends at various dealers and manufacturers to help us assemble a one-stop online resource to experience some of the most interesting boats on the market today. Where the CY Team has done a review, we connect you to that expert viewpoint. Our Virtual Show will continue to grow so visit frequently and check it out. If you can’t go boating, you can almost experience the thrill via your screen. Not quite the same, but we hope you enjoy our fine tour collection.

 

Read more about the CY Virtual Boat Tours....................

AXOPAR 37 XC

 

Axopar 37 XCWhole new ball game…

 

Set aside your assumptions and expectations for a few minutes while we try to describe the new Axopar 37 XC that made its American debut at the 2020 Miami International Boat Show. This boat represents a whole new ball game in terms of design, performance, seakeeping and functionality. In fact, I’d say it takes a ‘clean sheet of paper’ approach to boating – it’s that different.

Read More about the Axopar 37 XC..................

Destinations

  • Prev
On May 19, the New York State Canal Corporation today announced an updated opening schedule for the ...
If you have four hours to enjoy a fine tour of one of Canada’s most interesting waterways (let’s ...
Boom & Batten Restaurant is suspended over the water adjacent to the Songhees Walkway and ...
Provincial Boat Havens are those special places to drop anchor in British Columbia’s West Coast and ...
NW Explorations, a Bellingham, Washington-based yacht charter, brokerage, and marine services ...

DolphinsBy the Canadian Yachting Editors


Canadians are blessed in many ways and especially when it comes to boating. We enjoy some the world’s most beautiful cruising waters and many places are as sheltered as they are scenic.

British Columbia and the Pacific North West plainly have the most breath-taking scenery with the combination of the majestic ocean views and the snow-capped mountains in the distance. It’s like no place on earth when you have a Killer Whale breach beside your little fishing boat.

Read more about Canadian Cruising...........

 

Lifestyle

  • Prev
This interesting shot is one you will remember. It comes to POTW from our pal, photographer and ...
Unknown to us at the time, the quest for VIA-MARA started in 1973 when I saved the back cover of a ...
You will find that many of the yachts travelling up and down the BC Coast have Sea Kayaks on board. ...
The Council of British Columbia Yacht Clubs with over 50 yacht club members has become the voice of ...
Classic boat restoration expert and wooden boat builder Stan Hunter recently sent us this great ...
In Mid June, a floatplane plunged into Constance Bay on the Ottawa River after two planes collide ...
Winter is a fun time for sailmakers in Canada. We grind through mountains of repairs and have an ...
The seasoned sailor mapped out an ambitious course around the world — aboard his 28-foot ...
Clean wake: A concept amongst cruising sailors that stresses the impact that individual behaviour ...
This line-up of Beneteaus can to us from our friends at RCR Yachts in NY State where they are ...

Marine Products

  • Prev
Stainless steel is an ideal metal to use on a boat, but it's not maintenance-free; it requires ...
Hate running the generator all night and getting little sleep? New lithium-ion battery systems are ...
Wet decking can compromise passenger safety on boats, particularly when boarding or disembarking. ...
Anyone who has repeatedly used a rag to clean gelcoat, paint and delicate surfaces has seen the ...
The new Mercury Racing 300hp Five‑Blade CNC Cleaver propellers are designed expressly to maximize ...
Beneteau may have outdone itself with introduction of its new Gran Turismo 36, manufactured in ...
Yanmar Power Technology has announced the development of a hydrogen fuel cell system for maritime ...
Kevin Monahan is a retired Canadian Coast Guard officer with more than 20 years of experience ...
The new 2020 PORTS Georgian Bay, North Channel & Lake Huron Guide is available for purchase at ...
Professional boatbuilders don't want to have to redo a job any more than a DIYer. Many choose Life ...