Mar 12, 2020

Last edition we talked about sealants to perform tasks like bedding and sealing. Other tasks like bonding, gluing, encapsulating and strengthening can be done using fiberglass, and the various resins available to saturate it.

A large portion of the boats on the water in Canada today are made using fiberglass – which is essentially a layer of fibrous stands, infused with a resin that will chemically react with a hardener, to make a strong, solid block. The way that the fibrous strands can be moved and molded, and the ways that resins can be strengthened have revolutionized boat building. As an extension of that, fiberglass care and construction are important to understand, so that repairs can be carried out.

Fibreglass is used in a number of ways aboard modern power and sailboats. It makes up the main hull shape, the bulkheads and stringers, the hatches and doors, the deck, coamings and cabin-top. The exterior is commonly a type of gelcoat that works (chemically) in a way that is similar to fiberglass. Modern boatbuilders are experimenting with carbon fibre and Kevlar to create deck hardware including cleats and winches.

Despite the marvels of engineering that fiberglass can perform, and it’s base it’s quite simple (once the chemistry is taken out):

Fibrous glass strands are infused with resin. The resin is a thick, syrup consistency that has had a chemical added to it that will react with the resin, causing it to change from a liquid to a solid. This solidifies around the layer of fibre, causing it to retain its shape, permanently, as a solid. Layers are added upon layers to the desired thickness of material.Layers can be bent, smoothed, molded and faired. The layers can be placed along a sandwiched layer of plywood, multiplying the strength, and effectively waterproofing the wood. The hardened fibres can be cut, shaped, smoothed and faired using common cutting and sanding tools.

Fibreglass Sheetfibreglass mat - a series of fibreglass strands pressed into a sheet. The sheet can be cut or torn apart to shape to fit.

The fibrous layer can come in many forms, namely: Woven mat (a pattern created by weaving, and the thickness of light wool), chopped mat (individual strands are compressed, creating a thick material, and cloth (a pattern created by weaving, but the thickness of cotton). Often, when creating a thick layer of fiberglass, these types of fibrous layers are alternated to provide strength and flexibility.

The resin alone can be thickened and strengthened, allowing it to be injected, puttied in place, or used as a fillet to strengthen a joint. Thickened resin is common in boat-yard repairs.

Epoxy and Resinthe left kit is a thickened epoxy - two tubes are included - one resin, one hardener - they are mixed in a 1:1 ratio. The bottle on the right is a polyester resin. 

The resin can have a few different types of chemicals: Polyester, vinylester and epoxy. Polyester resins are quite common on modern sailboats. Vinylester is used in applications where a thinner liquid may be needed, but generally costs more that polyester.

Epoxies are the thickest of the three, and they harden in a different way. Epoxies are becoming more and more common, and marketed towards do-it-yourselfers in a variety of ways (pre-thickened, and in delivery through caulking gun or syringe). Epoxy also has the advantage of sticking to anything – chemically, it will bond with polyester and vinylester resins, but also to wood, aluminum, steel and a variety of marine coatings (paint and varnish).

Thickeners are used in a variety of ways: to allow the user to ‘putty’ the thickened resin into gaps, holes or voids, to strengthen the resin so that it can be used structurally, and to create a glue, to bond parts together. The thickeners chosen can thicken, strengthen and to make the resin sandable – these include microballoons, cabosil and talcum powder.

MEKPa bottle of MEKP - a catalyst/hardening agent for polyester and vinylester resins

The hardening agent for polyester and vinylester resins is a catalyst called MEKP and is added to the resin at a ratio of 1-2%. Epoxies utilize their own hardeners (each brand uses their own chemical formula).

Resins come in metal cans (like an once or gallon paint can), and are poured into a ‘mixing pot’, and the hardener and thickeners (if any) are then added and mixed. The fibrous layers are laid out in their desired form, and the hardened resin is added, and a spreader used to spread and saturate the fibrous layer. Layers are added to layers, each being saturated with resin as it’s laid up.

Resins can be purchased with or without wax additive, and can remain tacky unless another additive (Styrene or Air Dry) is mixed in.

Whenever resins are used, safety and efficiency are the name of the game. Resins are undergoing a chemical reaction, and are harmful in a few ways: skin contact, breathing the fumes, and eye exposure. Skin can be irritated via contact, and proper eye protection and respirators are necessary. Resins are also quite messy – so protect the work area (and yourself). Finally, the hardeners act chemically, and will cure fasted in heat (even the heat of your palm, holding the mixing pot can increase the speed of the reaction. Epoxies also generate quite a bit of heat (enough to melt a plastic or paper cup), so be careful of your choice of mixing pot!

Next edition, we’ll cover the uses and techniques that are used on common repairs, getting you ready to hit the ground running when spring hits!

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. 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
The HO Excel Waterskis are your classic compression molded skis that are durable, but also have a ...
We all know that plastic and plastic waste is a huge issue globally. Driven by innovation and ...
Don't leave your toys at the dock this season. Wouldn’t it be great to take them with you? ...
Calder’s indispensable and thorough manual gives you detailed instructions for maintaining, ...
With hundreds of thousands of nautical miles under his keel, Kretschmer’s adventures have taken him ...
The Ronix Marsh Mellow Thrasher is a lightweight, 3 fin wakesurf board ideal for those wanting a ...
Color & Fabric Safe! Removes mold, mildew, algae stain, bird droppings, spider droppings, ...
This tough, fast acting cleaner removes heavy grease and oil, adhesives, glue, ink and marker, ...
Great for slippery trailer fenders, steps, and boat ladders SeaDek Step Kits are made from 5mm ...
FlexTred is a fast and easy way to prevent slip & fall accidents and is ideal for use on ...