CANOE BUILDING: WEE LASSIE (PART TWO)

Building 'Wee Lassie' - The Photos

And What Did We Learn...

Fibre-glass Materials

• 105 Epoxy, 207 Hardener, breathing protection: Scomar Distributors. 30/176 South Creek Rd., Dee Why, NSW 2099, Australia. Ph: +61 (0) 2 9981 7444. Fax: +61 (0) 2 9981 7477.
• 740 Episize Glass Fabric, 422 Barrier Coat Additive, 805/806 Poly Mixing Pots: shipstore.com - I'm not sure I'd particularly recommend these guys as my order took weeks and weeks to arrive despite paying $60 for expedited postage.
• 300 Mini Pump Set, 406-7 Colloidal Silica, 800 Roller Covers, 803 Glue Brushes, 804 Reusable Mixing Sticks, 807 Syringes, 808 Flexible Plastic Spreaders: Adhesive Technologies Ltd. 17 Corbans Ave., Henderson, Auckland, New Zealand. Ph: +64 (0) 9838 6961. Fax: +64 (0) 9836 4849. These guys were exceptionally helpful!

I would also recommend comparing the items you get outside of the USA with those listed on the West System web site - several of the items I bought turned out to be old models under the same product number. Most annoying of all was getting my 300 Mini Pump Set home to find that it only came with the 5:1 hardener pump. I had to improvise to get an accurate 3:1 mix, as is required when using the 207 hardener (i.e. 3 pumps of epoxy + 5 pumps of 207 using the 5:1 pump set = a 3:1 mixture).

Fibre-glassing

The most important thing to say about this phase is "don't panic" - it really is as easy as Mac says. I had been deferring this job for some months (what with one thing and another, e.g. getting married) and had built this job up in my mind a bit. I had also been waiting for the temperature to decline - summer in Sydney is not conducive to fibre-glassing. But all my worry was completely unjustified - all the warnings about things happening too quickly, or with too much heat, never eventuated.

The next thing to mention is that I only loosely followed Mac's guidelines (for the first three coats of epoxy, anyway) and made heavy reference to the West System Use Guides. Mac uses the 'dry' method throughout in which each layer of epoxy is left to cure before proceeding. The cured layer is sanded to roughen it before applying the next and the bond between each layer is a 'mechanical' bond. An alternate method involves applying the next layer of epoxy before the last has fully cured (i.e. when it is still tacky, but not wet) - this allows each layer to form a 'chemical' bond with it's neighbour. A chemical bond is much stronger than a mechanical bond. I did this between the sealer coat, the 'glass coat and the weave-filling coat and was very happy with the result. One caveat, however, is to make sure the sealer coat is not too tacky when you lay the 'glass on (wrinkles are harder to shift). I'd also recommend having a person on each end of the sheet of 'glass and lowering it on from above, rather than rolling it onto the hull.

The glass fabric is magic stuff. Before I started I was concerned about fitting a flat sheet around such a curved surface and about how much 'cut & tuck' might be required, but my concerns were quite unfounded. The 'loose' weave means the fabric moulds to fit like a glove with minimal coercing. The West System epoxy and hardener were great, too. My other area of concern had been that the chemical reactions would happen too fast, especially as I was working at 25°C (77°F) (despite starting at 23:00 and working through the night). Again, no problem - if anything, I was worried that I'd mucked up the epoxy/hardener mix, the sealer coat took so long to get tacky! I had about 2 - 3 hours to kill between each coat and the 'pot life' of each batch of mixed epoxy was easily long enough to complete the job in hand. I used a roller in preference to a scraper, as I found this worked better for me - you'll need to use a foam brush to 'tip off' after the roller, however, as it lays more air bubbles than a scraper (using the roller slowly and not too firmly also helps a lot). Avoid pouring big puddles of epoxy mix and then 'squeegeeing' it out as this puts air into the coating as well.

The only slight bit of bother I had throughout the entire process was with the 'glass strips on the stems. As Mac points out, 'glass cut on a 45° angle shapes beautifully around this part of the hull. What he fails to mention is that 'glass cut this way frays at the edges very easily (especially during 'wet out') and that these rough edges are difficult to lay neatly on the hull. Mine ended up needing a good sand to take down. An idea I had afterwards (always the way, isn't it?) was to lay the strips on and then 'trim & peel' the edges off with a knife. Also, don't wet these strips out too much, as an excess of epoxy mix makes it more difficult to bed the strips in.

As far as safety stuff goes, I adhered to everything that Mac and the West System Health & Safety Guidelines said. I can recommend going with the full-on breathing apparatus option - a dust mask is just not good enough. I also had no patches of skin exposed and regularly changed my latex gloves. One additional recommendation is to tie supermarket bags over your feet - otherwise your shoes will be covered in splotches of epoxy in no time.

For the final two coats of epoxy I returned to Mac's 'dry' method which allowed me to fair the hull a little with the sander before applying the finishing coats. The final result looks stunning, even if I do say so myself. ;-)

Sanding The Inside

Using the orbital sander on the outside (convex side) of the hull lulled me into a false sense of security when it comes to using this beast with a 40-grit sanding disk. I was quite surprised just how easy it was to cause lots of damage really quickly when working on the inside (concave side) of the hull. A word to the wise: keep the sander moving across the strips at all times - don't ever stop in one place, and don't sand along the strips except where the surface is flat (i.e. along the gunwale strips and at the middle of the bottom of the hull). It took quite a lot of work to blend in the gouges made when I broke this rule. That said, it was all over very quickly and didn't make anywhere near as much noise as sanding the outside, so the neighbour's were happier.

Fibre-glassing The Inside

This was the worst bit so far. I predominantly used the same techniques as I had used on the outside of the hull. I had more success with using the scrapper this time, but still found using the roller was better for wetting out all the fabric quickly. One thing I would recommend is not dumping all the epoxy mixture into the bottom of the hull - if you pour it along the sides it is easier to spread around (and a good load of it ends up in the bottom anyway). Getting rid of bumps and bubbles was much harder than on the outside. Working away from the centre can pull the 'glass so much that it lifts and forms bubbles underneath - work the cloth back towards the centre if this happens and, if that doesn't work, cut the fabric over the bubble before it sets. This was also the only time where my epoxy mixture started to gel before I'd finished working - if you're having as much difficulty as I did spreading the epoxy around quickly enough, consider making your epoxy batches smaller. And don't get ahead of yourself - finish one section before moving to the next.

I was unclear as to how to treat the cloth at the gunwale. When doing the outside, I trimmed the cloth flush with the gunwale, as directed. If I had done the same with the 'glass on the inside there would have been a gap between the two layers of 'glass along the edge of the hull. Instead, I folded the 'glass over the edge and trimmed it so I had an ½" overlap on the outside of the hull. The plan was that the outside rail would cover this overlap, that the hull would be completely sealed in 'glass and that it would all look quite neat. In practise, it helped to force some clean-up work on the outside of the hull (thanks to the inevitable runs and splashes) and the 'glass along the edge was sanded away when it came to fairing the transition from the outer to inner rails (i.e. it was a waste of time doing).

Lastly, Mac talks about finishing inside each stem with strips of pre-wetted 'glass. I didn't bother with this bit - my intention was to make each bulkhead completely watertight, so I was not concerned about having un-'glassed wood here (I still sealed it with epoxy, of course). I hope I don't come to regret this bout of laziness later!

Fixtures And Fittings

Thanks to my non-standard mini-pump set-up (see 'Fibre-glass Materials', above) I was quite keen to coordinate, as much as possible, the epoxying work required during this phase of construction - I would have wasted precious epoxy and hardener otherwise. This meant re-ordering the tasks and scheduling things around the epoxy work.

I was also beginning to get quite pedantic about making all exposed/glued timber watertight. This extended to ensuring that the bulkheads aligned with an inner rail block on each side so that there was no way water could get in behind the bulkhead via the gaps between the inner rails and the hull. This 'careful' rail block placement was also applied to where the thwart was to be joined to the hull (which is visible in Mac's photographs, but not mentioned in the text). In order to get this rail block placement correct I had to locate where the thwart was going to sit and then use this as my 'rail block datum'. I held off cementing the last few rail blocks at either end of the rails until after the rail was mounted and the future location of the bulkheads was able to be judged. This process complicates Mac's instructions, but makes for a much tidier and sounder hull in my opinion (actually, I think Mac does this, too, but he didn't want to further complicate the instructions).

Another refinement I put in place was installing the thwart (complete with its long, supporting nails) before the outer rails. I installed the nails so that their heads projected most (but not all) of the depth of the outer rail from the hull and drilled holes on the inside of the outer rails to take the nail heads. This way I had no nails showing on the outside of the hull. Driving these nails in from the outside was quite difficult, even with holes drilled for them - the hull is not rigid enough to hammer against easily. Whilst we're talking about the thwart, I noticed in Mac's photographs that he had cut a curve in the underside of his thwart and I thought I'd give this a go. After a few false starts I pencilled on a large-diameter curve and cut it out with the jigsaw. A spot of sanding and a few passes with the beading bit on the router left me with a beautiful looking thwart (by the way, the dimensions for my thwart matched the dimensions for the timber used in the seat). Unfortunately, it wasn't until I came to install my thwart that I realised that I'd cut the curve into the top of the thwart instead of the bottom. Doh! The result still looks fine, but it was a good lesson in "double check your plan before committing to a cut".

I applied more artistic license when installing the bulkheads. I had decided to butt the bulkheads up against the inboard end of each inner stem which meant that they were supported from behind in the bottom of the hull. This also meant that I was able to use the corresponding hull moulds as a near-perfect starting point for the bulkhead templates. To support the bulkheads at the top I decided to locate my deck cross-beams directly behind them. I used a thin sheet of plywood to make each bulkhead backing and shaped these to fit snugly. In order to ease the laying of the cedar strips I glued a single strip down the middle of each backing plate and let this dry - that way I had a solid datum from which to work when laying the rest of the strips. After cutting and sanding the fully stripped bulkheads I then covered them with 'glass (waterproofing paranoia again, plus it matches the rest of the hull better). I installed the deck cross-beams and bulk heads at the same time. Instead of using 'glass bandages to support the joins I used fillets on the inside and outside of each bulkhead using thicker-than-glue epoxy/filler mix. To create the 'outside' fillet I used a Popsicle stick (nice, small radius) and to create the 'inside' fillet I used a mixing stick - this left a thin, neat join line on the outside and a good, thick fillet on the inside. If you try this, make sure you drag the stick across the fillet twice - once with the stick lying on the hull and once with the stick lying on the bulkhead. This ensures the surfaces remain nice and clean. Be aware that using fillets instead of 'glass bandages creates a visible, yellow join line where the bulkhead meets the hull - I like this as it helps to define each surface, but some people might not like the result - check out the photos and/or trial it before committing to this variation. Also, as this deck crossbeam/bulkhead placement wasn't quite as described by Mac, I cemented a spacer block (a spare inner rail block) at the top, centre of each bulkhead before installing the curved deck beams. This helped to create a deck overhang more like Mac's.

A final plan refinement involved what to do at the tip of each stem. Mac's photographs indicate that he opts to round each stem end, so I chose to do the same. Instead of relying on free-sanding a neat curve, I used a hole-cutting drill bit to cut a perfectly circular plug from an off-cut of mahogany the same thickness as the rails. I then cut this plug in half and glued one half to each end of the sawn-off outer rail ends. After a small amount of reshaping with the sanding block the result was very solid and pleasing.

After all these fixtures and fittings were installed it was time for a solid bout of belt sanding to fair the transition from the outer to inner rails and to prepare for installing the decks. This work undid a fair portion of the routing work that I'd done to prepare the topside of inner rails and thwart, so I'd recommend only routing the underside of the inner rails and thwart prior to installation and sanding (unless you're much more precise than I managed to be installing the inner and outer rails, that is!). I can offer one other bit of advice at this point: use your sanding board (that you faired the hull with) to fair the deck supports - it is very easy to get these out of true with each other when belt sanding, so a final going over with the sanding board helps to ensure that the decks will lie flat.

Laying The Decks

I made a feature strip for each deck that matched the theme of the feature strip used in the hull. I routed a bead onto both outer edges of each feature strip and then glued a feature strip down the centre of each deck frame. I let this dry before continuing so that I had a solid datum from which to work. Having a beaded edge on both sides of my feature strip meant that I could easily add strips to each side (i.e. uses the same logic that Mac applies to attaching the hull strips beaded-side-up). I only glued 4 strips to each side at a time and then waited for it all to dry before continuing. I applied strip-to-strip pressure by using masking tape and applied strip-to-frame pressure using weights and a yoke clamped across the strips (the strip-to-strip pressure tends to lift the outer strip, so check around the underside of the strips before leaving it all to dry). Make sure you clean-up as you go - this includes removing any excess glue from the deck frames that could hinder the placement of the next set of strips.

Once all the glue was dry it was time to try my (inexperienced) hand at some free-hand routing - first with a 'cut off' bit to trim the deck edges, and second with a rabbeting bit to cut a rabbet for the mahogany edge inlays. This job wasn't too bad once I'd learnt to trust the bearings on the router bits, but you could see how easy it would be to do lots of damage really quickly if anything went wrong during this phase! Next I cut some strips to glue onto the edges and some mahogany pieces to cover the tips of the bow and stern. Again, I held these in place with masking tape whilst the glue dried.

The final wood-working step involved cleaning up and sanding the decks and using the router to round over the edges of the decks and rails. I made a bit of a mess of this last step and wish that I'd done it all by hand with sandpaper instead.

Fibre-glassing The Decks And The Final Coat Of Epoxy

I cut a swatch of 'glass to cover each deck with enough over-hang to cover the deck supports (i.e. rails and curved deck beam). I wetted out the deck with epoxy mix and then immediately applied and wetted-out the 'glass. I had to nip the fabric that over-hung the curved deck beams in order to get it to sit flat. After settling the 'glass onto the decks and sides I let it all get tacky before I trimmed around the edges with a scalpel. I then applied the 'weave-filling' coat of epoxy mix to the decks, edges and bulkheads. After all was cured I sanded everything on the inside and topsides and applied a final coat of epoxy mix to everything (don't forget to do under the rails and thwart).

The Final Big Sanding, The Abrasion Coat And The Varnishing

Sanding everything smooth was a big, dull job. The exterior came up brilliantly again, but the interior was hard work. Use your orbital sander with caution and don't over-sand (very easy to do).

In applying the abrasion coating to the bottom of the hull I followed Mac's instructions to the letter. I followed the line of a pair of hull strips to mask out the area I was going to cover and squared each end (in preference to tapering each to a point - see photo). I applied 2 coats of epoxy mix cut with 25% 422 Barrier Coat, sanding between each coat. The mixture is thicker than epoxy mix without the additive, so I'd recommend not dolloping it on great pools with the expectation of spreading it around easily - cover the whole area in a light drizzle of the mixture and smooth it out with a foam brush instead. Peel the masking tape after the mixture starts to become tacky (don't be tempted to leave the masking tape in place for both abrasion coats!). I used the excess Barrier Coat mix to seal the hitherto bare timber on the underside of each deck overhang (including the exposed edge of each laminated deck framing member) - the Barrier Coat mixture should help to keep this potentially vulnerable area well sealed and watertight. I left this last spot of epoxy work to cure for a full week-and-a-half before moving to the next step.

After a light sanding of the abrasion coat I was ready to begin varnishing. Mac refers to applying "three or four coats of varnish" - I did five coats inside and out (the Australian sun is just too harsh for half measures). I used Norglass Weatherfast Marine Varnish for the three base coats and Norglass Weatherfast Poly Clear for the two top coats and was very pleased with the results (the slightly yellow tint caused by the epoxy coats was shifted back to a more neutral/reddish tint by the varnish - much more pleasing to the eye, in my opinion).

The Seat

I chickened out of attempting my first ever mortise-and-tenon join on my expensive seat timber. Instead I used wooden dowels (two per joint) and a dowelling kit (helps to get everything lined up). This is probably not as strong as Mac's seat (and mine is bigger by an inch on each side because I forgot to cut off the timber that would have gone to make the tenon), but I suspect my way was easier. After epoxying it all together I drilled the required holes and sanded everything off. I used a countersinking bit to countersink each drill hole top and bottom and then did some further edge smoothing with a round file and sand paper. Before coating the seat frame in epoxy I cut the arms to fit the hull. This was not as hard as I'd thought it would be. First I cut the arms to length (I needed to trim almost an inch off each) and then used a pencil lead poked through a hole in a Popsicle stick to transfer the curve of the hull to each arm. I then used the belt sander to grid each arm down to it's pencilled line. It all fitted very nicely (slightly to my surprise).

Next up was a full coating in epoxy, a light sanding and then three coats of varnish. I fabricated a swab-on-a-stick to varnish inside the drilled holes (water-proofing paranoia, again). I left this to cure for a week before tackling the hand-caning bit.

I had been dreading tackling the hand-caning quite a lot and so was pleasantly surprised to find that (most of) the task was quite enjoyable. I can recommend beginning each horizontal/vertical strand in an opposite corner as this means that the underside is more evenly covered (each pair of holes has a single cane running between them rather than two between some and none between others). The weaving of the diagonal strands at times seemed counter-intuitive, but I soon developed a good 'second sense' of when I'd made a mistake and was able to correct things before I'd got too much further. Study Mac's photos in detail! One difficulty Mac talks about is beginning the diagonal caning in the corners. I thought his alternative suggestion sounded even more complicated (no "pattern changes" for me!), so I had a go at starting in the corners and had no bother at all - just follow the photos and think before you start. The only less-than-enjoyable part for me was doing the binding strips. This was mainly because I thought I'd just about finished and then this bit took a couple more hours to complete - my hands were getting sore by then! Finally, when Mac replies to his own question of "how long does this process take" he replies "about the length of a baseball game" - for all the non-Americans out there this process took me about six or seven hours.

So, did it float ..?

Final weigh in (including seat, excluding paddle): 14.5 kg (32 lbs).