Tuesday, 27 June 2017

Work in Progress

Below is a pic taken minutes before it started raining: the first set of plans I have sold, ready to be collected. As my local printer cannot do outsize A0 in colour I used a highlighter to identify the different components.

Although the customer will feedback on their suitability, I would be much happier if I had built a boat from them myself to be sure that they were usable.
I have an old skin on frame boat I built about ten years ago sitting on the racks outside doing nothing. As its coating of just enamel paint - an experiment which didn't work, has degraded in the sunlight I should be able to strip it and try out adapting the frame to the plans. As this boat has a keyhole cockpit would also enable me to produce an alternative to the ocean version, perhaps of a slightly longer boat.
Paddle and Window
Behind the paddle which has been cut to outline shape is the window to go in the workshop wall, courtesy of Freecycle a wonderful site. You may recall from an earlier post that the necessity of this came out of trying to laminate glass-fibre in a workshop with no ventilation and the effect - despite wearing a mask, that it had on my lungs.
Since then I have realized that I should have taken this step years ago. It is hard to believe how stupid I have been in taking ten years to realize that the environment in which one works is just as - if not more important than what you are making as it affects the outcome, both in terms of the product and the well being of the producer. These moments, days do not return.
For now; as I am working on paddle outside then cedar dust in the workshop should not be a problem. It is nice working by the back lane because I get to chat with the people passing by.
A must see
I watched the first of the BBC's series on Japanese art and life last night. It was absolutely inspiring.

It has me thinking that I should be focusing on producing beautiful things that work - and charge a price that reflects my input. I think I can do this better, and it is closer to what I am, than going down the glass-fibre route to produce kayaks more cheaply and quickly and make some more spending money.

Monday, 12 June 2017

Odd bits and maiden outing

Odd bits
This shows the footrest assembly laminated in place against the bow bulkhead, which I must say looks a bit rough in the photo.
Three things remained to do:
"Hot coat" strip round the join
A hot coat is gelcoat with wax in styrene added so that it does not remain tacky on the surface as gel coat normally does, and with alot of catalyst so that it goes off before it can run. There are no photos as the whole procedure had to be done really quickly: masking tape was laid down either side of the join where there was a small gap between the deck and the hull (behind which is the joining strip that was laid inside when the two halves were bolted together in the mould). The boat was laid on edge one side at a time and the hot coat painted very loosely and quickly along the whole length of the boat and right round to the outside faces of the bow and stern and then the masking tape removed immediately. The strip was gelling each time I was peeling off the second strip.
Filling the end spaces at bow and stern
I used about 100 grams of resin in the bow and a little less in the stern. The resin is catalysed etc and then filler and glass threads added to give it some  thickness and strength, and with the kayak on end poured through a hatch recess straight into the bow or stern. The bow got very hot as there was nowhere for the heat of the exothermic reaction to go so the bow of the boat was placed in a bucket.
Drilling the ends and fitting the grablines
Normally I would drill a 6-8mm hole and feed the decklines straight through, however as the end pieces were still hot I used a 4mm drill and fed the decklines through the thin line I took through that. To be drilled out fully later.
Maiden Outing
As I was out for less than an hour I though "voyage" was an overstatement hence "outing". So as not to miss the end of a good post election "News Quiz" on the radio I took my time changing, and the rest of Penzance Canoe Club had disappeared by the time I got on the water. These are the notes I wrote later:
1-1 1/2' sea, short coming into Mounts Bay from just West of South with the occasional swell too from the same direction and a good F3 wind blowing across from the west.
Bucket seat is too narrow and too low (or too low and too near the rear of the cockpit), I would have caught my back if I had tried a roll.
Felt nice and stable. Seemed quite hard to push through the water - but all the same did seem to clip along quite nicely (no GPS).
Poor directional control in a sea, went all over the place. A little better once used to the handling. Needs a skeg or less rocker.

Weather-cocked badly with wind on beam and rear quarter but not on the bow quarter.
Nice and dry deck sheds water effortlessly. Not a drop in the cockpit whole trip. Also seems to slope right down to the water due to the low sheer making it easy to get the paddle in close to the boat.
Went well into a chop. The wave piercing bow worked really well, didn't slam but pitched a little, not slowed.
Surfed waves effortlessly but hard to control direction

Overall Impression
 I was clearly paddling a kayak designed for rough water maneuverability in rivers, but the longer I was on the water the more I adjusted to quicker responses required in a sea that moved the boat around a lot.
The inadequate bucket seat which cramped the tops of my thighs prevented me from pushing the boat along and control with my feet. Weather-cocking was an issue but not as much as I feared. Although the V'd deck is quite high the sheer was so low as to give little to catch the wind.
Remedying the Faults
Abandon the suspended bucket seat. Use adjustable floor mounted unit with back strap. Fair hull and fit a retractable skeg. Can enlarge the cockpit later.
First of all though I need to build a paddle and put a window into the workshop.

Sunday, 11 June 2017

Cockpit, bulkheads and finishing off

Picture shows seat coated with PVA awaiting Gelcoat.

It took longer to laminate the cockpit than one of the halves of the kayak. The complex shape was built up from many different pieces of chopped strand mat which all overlapped slightly. As the moulding was four layers thick, the laminating process had to be repeated that many times.
Furthermore it was difficult to wet out the narrow radius of the cockpit gutter and cuts had to be made in the edges of the mat being moulded round the back of the seat so that it would sit without creases. When it was clear that the creases would not come out I had to cut with Kevlar shears into the wet out mat so as to overlap. I was concerned that I might have ruined them, but they cleaned up nicely with acetone afterwards. Later I read that they could be used on wet out glass, or even cured laminate without harm.
Because of the length of time laminating outside on the hot day I used less than 1% catalyst. With the thickness of the laminate in places I was also worried about heat build up during curing but it was not a problem.
Gelcoated mould clamped firmly in a Work-mate, CSM pieces ready for laminating in foreground.
Although four layers thick I was able to trim the edges successfully despite the resin being quite well set: hard work on the wrist with the Stanley knife and I went through a few blades. The rough edges needed sanding later. The completed cockpit and seat came out of the mould quite easily and the quality of the completed article was better than expected.
Newly "popped" seat cockpit in PVA skin.
I used pieces of 3mm epoxied ply cut from the deck of a kayak I scrapped earlier this year on this prototype but would hope to mould them in GRP once I have committed to one design. As I prefer them to run at an angle to the hull to give less of a hard point on the bottom, the angled section can be difficult to plot.
I built up the shape with wood scraps and a glue gun as shown below:
The outline rear bulkhead was easily plotted this way, and scribed onto plywood sheet.
You do not need a great number of sticks and points to get a good idea of the shape. It does not matter if the fit is not perfect so long as the bulkhead is not forced in to create a hard spot in the hull.  The gaps would be bridged by laminated glass-fibre which would put a flexible layer over the gap to seal and nothing more.
After cutting with a jigsaw the panel was laminated in place first of all around the edges and then overlapped right across to give a nice stiff bulkhead.
Photo, trial fit

This was relatively straightforward to scribe shape and fit. However the bow bulkhead had to be made in two parts as it was so much more difficult to get at. Before being bolted together sections were plotted inside the two laminated halves of the kayak at the same distance from the bow - where the flanges were marked. The shapes were determined the same way as described in the preceding paragraph.
This photo shows the bottom half of the bulkhead ready to go. The top half was then held in place with filler. Then the two halves were laminated into place and then joined when the lamination was taken across the whole bulkhead.
This was done with the boat upside down quite high up so that I could stand and reach down the hull.
Ventilation was a big issue in this job and I had all the fans on as well as using a vacuum cleaner hose inside the cockpit.
In the event the resin did not set properly at the early stage of this process, so what could be removed was and about a week later the whole process repeated, this time successfully. By this time I had become quite concerned about the risk to my health by the poor ventilation in the workshop which is really a large garage with shelving and a good floor.
The footrest flanges had been plotted some time earlier as shown below. These were bonded to the deck so as to give a better foot position (I find it too low on the hull side of the join with the danger of the feet going over the top and jamming necessitating a fail safe or full plate unit). Although the deck is thinner and in theory weaker, the bonding is to the deck where it is reinforced by two layers of joining tape.

The cockpit needed a bit of fairing to go into its opening. There will be a photo of this in place in the next post which will also describe the maiden voyage etc.

Monday, 5 June 2017

Joining the two halves and popping out a boat

Joining the two halves
This shows the two halves of the mould reunited before all twenty or so bolts were secured. Not only did this minimise the gap through which resin could drip but also helped to align the edges so that there was a smooth transfer from hull to deck without a step. Before doing this the excess gelcoat was removed from the flanges which were in turn given a coat of Mirror Glaze release wax and not polished.
Then the joined halves were put on edge, and a light fitted so as to see inside properly. A good vapour mask, and vacuum cleaner suction from inside the kayak were essential for a safe operation.
The rough edges of the cockpit were covered with masking tape, inside the working area looked like this: There was a high concentration of styrene from the resin in there, which without the vacuum cleaner, the mask - a good one, did not really cope with.
Strips of chopped strand matt were wetted out on a board nearby and then put in place through a variety of means. The pieces right at the ends were simply transported there on a long stick - which was turned over to put the soggy tape in place, and then wetted into place with an angled brush secured to telescopic pole. You can see the poles used in the foreground of the picture below. Where possible
strips were rolled into place from an old roller, having been rolled into place in reverse on the wetting out board. There is a double layer of strip in this boat - normal practice I believe.
Popping out a boat
Having undone all of the bolts a plastic squeege, normally used for spreading resin into glass weave was pushed into any gap that could be found between the flanges and then taken all the way round the edge until the two halves seemed to be moving - just a little. Then I used a pallette knife to work the smallest gap round the edge of the cockpit, and the two halves started to part.
And then the deck released quite easily.
The  hatch cover inserts were removed, again with a squeege and palette knife so that there was
something to pull on to pull the hull from it's mould. To start this process the squeege was taken round the edges of the mould:
Because of the design of the mould, the hull had to be popped out backwards. Once the squeege had gone all the way round the hull, then the boat could be popped out, lifting through the rear hatch aperture. This was surprisingly easy.
Much of the PVA skin would pull off, the rest was removed through washing with warm water.
to reveal the hull as shown. All of the subsequent work and difficulties would conspire to make this the conclusion of the easiest part of the process.
The next post will be about cockpits bulkheads and finishing off.

Sunday, 4 June 2017

Laminating in the moulds again

The last post
This post finished with a picture of the insert to extend the rear of the cockpit in its early stages.

Installed it looked like this, a bit rough - the idea being to fair the prototype first kayak.

Adding the PVA release agent
Before the polyvinyl alcohol release agent was applied, the two halves of the mould were polished with Mirrorglaze release wax three times. Now for the tricky bit - the PVA release agent which is dissolved in alcohol, and also apparently contains some water content beads badly on wax.
After just a few brush strokes (with a foam brush) it does this, and all you can do is keep moving it around until it begins to thicken through evaporation (the process is quicker in the warm).

As new parts of the surface are coated and the area under the release agent increases, one keeps going back to the parts coated earlier and so on until eventually you end up with an even non beaded coating in some areas and not in others

until eventually it all comes good, but it takes some time!
The inserts for hatch covers were added afterwards. All this took at least a couple of hours.
Laminating the two halves
First of all I gave the workshop a good clean and tidy, cleared the work areas put everything in what seemed the right place, cut the fabric to shape (by wrapping round the outside of the mould and cutting where the fabric meets the flange). The hull has a layer of 450gsm chopped strand matt followed by a layer of 300gsm woven rovings. The deck is pieced together from the offcuts, with a complete centre section added for strength where you need it round the cockpit and foredeck.

I used 1.4 kg of gelcoat on the hull and about the same on the deck and it was not really as much as I would have liked (1.5 would have been about right), also I was really rushed to finish application properly as it was beginning to gel at the end; 2% catalyst was too much on a hot day.

Here are the notes I wrote whilst recovering in between sessions with a cup of tea - and in clean air:-
Acetone dissolves nitrile gloves - use washing up gloves for cleaning brushes i.e. large over nitrile.
Need an extractor!!!
2 kg for laminating deck 2.5 for hull
The Kevlar shears were invaluable throughout the process
Find a better brush cleaning system
Find a better system for dispensing resin (the resin comes in a 20kg tub, so one has to use a cup or something similar as a scoop, with all the resulting mess)
Remove excessive gelcoat from the flange after finishing  - and before it sets very hard
The resin wetted out really well
Dispose rather than try to clean rollers
Use less than 1% catalyst on a warm day for laminating
Stick keel stiffener to laminate first and then glass over it
gelcoated halves
laminated deck

Hull with stiffener. The next post will describe how the two halves are joined together and then popped out of the mould.