Wednesday, 9 June 2021

Mast | Gluing Up

It was clear that gluing the mast together would be a big and time consuming task.

I did consider gluing the back piece to the sides first and adding the front piece later, but I thought the chances of the front piece fitting neatly into place were slim at best.

So it would be an 'all or nothing' approach, and I had better be fully prepared.

The test assembly showed as expected that I did not have anywhere near enough G cramps, so I purchased another 32. That's a strange number but the tool store offered 20% discount for batches of 16, so I got two lots. One lot would not be enough.

With the cramps taken care of I needed a long, flat surface to work on. The builder in the manual used folding tables for the task, so I did the same. My wife has purloined several of the tables which I already had, so I bought three more.

Here we are set up for gluing, with the mast supported on blocks and plenty of clamps in place for rapid deployment.

The bottom plug moved a little during the test assembly and I was afraid it might get pushed inside the mast when glued, so I screwed an eye into its end so I could pull or push it into place.

The actual gluing up session was somewhat fraught.

An awful lot of glue is required to coat the inside of the rebates and I found myself making new batches as I kept running out.

Also, foolishly, I glued up the top rebate on one side first so by the time I finished gluing the two bottom rebates it was starting to go off. I should have done the bottom rebates first and then the top ones at my leisure.

Anyway, we got there in the end despite the drama.

Here is the mast, glued up and curing.

I used 43 G cramps in total. If I had known it would require that many to make the mast I would have purchased them at the start of the build. They would have been useful.

So now I will leave the mast to fully cure before finishing it.

Mast | Cleaning Up The Rebates & Test Assembly

An initial test assembly of the mast revealed that the parts were not a perfect first-time fit. It was clear that some tuning was required.

The problem was that the rebates needed to be cleaned up.

These tools did the job.

This little bullnose plane is great for getting into corners, with its bullnose removed.

The last time I used it was to clean up planking rebates on the first boat I built, forty years ago!

A second and successful test assembly followed. It looked like this.

Looking good!

Mast | Making The Blocking

The mast has a solid plug inside the foot and the masthead to provide strength and for hardware fastenings.

Way back when I built the cockpit seatbacks I used some square section Douglas Fir to make blocking for the fittings in the seatback tops. That wood was in fact the blocking for the mast, so I had to purchase some more timber. Never mind ...

The plug for the top of the mast is 16" long and tapered on three sides, so quite tricky to make. I did it by cutting a piece 24" long to give me 8" to clamp in the vice while I planed it to shape, like this.

That worked well. The bottom plug is easy. It is 32" long and 1 1/2" square, so merely needs cutting to length.

Here are both finished plugs on the bench.

All the pieces of the mast are complete so next up is a test assembly.

Mast | Cutting The Side Rebates

The time came to cut the rebates in the mast sides.

As usual the build manual assumes that we have a  table saw, which of course I do not.

Actually I recently met a woodworker who does have a table saw and offered me its use, but it is really not feasible to transport sixteen foot long pieces thirty miles to his workshop.

So I invoked my original plan, which was to use a circular saw.

The saw blade can be adjusted to cut the required depth, but the saw itself needs a wide and flat surface to run along when cutting. This is a problem when cutting the edges of the side pieces.

I solved this by clamping a long piece of 2" wide stock between the two side pieces to provide a flat surface for the saw to run along. You can see how that works in this pic.

The piece of stock is moved and clamped along the sides until the cut is complete, and then the same thing is done to complete the cut on the other side piece in the opposite direction.

They are then turned over and the process is repeated.

This is the saw.

I bought it specifically for this purpose, and was worried that it might be overkill for the job. But it turned out to be just right - it requires a powerful saw to cut these rebates.

Here is the edge rebate cut in one side.

And here is the second cut in the other side.

The cuts in the faces followed. They were much easier to make. Here is the first cut.

It is an excellent saw and made a sharp and accurate cut, as can be seen here.

Here we see a finished side piece.

And here is a partly cut rebate in close up.

Looking good!

Mast | Marking Up The Side Rebates

The side pieces of the mast are rebated on both edges to accept the front and rear pieces, creating a box section.

Here the rebate has been marked up on the face of a side piece.

The rebate on the face is 3/4" wide, which is the thickness of the front and rear pieces.

In this pic I have used a cutting gauge to mark up the rebate on the edge of the side piece. This rebate is 3/8" deep.

The cutting gauge enabled me to make a line exactly in the centre of each edge. I then ran a pencil along the cut to make it visible.

I will be setting the circular saw to cut to the required width and depth when making the rebates, so will not be cutting freehand to the lines. The lines however will give visible confirmation that the rebates are being accurately cut. 

Here is a side piece in the vice marked up and ready for cutting.

The mast is certainly a time consuming project!

Mast | Making The Front And Rear Pieces

As with the sides the front and rear pieces were carefully marked up at each of the nine stations to achieve a smooth and accurate taper on both edges.

I selected the best surface for the outside faces and labelled them accordingly. You can just see the taper marked in between stations 3 and 4 in this pic.

The tapers were then cut and planed to shape. That didn't take long at all.

Next up is making the side rebates. Should be fun!

Mast | Making The Side Pieces

The rear edge of the mast sides is straight, so only the front is tapered.

The first step was to cut the taper with the jigsaw, like this.

The sides were then planed to shape on the bench.

Because they are so long it was necessary to clamp some lengths of straight timber to the bench to which the sides were clamped for support.

Here the front half of one side is being planed.

And here the rear half is being tackled.

In this pic we see both sides on the bench with rules, drawings and notebook.

The notebook contains the measurements for each of the nine stations for each side, including the width of the inside face between rebates. As here.

For such a simple design the mast is really quite complex to make!

Fastenings | Shopping List

I will need to purchase quite a lot of stainless steel fastening for fitting out because I have made some non standard additions to the boat i.e. removable drop board retainers and tabernacle backing plate, and opening portlights.

This post is a reminder to myself of what I will need, in case I lose the list.

That looks like an expensive shopping list!

Cabin Interior | Fairing & Filling

The time came to start work on the cabin interior by preparing it for paint.

The first task was to sand any rough spots and give it a good clean with the vacuum cleaner, as in this pic.

I wanted to fill all holes and fair all visible joins, so would need a fair amount of fairing compound.

I had previously tried using glass micro balloons mixed with epoxy for fairing, but you need a lot of balloons to make a small amount of filler and I wasn't that happy with the results.

What was needed was a good, ready-made filler. The kit vendor could not recommend anything, so I did some research and found this.

Made by Hempel for marine applications it can be used above and below the waterline and can be applied in layers of up to 25mm. Perfect!

You mix roughly equal amounts of dark blue fairing compound and white curing agent, and mix until it is an even light blue.

Here is some light fairing on the topsides join.

And here is the tabernacle backing plate.

I wanted to apply a small bead of fairing along all the joins in the cabin, and used a syringe to great effect.

Here is the syringe loaded with compound.

It was quick and easy to apply a bead along all the joints and seams in the cabin. I smoothed the beads out with a gloved finger. It looked good, like this.

There was really no need to extend this to the undersides of the cockpit decking, partly because it is not visible but also because that area was already very clean. When installing the decking I went to enormous lengths to make sure there was very little cleaning up to do by taping all the joints. It worked well Here is an area under the decking.

You can see that very little work is required to get ready for paint - a quick sanding along the seams before undercoat is all that is required.

I'm not looking forward to the sanding though ...

Floorboards | Covering Up Again

When the two outermost floorboards were back in place on each side I refitted the protective coverings, as here.

I sealed the coverings completely with tape because I intend to fair, sand and paint the interior of the cabin quite soon. And I don't want dust and mess getting into the bilge.

The manual says to do this when the boat is upside down for finishing the hull bottom, but it doesn't look too challenging to do it while it's upright.

And due to pandemic limitations on public gatherings it doesn't seem likely that I will be able to flip the boat before July, so I have plenty of time for painting!

Floorboard Problem | Holes In The Hull!

Months ago while working underneath the boat I discovered a slight problem. The screws that hold the outermost floorboards in place were protruding through the hull.

Here is one of them.

When fitting the floorboards I found that 1 1/2" 8 gauge screws were too long for the outermost floorboards - there simply isn't enough depth in the floors at that point. So I used 1 1/4" screws instead, hoping that would work. Clearly it didn't.

Holes in the hull are really not a good idea, so I devised a plan to fix the problem. I would remove the screws from the outermost floorboards, drill and plug the holes in the hull, and attach the boards to their inboard neighbours with a couple of dowels.

When I had some spare time I removed the protective layers from the floorboards. I had forgotten how lovely they are! Especially when seen through a porthole, like this.

I unscrewed the seventh and eighth outermost floorboards on both sides of the boat. Here they are on the bench.

I drilled a 6mm hole where the screws had gone through the hull and plugged the holes with 6mm Sapele plugs, epoxied in place. The plugs were trimmed flush and the floors sanded and repainted.

When fitting them I numbered the 8 floorboards on each side from the centreboard case out to the hull, port (P) and starboard (S). Thus P1 to P8, and S1 to S8.

To join the floorboards the first step was to drill two holes for an 8mm dowel in P8. Here it is, being drilled.

The floorboard is clamped in the drill vice, with a spirit level taped in place to make sure it is horizontally level.

The next step was to drill corresponding holes in P7.

It was important to make the holes in exactly the right place. Years ago I made kitchen furniture using dowel joints, and I remembered that I had a tool set for this very purpose.

The technique is to use a metal plug (6 or 8mm) with a raised spike in its centre. You insert the plug in the first hole and line the board up with its neighbour and apply some pressure. The spike makes a little hole in the second board, showing you exactly where to drill.

This is the marking plug, in place in P8.

And here is the resulting mark for the centre of the hole in P7.

P7 was then drilled for the two dowels in the same way. Like this.

Here are the two floorboards joined with hardwood dowels and a dab of epoxy glue.

I used the spacing gauge I made when fitting the floorboards to make sure P7 and P8 were 1/8" apart. It's just a couple of nails in a piece of scrap timber.

The same process was then followed to join the two starboard floorboards, S7 and S8.

Here are the finished floorboards, awaiting reinstallation.

The dowels were coated with Danish oil, as used on the floorboards.

I cut the heads off four bronze screws and fixed them in the countersunk holes in P8 and S8 with a dab of caulk, and refitted the floorboards with the screws in P7 and S7.

Job done!

Companionway Hood | Drain Holes

I had never been that happy that any of the drain holes are close enough to the deck to be effective, especially in the companionway hood.

So in a spare moment I enlarged the holes to allow full drainage in the hood, which slopes downwards towards the bow and will definitely hold water.

This is what the enlarged holes looked like.

That will do the trick.

Clear Coating | Second & Third Coats

While working on other projects I gave the completed components their second and third coat of clear epoxy resin, sanded to a P80 finish between coats.

Here is the tabernacle.

Here are the bowsprit, gaff, tiller, boom, and boom gallows.

And here are the rudder, drop boards, and drop board retainers.

That's quite enough pics of varnish drying, I think.

Mast | Marking Up The Sides

When the staves were complete and the joints cleaned up I marked up the sides for cutting.

I did it outside so there was plenty of room, as here.

The drawings are very good and easy to follow, but I labelled everything to make sure I didn't make any silly mistakes, like this.

The next step is cutting them to shape.

Mast | Making The Staves

The mast is a tapered hollow box consisting of four long staves of Douglas Fir for the side, front and rear pieces.

So the first step is to make the staves from two or three pieces scarfed together to create the 16' lengths.

When I made the first stave I posted that because the scarfs had been cut edge-to-edge rather face-to-face the joints are very long and need a lot of clamps when gluing up.

Seven scarf joints were required and I only possess 15 G cramps, so it took some time to make all four staves.

The process is simple. First we need to clean up the sawn joints with the block plane, like this.

Then the joints were glued and clamped and left to cure for a couple of days, as here.

The joints turned out pretty tight and will look good when varnished.

The next task is to fashion the tapered pieces for the mast itself.