Thursday 19 September 2019

Getting Ready To Fit Floorboards | Spacers & Marking Gauge

While I pondered how to begin actually fitting floorboards into the boat it became clear that accurate positioning of boards and screw fastenings would be critical. Any discrepancy would be very visible and unsightly.

To start with, the boards have to be uniformly 1/8" apart. To achieve this I made some spacers, using nails which are exactly that in diameter fitted into holders made of scrap ply. Here are the spacers.

They look a bit lethal, don't they?

And to ensure that the screw holes are always in the same place on every board, I made a marking gauge. Here is it is.

The idea is to slide it along the edge of the board until the upper and lower pencil lines exactly align with the floor, and then use a bradawl to mark the screw holes through the two holes drilled on the centre line.

Tests show that they both work well.

I can't claim any original thought here. I copied these tools from another builder's blog. Thanks Ron!!!

Getting Ready To Fit Floorboards | Making Rebates

As recounted in the previous post, I had to sister the cleat on bulkhead 2 to compensate for it being attached 1/2" too high.

The floorboards are 3/4" thick, so I would have to cut a 1/2" rebate in the face of the forward end of the affected boards for them to sit snugly against the bulkhead.

I decided to use the router and a 1" two flute cutter, with the fence attached.

I also made a jig to hold the boards securely in the correct position, and to provide a long and even face for the router fence to move against.

Here is the set up with a board in place before the rebate has been cut.

And here is a board with the rebate cut, nice and clean.

Eight boards in total butt against the bulkhead, so I selected eight lengths of Ash and chose which face to be uppermost, and cut the rebates.

It has been a lot of extra work to remedy the unexplained error, but I am confident that the outcome will be satisfactory.

Getting Ready To Fit Floorboards | Fourth Cock Up

When the deck and cockpit support cleats were all fitted I was very excited to break out the timber for the floorboards and to start preparations for making and fitting them.

I had long been aware that floor 3 was a fraction lower than the other floors, but I wasn't worried about that because a thin shim would be easy to fit - if indeed it was even required .

So to check out how level the floors were I laid my newly acquired long level across the floors, and immediately discovered that I had a hitherto undetected and serious problem.

The cleat on bulkhead 2 where the forward end of the floorboards land is 1/2" too high. Not just a few millimetres, which I could probably understand and live with, but a big fat half of an inch. Here is the level with a steel rule attached showing the actual as opposed to the required level of the top of the cleat.

How did that happen? I still can't work out what went wrong.

Initially I thought that bulkhead 2 must be too high in the boat, but it isn't. It is correctly positioned and the cleat is exactly where the drawings say to fix it, so I am at a loss to understand it.

I didn't immediately panic and do anything rash, and I posted on the CLC PocketShip forum asking for advice. It seems that this has happened to other builders, at least one of which hacked out the cleat and fitted another one. There was no way that I would do that … so after a bit of thought I decided to sister the cleat i.e. fit another piece onto it but at the correct height, with another piece behind it to butt up against the bulkhead.

I liked this idea because it would give the floorboards more of a ledge to land on and allow the fastenings to be a reasonable distance from the bulkhead, rather than right up close to it as designed.

So I made the sister cleat and dry fitted it, as here.

It worked very well, and I was so pleased with it that I decided to sister the cleat on bulkhead 8 as well, where the aft end of the floorboards land, to give more room for the fastenings.

Here are the two cleats which I made.

 The one at the top is the cleat for bulkhead 2. You can see the backing piece fitted to its rear face which sits under the original cleat and butts up against the bulkhead, making one single solid fixture.

Here is the extra cleat fitted to bulkhead 8, held in place with temporary screws.

And here is the additional cleat glued up on bulkhead 2.

The floorboards will require a rebate to be cut in the front face to fit over the original cleat, hiding the sister cleat from view. That's the next job.

Fitting Deck And Cockpit Cleats

Now that the finish of the hull interior surface was complete, it was time to fit cleats to support the rear deck and cockpit. This promised to be quite a big job, and required some careful thought and planning to make sure that the cleats go in the correct location.

I started by dry fitting cleats to bulkheads 7 and 8. Their location is obvious and fitting is straightforward.

Here is bulkhead 7.

And here is bulkhead 8.

The location of the cleats on the transom is marked out by extending a straight edge from the bulkheads back to the transom itself, like this.

I taped a steel rule to a builders level to achieve this. I initially tried to use a short level which I already had, but it didn't work very well and after wasting some time getting inaccurate results I just went out and bought a good long level. Problem solved instantly!

The same technique is used to mark out the location of the long cleats on the inside of the hull, as here.

And here.

The long inside cleats are held in place with temporary screws through the hull, like this.

Here are the transom cleats, held in place with temporary screws.

I found that I had to mark out and cut slots for the deck frames in bulkhead 8 myself, as here.

There are no pre-cut slots and the manual offers no guidance on positioning, so I just deduced it from the drawings and by lining up with the slot in bulkhead 7 and the cleats on the transom.

I hope I've got it right! The hull hardware package should arrive soon so I can check where the cockpit deck hatches will go before I deck over the frames, just in case remedial action is required.

Here are the rear deck frames, dry fitted.

When I was satisfied that everything fitted properly I profiled the exposed and visible edges of the appropriate cleats, using a router and a 3/8" roundover bit.

For this job I set up the router table, as above. The table is attached to a piece of kitchen benchtop so it is portable. I ran all the cleats through the table in no time at all.

Then I glued the cleats in place, with plenty of clamps. Like this.

When gluing the long port side cleat in place I immediately found that I had not used enough temporary screws. Friction holds the cleat when it is dry fitted, sprung into position with just three screws, but when glued up it slides out of position. I had to quickly drill for and fit more screws. Nine fastenings are required on each side to hold the cleats in place.

Here are the transom cleats glued in place.

While working on the footwell support cleats I also attached cleats to the footwell sides and test fitted them, as here, to make sure everything is in the right place. It all seems to fit nicely!

The final thing I did was to glue the rear deck frames in place. In the above photo they are simply dry fitted.

Now that the cleats are all done it seems incredible that the next job is to fit the floorboards before we deck the boat!

Forward Deck Sheerclamps

The interior of the bow compartment was finished and the lower breasthook installed, so now was the time to add some cleats to the hull sides for the forward deck to sit on.

The build instructions say to fix a thin strip of wood to the hull sides in the bow compartment, but do not say anything about the storage compartment immediately behind it. This seemed odd to me because it would make sense to tackle both compartments at the same time.

I looked ahead in the manual to see how the forward deck is joined to the hull sides in the storage compartment, and to my horror it calls for a fillet to be applied to the join.

Now, it was hard enough making a good job of the fillets in the hull when they were easily accessible and in the bottom of the boat ... but applying a fillet to an overhead join, working on your back through a hole in the bulkhead? No, I don't think so!

So I used the forward deck panel as a template to make a jig, and laminated sheerclamps to run the whole length of the deck through both compartments. Each sheerclamp is made of two strips of 9mm marine ply.

Here are the sheerclamps, glued up and curing.

When cured I cleaned them up and cut them in half to create sheerclamps for each compartment. In doing this I managed to ruin one of them, so had to laminate another one, as here.

It was no hardship. The jig was ready to go and I have plenty of scrap ply.

Then I shaped and test fitted the parts, and when happy with the fit I glued the sheerclamps in place, like this.

Lastly, some time later I faired the tops of the sheerclamps level with the hull. As here.

I think this offers a much better landing for the deck than a thin strip of wood and a nightmare of a fillet! And it was fun making them.

Fitting The Lower Breasthook

With all the fibreglass and epoxy work complete in the bow compartment, the time had come to fit the lower breasthook.

I was initially a bit wary of this activity.

It was obvious that the breasthook would not be a perfect first fit and would need to be bevelled to sit cleanly against the sides of the hull.

And it would require a powerful clamp to pull it into place and to push the sides of the hull outwards to accommodate it. This was the bit I was nervous about - I was concerned that something might break if it required excessive force to pull the breasthook into place.

The task of bevelling was straightforward and quickly achieved with the jack plane.

When it was a good fit I clamped it in place for the dry test fit. The hull sides creaked a little as they expanded outwards, but all went well.

Here it is sitting snugly in place. Note the predrilled and countersunk holes for screws, and the block over the stem to support the clamp.

When I was happy with the fit I glued it in permanently with thickened epoxy, which actually helped it slide smoothly into position.

Here it is, glued and screwed in place.

The build manual says to use a couple of screws but I chose to use three to be sure. They are 8 gauge 1 1/2" silicon bronze wood screws.

Job done!

Final Coat Of Epoxy Inside The Hull

The second coat of epoxy inside the hull was left to cure for a few days to make sure it was nice and hard, and then I sanded it smooth.

Then I applied the third and final coat of epoxy and again left that to cure properly before sanding it to an even and matt P80 finish.

This all took a little over a week to complete, during which I did little else.

I took plenty of photos but sanding is such a tedious activity, and I can't really see much point in boring readers with lots of pictures in which nothing much actually happens ...

Here is the stern compartment half way through its final sanding, showing the contrast between before (port) and after (starboard).

And here is the hull interior, finally sanded.

At this stage the centre board case is yet to be coated, so more sanding still to come!

At long last I was able to pencil in the final dates on the spreadsheet on my cupboard door.

On a practical note, it would have been impossible to keep track of this activity without a log of this kind.

There are nine bays in the hull, each with a port and starboard half, to be clear coated and sanded a total of three times. Easy to lose track of what you have (or have not) done, especially over an extended period of time as in my case.

Well, that's possibly the worst part of the build out of the way. Hooray!

Finishing The Centre Board

In between other tasks I found time to complete the centreboard. It had been sitting in a corner of the workshop while the third and final coat of epoxy cured nice and hard.

Here it is being sanded.

I sanded both sides to a P220 grit finish.

The surface is now as smooth as glass. I have put it in the house, out of harm's way until required for installation.

This is the final activity in Chapter 1: Keel Assembly, so we can now say we have completed a whole chapter of the build manual!