First Layer of Strips Complete

I put the last of the first layer of strips on yesterday. Here are a couple of photos of the bow of the boat. The angle isn't good because I have to stand on a box outside the shed and take the photo through the window. The result is that the photos are foreshortened.

Next job is to clean off the glue and sand the hull "flat" to remove the ridges where the strips didn't quite line up nicely. Also to fill in the small hollows, 2 on each side at the stern and 1 each side at the bow. I could just put strips over the hollows and fill the space with glue but I feel happier with this  two stage process.

Taking Shape

Reached another small milestone today when I put the last plank, in the first layer, on the stern. It is beginning to take shape and starting to look like a fantail launch. Three photos give some idea of the shape.

From some angles it looks as if there are some hills and hollows that shouldn't be there. I need to check by bending a fairing batten over the hull but the thought of doing that makes me a bit nervous! What do I do about them if they are there?

A Milestone!

Here are a couple of photos showing where the planking is up to. I put the last couple of planks on the stern, starboard side, this morning. Moved the tools round to the port side ready for the next few days work. Remember that the boat is upside down so you have to be careful about which is port and starboard!

Fitted Some Planks

A couple of weeks have passed since the last post and progress has been slow. Faced with the need to cut a lot of 100mm wide plywood strips I went looking for a small (tiny) circular saw with a fence. I found one with an 85mm diameter blade made by Worx. Here it is:

The saw part is quite good, light and easy to hold and the blade is narrow so less sawdust. The guide is a piece of crap! The black plastic guide is original, very narrow and difficult to keep against the edge of the sheet of ply. I added a pice of aluminium angle and this was a big improvement and showed up the next flaw - the guide is not parallel to the blade. There is no adjustment so I had to insert shims in various places to get the guide lined up. Now it works reasonably well.

While I was looking for the above I found and bought this device. I already had Ryobi batteries and chargers so the saw wasn't very expensive. It is hardly a boat building tool but it does an amazing job of pruning in the garden. I have a huge hedge to cut down and this saw makes the job so much easier.

Here's the set up for ripping the sheets into strips. The sheet is laid flat on a couple of trestles with a pair of 2x4s to support it. The first strips are easy to cut but the last 2 are a bit fiddly because the 2 clamps have to be moved to allow the saw to pass.

I ripped up 3 sheets of ply into 36 strips; this is probably enough to put one layer over about 2/3 of the hull. The two 2x4s on the bench are a  "vice" to hold the strips vertical so I can plane the edges. One of the 2x4s is clamped to the bench and in use the ply strip is clamped between them.

Fixing the first few planks involved me in a steep learning curve. Each plank has to be fitted to its neighbour that is already in place. To do this it has to be clamped in place leaving a minimal gap and a line drawn on it parallel to the neighbour's edge. It is unclamped and trimmed to the line and then test fitted. It is very important that the plank lies flat on the mould while these steps are being done. If it isn't flat there is a twist in it and it will not fit nicely against the neighbour. Don't ask me how I know this!

I covered the mould with clear 50mm wide packaging tape so the planks would not be glued accidentaly to the frame. Having done that I raided the kitchen and covered the whole thing with cling film. This was a mistake because I had to cut through the film to clamp the planks in place while fitting them. I have removed the film from the areas I am working one.

This next photo shows the planking going on the other side of the boat. The nearest plank with the clamps is being marked along the edge to fit its neighbour; this process is called "spiling".

By this stage I have fitted 6 or 7 planks to both sides of the hull and have established a routine. Clamp, spile, unclamp, trim edge, test fit with clamps, trim if necessary, mix epoxy, prime all surfaces to be glued including the long edges which is a pain, thicken epoxy, apply thickened epoxy to one of all mating surfaces, put plank in place and nail to mould starting at the keel, add a clamp at the gunwale, clean up excess epoxy and make sure the joint between the planks is full of glue. This takes about 45 minutes.

By this stage I am using longer (16mm) plastic nails because the original 12mm ones didn't hold reliably where the curve was pronounced on the bilges. The clamp on the gunwale probably isn't necessary but I have to put it on to hold the plank while I am putting the last few nails in.

New Tool In The Shed

After a long discussion about what I was proposing to do the Australian agent for Raptor polymer nails, brads and staples suggested that their 12mm (actually 1/2") long 15G nails would do the job. I was a bit sceptical because there would only be 7mm of nail holding the 5mm ply in place. He was confident enough to send me the gun without payment and for me to return it if it didn't work!

Here is the new tool before firing the first nail. It is a nice piece of work made in Italy.

Some testing on the bench showed that I needed to back off the depth control on the gun as far as it would go so that the nails weren't punched almost through the plywood. Once that was done I went back to testing on the boat. The next two photos show a couple of strips in place with the heads still below the surface. In the nearer strip I put in two nails but in the second strip there is only one except at the bottom where I put in two (the first three missed the frame!).

There's a gap between the two strips because they are parallel. When they are fitted finally the second strip   has to be trimmed to fit the one that it buts up against.

At this point I turned down the air pressure at the regulator and found that I can control the depth reasonably well. The heads can be buried a bit on the first two layers of ply because the depressions will get filled with epoxy. In the third layer the depressions would be a pain - they would need filling or the hull would be covered in dimples.

The frame is pine and pretty soft so I wondered what would happen with the second and third layers of ply where the nails will encounter more resistance. More testing with scraps of ply and various air pressure gave me this result. Backing off the air pressure a bit left the heads sticking up a bit above the surface. The photo shows three that went in too far and three that have been sanded back.

I'm happy with this result and can now get on with the last jobs on the frame before I pick up the sheets of ply early next week and start building the hull.

I realised that it is probably best not to build the stringers into the hull at this stage. Putting the fibreglass cloth inside the hull will be more difficult if the stringers are in place already. So I will take them out and put them in a safe place ready to be glued on top of the fibreglass - at least they will fit. Once these stringers are removed I will need to put in a couple more ribbands to support the planking at the bilges.

Last job will be to cover the frame with plastic tape so the hull doesn't get glued to the frame where it shouldn't.