Thread: Flathead

The shear strips were scarfed but most of the remaining joints will just be butted.
Fishing line is used by some people to help hold strips in place so am giving it a try. This is the reason for the random small holes in the forms. It digs in at the strip edges a bit but this is probably going to largely disappear with wetting and sanding (I hope).

Bevelling the strips is easy for the first few – not sure about later.

Can’t have too many clamps doing this. The bigger ones were good at this stage but will need other holding methods for when there are more strips.



The curve at the stern is tighter than expected and needs quite a bit of bevelling and twisting.



Had an unnoticed slip of one strip while gluing and this left a gap of about 5mm where there should have been a tight butt joint. The end of one of the strips had a deep scratch in it anyway so I cut out a section about 50mm long and inserted a patch. Had worked out how to use rubber bands for holding strips by this time.

Cool , couple of unedjumacated comments/question.

Strips seems thicker than I expected?

I reckon you could also do it half strip for the curvy bits and ply on the bottom with that design say a third up the stem even 6mm looks like it would take the twist OK, perhaps?

What glue?

Mike,

The strips probably look thick because they are only 15mm wide - in fact a couple in there are just over 10. They are 5 - 5.5mm thick with that variation being due to cutting them with a hand held circular saw run along a straight edge . Yes, I know I'm a wally but if I waited until someone I know could do them properly on a table saw then this thing would never be built.

Glue is exterior PVA. There are various opinions on this but I've seen people succeed with it and formed my own opinion which I will now stick with .

As for ply/strip hybrid construction I like the idea and was originally going to do a stitch and glue design with a strip deck. Then I stumbled on a quantity of WRC and the Kayak Foundry software so ended up with this. A number of people are now doing what they call strip, stitch and glue - which is basically using S & G plans but making stripped panels instead of using ply. They look really good and can be economical if you have a source of cheap timber eg recycled.

Two steps forward, 1 step back……

Had a limited time to glue a strip on the other night as I had to go and pick up my daughter later in the evening. This led to rushing things just a bit but managed to get the strip on OK and left it to set. The end at the stern didn’t seem to sit as well as it did in the dry run and further along it wasn’t as tight against the forms as expected. Viewing from the stern the next day it was apparent I had put the strip on upside down! Considering all the trimming and bevelling done with the block plane to make it sit right it should not have attached at all up the other way but I guess the rubber bands are good at compensating for a crappy fit.

So last night it was out with the heat gun and remove that strip, clean up the faces and reglue. Thankfully it was not a full length strip so the bow section was still OK. It seemed to go back on all right – certainly the fit was better right at the stern – but will have to wait and see how it looks when the clamps are removed.

One thing I’ve learnt this week is that this building method allows fairly easy changes/repairs.





On the positive side the bow is looking fairly good.

Looking good Bob.
How does it feel, putting together your own creation?
AJ

Originally Posted by b.o.a.t.

Looking good Bob.
How does it feel, putting together your own creation?
AJ

Like . Quite a happy little rodent at the moment .

..... but (there's always a but) the anticipation is killing me. The software says it's what I want but there's no way of knowing what the built version will be like until it's on the water.

Are you going to the wood show this weekend?

Working this w/e so not going anywhere pleasant or interesting.
There's a moratorium in force on new toys too, due to pending major works.
cheers
AJ

Progress is slow but I am trying to do something every day, no matter how small. The last strip put on the side was too difficult to get even close to the pinch in form 1 so the decision was taken not to worry about conforming to that form any further. Instead the stripping will now start from the keel. There is some doubt about how well these strips will meet the ones already laid in the bow area. They may connect smoothly or it may end up as a semi chine effect. Either is acceptable to me as long as it’s strong enough and functional.
The strips along the keel are 30mm wide and the first one was surprisingly easy to bend and twist with a heat gun. The edge was bevelled with the block plane up to where the twist starts to get serious. The plan was to saw straight down through the overhang after the strip was glued to the inner stem.

This didn’t end up perfect but is acceptable. The strip on the other side was bevelled to fit the first and glued up.

As one of the people who delayed your start by commenting on the design, I guess I should offer some words of encouragement.

ignore anyone who has doubts about whether you have chosen the right glue. You are using the same stuff that thousands of people have successfully used to create strip built kayaks. Yachts are a different story.

I am prepared to bet that even you will not be able to find those holes made by the map pins. An iron and a damp cloth will make them virtually invisible.

As I'm sure you have realised, putting those straight strips on the bottom of the hull is much quicker and simpler that the ones than have to bend sideways. They are also easier to clamp in place.

Did you try a few short sacrificial strips to protect the edge of the strips from the fishing line?

One of the many good things about strip built kayaks is that you can use recycled timber that would be unsuitable for most other applications. The deck of my current kayak is made from WRC lining boards I ripped off my daughter's bathroom wall when I helped renovate the house. The kayak is for her husband, so he is getting his bathroom wall back as a kayak.

It looks as if things are going well.

Some others who saw your design on the Kayak Foundry forum, I'm sure would be interested to see photos of the finished product.

Thanks for the kind words Allan. I will put a single post summary of the build on KFF with some pics when finished and probably a post in the Launchings forum too. There are some very skilfull and knowledgable builders over there. (Especially that bloke from Tuross Head )

Continued with stripping from the centre to meet the side walls. The first 2 strips on each side were left a bit long when gluing so rubber bands could be hooked over the ends. They were trimmed after the glue set. It’s looking more like there will be a sudden change of angle at some point as the bow widens out.

Have been slowly continuing the stripping from the keel line. Some of the mitre joints are not as close as I would like. It is very difficult to hold everything in place while test fitting and trimming. May end up putting a filler strip in later.

Also discovered that the keel line strips are out at the stern by about 5mm. This will not affect the shape of the hull by much if any but will show up when the skeg is added.

Bob, where the bottom strips meet the topside strips, it's common to have a "shutter plank" (strip). The last topside strip is not glued, but just tacked and is considered sacrificial. The bottom planks are brought down to it, then the shutter is removed. A batten is setup so you can run a router with a straight bit down the bottom planks, which makes a continuous, smooth cut. Next a new, spiled shutter is installed.

This may be too late for you, but you could do similar with the batten and router and plow out a 12 mm (or so) gap at the topside/bottom strip interface and fit in a "cheater", maybe one with a darker or light species wood to accent the intersection. You've probably all ready thought of this.

Par,

Thanks for the reply - some good thoughts in there. I had considered using a jarrah filler strip but the jarrah I have is only 1 meter long. How would I go trying to insert this in such short lengths? The joints in the cedar are only average and they were done with the ability to clamp them in line. A filler strip may be harder to hold in place.

The idea of the router on a straight edge has some appeal but I am very wary of using a router on the hull even with a guide. Apart from being somewhat clumsy I am unsure about how good the result would be when following an edge that has bend in 2 directions as well as twist. Would be more inclined to use the pull saw and clean up the edge by hand - although that has it's own set of problems as well .

You could scarf your Jarrah, but considering the cost of a couple of lengths, maybe better just to rip the edge off a plank long enough for the task.

I don't remember the adhesive you used, but if it's thickened epoxy, you'll be fine. If it's a PVA then you'll have needed considerable pressure along the joint surface during cure or you may have issues.

Working a router or a laminate trimmer which is much better as is a RotoZip or even a Dremel tool down a compound curve surface can be daunting. The way to make it work is to concentrate on one side only, as the place to bear the weight of the tool. On most boats this will be the topside planks. It's important to make each edge cut separately of course or the "wrong" side will rip out badly if you attempt a plunge and go type of cut. I usually make a foot for the tool so it has a bearing area on one side of the cut only, unlike a router that bears it's weight all around it's base. I would dread having to hand saw a shutter strip. I'd make a couple of dry run passes with which ever tool I elected to use (I'd use a laminate trimmer with a spiral straight bit) to insure I can handle the curves and the tool all the way.