Re: Epoxy-gluing Strip Planks

Here are the first two strips:

Note that the strips are adjacent to each other. The thick piece of wood at the lowest part is not a strip plank; technically called a clamp which is the strong piece of wood that gives the top of the hull its shape.

The first strip (lower one) was screwed on to the bulkheads temporarily. Screws will be removed later. Had to be very careful not to spill any epoxy on those screws.

Since I am going for a no-visible-nails approach, I am using monofilament strings to clamp down-and-in the strips. The screwed-in first plank will be covered by the sheer-strake timber so ok to be a bit crude. Sheerstrake is like a "decorative cuff" at the top of the hull.

Interesting to note that, up to this point, the whole construction is epoxy-glued. No nails nor screws except for temporary fastening. I'm trying to minimize metal fasteners to mitigate corrosion risk.

String-clamping turned out much more difficult than it sounds. Tying down the strips require quite a lot of pull force. Pulling on the string cuts through bare hands. Tried wearing heavy gloves but could not make knots. Finally figured out a system of one hand gloved and other one free. By the time I finished gluing the 2nd strip on top of the first one, my batch of epoxy has hardened. Made too much.

Learning. Tomorrow will be a better day.

Re: Epoxy-gluing Strip Planks

[HTML]Pulling on the string cuts through bare hands[/HTML]

cant you use a turnbuckle for that purpose?

please continue with your wips...

never thought boatbuilding is this interesting!
😉

Re: Epoxy-gluing Strip Planks

I could use a turnbuckle but, since I have 12 builkheads, I'd have to have 24 turnbuckles (two sides in a boat). Also, epoxy gluing requires much less clamping pressure than recorcinol or the usual wood glue would require, so hand-puling may be sufficient. In fact, too much clamping pressure can cause epoxy starvation which would result in an inferior bond. Some boatbuilders would even get a Japanese saw and rake it crosswise over the pieces of wood to be bonded before applying epoxy to create the "grooves" where epoxy can permeate amd bulk up.

Thanks for your encouragement in continuing my WIPs. I have learned so much in this site that I feel I should, in some small way, contribute some experiences that, hopefully, would benefit someone.

Re: Epoxy-gluing Strip Planks

Just came up with an improvement on the strip planking by improvising a jig/clamp.

As I mentioned previously , didn't want to nail my strip planks because I'm finishing my hull bright (see through epoxy and varnish) and I don't want nail heads (or screw heads) visible. Also want long strips (without joints) so I got some hard-to-find 24 foot long planks and ripped them.

On gluing the strips to the bulkheads, tried initially the monofilament line technique described in an issue of Wooden Boat magazine.

Problem with this technique is that the fishing line often snaps before I could get the proper tension to clamp down the strips. It probably worked on small kayaks in the mag where strips were just about 1/4-inch thick. But mine were 15mmx22mm so they were less pliant. I often ended up "helping" the line with a clamp. But as I progressed with strip planking, I will soon outsize my clamps' jaws.

If I used thicker line, I'm concerned it may leave a weak gap between strips.

Came up with this jig:

And from the back:

Note that the jig is clamped onto the bulkhead. The bolt on top screws onto a nut that is embeded and epoxied into the jig so that as one turns it, the bolt goes through the nut then pushes down onto the strip; i.e., clamping it. I would install a jig on each bulkhead at the start of a strip planking batch.

The screws at the back are pan-heads, self-tapping, half-threaded (got them from my Kreg Jig kit). I lined up three screws on each jig spaced so that each will screw onto a strip, grab it, and pull it in. I could therefore install 3 strips in one go. I could increase the screws to, perhaps, 5 but I find that 3 for me is the optimal number: one batch of epoxy just enough before it hardens an more than three would be difficult to handle the bending at one time.

No worries about the holes the screws create. Since they're close to the bulkheads, they'll be covered when I fillet.

Doing 3 strips in a batch is a time-saver. I just clamp 3 strips temporarily and wet them with epoxy and apply epoxy glue all at the same time. I will then raise all three against the previously installed jigs (ontop of the previously installed layer of strips), using a clamp as a temporary hold-down while progressivelytightening the bolt and screwing in the strips.

Used the jigs on two batches of strips already. I find that, since I work on strip planking after work, I can do a batch of 3 each night. As I get faster with practice, I can probably do two batches (port and starboard) before the epoxy becomes too sticky but will have to make more jigs.

Will continue to improve on them for better clamping pads and also some variants where the bulkhead is at an acute angle with the strip.

Will also need to figure out special jigs where the strip meets the transom and stem.

Thought I'd share this technique for anyone here who plans to strip-plank.

Re: Epoxy-gluing Strip Planks

nice work Ding, very nice clamp idea too... still watching, please continue, we love pictures :cool::cool::cool:

Re: Epoxy-gluing Strip Planks

cool gluing jig bro..and making not one but lots of them made me scratch my head!
eh..how long will it take before you add another strip?
i dont care if it takes years to make your fine boat as long you document each step of the way.
wishing i could visit your "Hanjin factory" some day hehe

Re: Epoxy-gluing Strip Planks

cool gluing jig bro..and making not one but lots of them made me scratch my head!
eh..how long will it take before you add another strip?
i dont care if it takes years to make your fine boat as long you document each step of the way.
wishing i could visit your "Hanjin factory" some day hehe

Jigs were easy. Did them in one evening. Longest part was waiting for epoxy to cure...about 24 hours. In fact, I did such a sloppy job with them that I'm wishing they'd break so I could do them all over.;)

I do 3 strips in one batch, using 12jigs (one for each bulkhead). I could only add another 3 after 24 hours because I have to wait for the glue to cure first before removing the jigs. I could probably double my throughput by having a total of 24 jigs and doing 3 strips port side and another 3 strips starboard side.

Anyone's welcome to visit my dusty and grimy shop-garage. But call first so I can have some cold SanMigs ready!

Re: Epoxy-gluing Strip Planks

it just occurred to me Ding that you can modify your clamp rig to have screws on the outer portion too to hold the strips in place. 3 screws to hold one batch so to speak and the one on top as you designed.

Re: Epoxy-gluing Strip Planks

Thanks, Timb. I prefer not to put screws on the outside because they would leave visible holes on the hull, not very nice when I'm going for varnish finish. But I'm contemplating on a modification of your suggestion, having another arm that would have a bolt from the outside that would press on a piece of wood that would in turn press on the strips. But, so far the Kreg screws work.

Re: Epoxy-gluing Strip Planks

Thanks, Timb. I prefer not to put screws on the outside because they would leave visible holes on the hull, not very nice when I'm going for varnish finish. But I'm contemplating on a modification of your suggestion, having another arm that would have a bolt from the outside that would press on a piece of wood that would in turn press on the strips. But, so far the Kreg screws work.

How about toggle clamps on the outside instead of bolts?

Re: Epoxy-gluing Strip Planks

Thanks, Timb. I prefer not to put screws on the outside because they would leave visible holes on the hull, not very nice when I'm going for varnish finish. But I'm contemplating on a modification of your suggestion, having another arm that would have a bolt from the outside that would press on a piece of wood that would in turn press on the strips. But, so far the Kreg screws work.

exactly what I meant Ding. having an extra arm with 3 screws would serve as the hold down clamping force, if it marks, then you can use a sacrificial block or a plastic cap from a tea drink (I use C2 ice tea apple flavor caps:D)...

Re: Epoxy-gluing Strip Planks

Tried to get back into my boatbuild but realized the strip planks now need to be bent beyond the clamping force capacity of my improvised clamps.

Tried using ratchet straps and they work.

But I still need something to clamps the strips down into the bulkheads; straps work for in-between bulkheads.

So I need stronger improvised clamps. I figured, with my recent upskilling on metalworks, I can now weld together some improvised clamps using angle bars.

Started by boring holes on angle bars where I will JBWeld nuts into. (Welding nuts tend to melt the nuts!). The rest of the joints will be stick-welded.

You can see the prototype there beside the earmuffs.

All this boring seems to have dulled 4 of my new Norseman bits. Can anyone point me to some bit-sharpening shops?

Re: Epoxy-gluing Strip Planks

Nice project bro...

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