Category Archives: Planking

Back in the Saddle

Enough with the distractions.  We’re back to work as of Monday morning.  I didn’t write yesterday because I’ve lost the cable to get the pictures off my camera and I figured nobody reads anything that doesn’t have some eye candy.  Today I went and got the spare cable from the big boat.

Yesterday and today were both frustrating, but for different reasons.  Yesterday we began by pulling the remaining metal staples from the port side of the hull.  Our hope was that the UPS guy would show relatively early in the day – usually it’s by around 10 or 11am.  Unfortunately, by 2PM there was still no sign of him, so we pulled the plug.  My dad went home and I puttered about waiting for Mr. UPS, doing some assembly work on the CNC router kit I recently purchased.

Blisters notwithstanding, here’s a big part of the reason we’re waiting for the plastic stapler.  Normal staple holes from a normal staple gun look like this:

But pulling the handle  that shoots those buggers a couple thousand times a day is a recipe for angry hands.  So we bought a narrow crown pneumatic stapler (which is what Home Despot had in stock).  Here’s what those holes look like when the staples are removed.:

No bueno.  And if you zoom out a bit, you can see the extent of the destruction.  Note that in a lot of places the grain of the plank actually splits a bit on either side of the staple.  This isn’t a fatal issue, but it does create a lot more work between this layer and the next:

Anyway, while my dad was away I did a light sanding on the hull to get the biggest of the ridges and bumps out as well, but … and this becomes relevant when we get to the source of today’s frustration – it didn’t occur to me to do a more meaningful fairing of the first layer to fill in the staple holes and minor gaps between boards.  I just figured we’d put a thick layer of adhesive between layer one and two, and that we’d start planking first thing this morning.

As mentioned, at 4:00 or so, the stapler arrived.

All hail the stapler that shoots plastic staples, and the staples it shoots:

All hail the unfortunate price tag!

So the first thing we did this morning was to take that handy new stapler and finish the portions of the port side that weren’t yet done.  We had to dial the pressure in to get the right penetration, but that only took a few staples to get right.  Once done we were off to the races.  Here you see, in glory that can really only be appreciated if  your hands are thoroughly blistered from pulling metal staples, planking laid with staples that never need be removed.

You also see a bit of fairing compound smoothed over them.  Which is the source of today’s frustration.  As I looked more closely at the hull today, I realized that it was going to be a giant pain to get a gap-free bond between the second layer and the first without doing some more aggressive fairing first.

This warrants a brief side note.

When building a laminated structure such as a cold molded hull, it’s really, really important that there be no air trapped in your laminate. Air is not strong.  Air creates opportunities for condensation, which can lead to rot.  Air is bad workmanship.  When laying a new layer atop an existing layer, you want the adhesive to completely fill the gap between them.  The layer of adhesive can be thick, but you really want no air in there.

Okay, so with all those little staple holes, minor gaps between planks, and ridges where one plank meets another, it just started looking really unlikely that we’d get a good layup without a ridiculously thick layer of epoxy, which would be heavier, costlier, and somewhat less strong than a thinner one.  And so, we decided to shoot today in the head and smear a layer of fairing putty on the hull.  Once that’s done, it needs to cure overnight.

So tomorrow is really what Monday should have been.  The day we move on to layer two.

First thing in the AM we sand the putty smeared hull down to a more workably fair surface, and then we can get to planking.  I’m hoping if we push really hard we can do both sides in a single day.  It will be a loooong day, but I’d really like to get all three layers of side planking done by the end of Thursday.  My dad’s away over the weekend, and while I can’t really move to planking the bottom withouth a helper, I can do a fair bit of prep work once the sides are done.

I did find a silver lining in today’s shortened day though as well.  More work on the CNC.  It’s getting close!

 

-Ben

Staples

My right wrist is throbbing.  I’ve iced it twice today and it’s still throbbing.  And I have blisters on my hand.  I’m sure there are all kinds of bad jokes running through your heads, but it’s entirely related to boat building, I assure you.  Yesterday we started the planking process using a staple gun similar to the one you probably have in your tool drawer.  These take a fair bit of pressure to pull and after 1000 staples (not kidding, there were about 250 left in a box of 1250 we bought that morning) my hand was killing me.  So we went to Home Depot and bought a $100 pneumatic stapler.  The only option they had was a narrow crown construction stapler. These are wonderful tools, and my wrist began smiling as I drove staple after staple with the mere pull of a trigger.  Unfortunately, however, the smile turned upside down today when it came time to remove them.  As this is a construction stapler, it drives those buggers deep.  Even at its lightest setting they’re fully bedded in the wood.  And there’s not much of a head to pull on to remove them.  Yes, we’re driving them through strips to facilitate their removal, but it’s still a nightmare getting them out.

Screaming wrist and blistered hand notwithstanding, the staples are out of the starboard side of the boat, and it’s really starting to look like a boat!  Yay!

We’ve also done about 75% of the first layer of the port side planking.  We would have finished but my dad needed to drive back to Palo Alto and the BART strike makes afternoon traffic a nightmare.  He wanted to leave early to try to beat the chaos.

The staples you’re looking at above (driven through the green strips to facilitate removal) are the last we intend to pull.  This afternoon I ordered a couple of boxes of Raptor composite (i.e.: plastic) staples and a special gun to shoot them.  It’s an expensive solution to the problem, but they sand like wood and can’t rust or rot so you don’t have to remove them.  They just stay in place and you finish the boat right over them.  After today, that seems worth nearly any price.

-Ben

And now for something completely different…

After weeks – months, really – of messing about with framing, it’s time to move on.  Today we begin planking the hull.

“Planking” is boat-speak for “covering the frame with a wooden skin,” and the process we’re using is called cold molding.  Many boats can be built by bending large pieces of plywood into the finished shape of the hull.  If you’ve ever heard of a “stitch and glue” boat, that’d be a prime example of such a boat.  For this to work, the hull can’t have compound curves because a single piece can only be bent into a conical section.  Our boat has looooots of compound curves, and so we can’t just bend a single piece of sheet lumber and call it good.  Instead, we take those 4″ wide strips and start laying them in next to each other.  To allow them to fit the curve, each one is shaped by hand, shaving away some of the edge so it will fit against the prior plank when it’s bent to the hull.  I can’t really photograph this process for you without a third hand, so you’ll have to use your imagination, but suffice it to say that it takes about 2-3 minutes to fit the edges together for each successive plank.

Then you take a bunch more time to apply adhesive and staple the plank in place.  The staples are temporary, and are shot through a piece of plastic or nylon that can be used to pull the staple back out after the epoxy has cured.

Each side gets three layers of WRC for a total thickness of about 1/2″.  Today, we were able to get the first layer on the starboard side.

This is a lot of work.  And each of those staples that goes in with the pull of a trigger is going to take a lot more work to remove.  Sigh…  These pretty curves create an awful lot of work.  Because the curves are pretty tortured in some places we need a lot of force to hold the planks in place while the epoxy cures.  I’m thinking it’ll take a couple of hours to remove all those damned staples.  We’ll find out tomorrow.

-Ben

Western Red Cedar

So the original specification was that the bottom and sides of the hull be planked with strips of 1/4″ Okoume marine plywood.  There were a couple of issues with this.  First, it would have been really inefficient from a material perspective.  The bulk of the strips need to be about 5′ long which, given that plywood comes in 4’x8′ sheets, means you’d be throwing away a huge amount of material.  And this isn’t cheap stuff.  Each sheet is about $100 and we would need something like 16 plank just the sides of the boat.  The second issue is that there are some really tight bends in this thing, and torquing 1/4″ plywood into them would have been a very difficult task.

After a bit of discussion with Timm, I decided instead to plank the sides with three layers of 0.166″ thick, 4″ wide strips of western red cedar.  Unfortunately, you can’t just go buy 4″x0.166″ WRC.  What you can buy is rough sawn 8/4 lumber in 10′ and 12′ lengths.  And that’s what we did. Then came the amusing step of converting the big lumber into small lumber.

To do that, we first surfaced the rough lumber and ripped the 8″ wide planks into 4″ wide planks.  Here’s a shot of the surfacing process.  I’ve got a Rojek 12″ jointer-planer that I picked up on Craigslist.  It’s proven to be a great machine.

Then we resawed the 4″ wide planks into strips known as veneers that were about 0.20″ thick.  Here’s the resaw operation.  It’s not hard work, but it’s mind-numbingly repetetive.

Finally, all the veneers went back through the planer to get them to a finished thickness of 0.166″, leaving us with a stack of veneers ready to be applied to the hull.  I don’t think we have quite enough to do the hull yet, but we decided not to mill anymore until we got a sense for how much it was going to take.

This is expensive wood – you’re looking at nearly $1000 worth of WRC in that stack – but it’s really the best approach to this part of the process.  It’s also quite likely that using WRC saves money since we’re throwing less away.  We shall see.  For the time being, we’ve got more than enough to start planking the hull!

-Ben