The Arctic Tern Project

Volume 6                           Issue No. 1                        January 2009

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Chainplates; Rubrails; Toerails

Wow.  January went by fast and now we’re onto Volume 6 of the project reports (year 5 of the project).  Good progress this month with lots to show for it.

Chainplates

Ok, it was finally time to cut up that $600 piece of bronze I bought months ago and turn it into chainplates.  Egad!

 

I used a thin cutting wheel mounted on the trusty RAS to do the business.

 

Worked like a charm.  I could only cut about 1/16” depth with each pass but since it’s easy to adjust depth on the RAS this was no problem.  With four passes I was done each cut.

 

 

The cutting wheel does such a clean cut that you barely even need to touch it up after the fact.  The RAS has a ½” spindle coming out the back of the motor for attaching accessories and I’d being busting to try it out.  I figured out how to mount a sanding disk using this spindle and so now had a really handy sanding machine.  The RAS goes up another notch in my eyes.  A light pass on this was all that was required to make the edges beautiful.

 

Next, I trimmed off the corners with the RAS and then rounded them with the grinder and the RAS sanding machine.  Then I drilled the mounting and shroud attachment holes.  The one on the far right is a reject and the two unfinished ones next to it are for the backstay (I hadn’t figured out their placement yet so didn’t know how long to make them or where to put the mounting holes).

 

 

Ok, now it was time to drill more holes in the boat and fit those bad-boys.  I was a bit nervous about it; not exactly sure if the holes were going to end up in reasonable positions on the inside of the boat but there was only one way to find out.

 

 

I drilled the top hole first and then attached the chainplates to use them as a drilling guide for the remaining holes.

 

 

I drilled the bottom holes next and then through bolted them so the chainplates wouldn’t move around while I drilled the remaining two holes.

 

 

The holes all ended up in reasonable positions except the bottom hole for the forward chainplate was pretty close to a shelf I had put in (should have put that shelf in after).  It was workable though.

 

Ok, 24 holes drilled in the boat.  Whew!

 

Next thing was to make backing pieces for the chainplates.  I idea here is to strengthen the hull around the mounting point of the chainplates and distribute the upward pull into the sheerbatten if possible.  The top mounting bolt goes through the 2” thick sheerbatten itself so that’s good news.  I laminated some backing material from two layers of 18mm (3/4”) ply wood and shaped them out.

 

They turned out nice.  The front one is a bit goofy because it needed to be made in two pieces to span the shelf but it all worked out ok.  After nervously watching under-engineered chainplates for years in previous boats, these are reassuringly solid and well mounted.  They will be a joy to run my eyes over for years to come I’m sure.

 

 

More Holes in the Cabin Top

 

Alright.  While I was getting comfortable with all the hole-making I thought I’d cut the hole in the cabin top for the heater chimney.  So, first off, I positioned the heater and figured out where I wanted the chimney to go.

 

Then I made a little collar for the chimney cap (pretty ugly chimney cap but what could I do?).

 

 

I also made a trim piece for the inside.

 

Then I drilled an 1-1/2” hole through the cabin top and used the collar as a guide for the router to enlarge the hole.

 

 

The router bit was just not quite long enough to make it all the way through the cabin top.  In trying to get the last 1/16” I moved the bit too far out the collet and “zing” away went the bit.  Luckily, I didn’t damage the boat or myself but I still haven’t found the router bit.

Rubrails

The next step was to fashion some rubrails out of some planks for African mahogany I bought for this purpose.  Because the planks were so long I thought it might be easier to run them through my little table saw rather than muscle them through the RAS.  Unfortunately they came out looking like boomerangs and hockey sticks. 

 

I took the four lesser of the many evils over to friend and colleague Al Brunt and we fixed them up in his well appointed shop.

 

Next, I cut 12:1 scarphs in them using the RAS.

 

 

And glued them up.

 

After a day under the heat lamp I pulled off the clamps and gave it another day to cure.  I used hardwood dowels to peg the scarph so it wouldn’t move around while being glued.

 

They turned out well.

 

 

Next thing was to lay out where they would go on the boat.

 

And then lay out the taper at each end. 

 

 

Dimensions for the rubrails are 7/8” thick by 1-1/2” wide tapering to 1-1/4” at each end.  Only the last 8 feet at each end is tapered.  Next, I drilled the mounting holes for #12 x 2” flat-head stainless screws.

 

Then the chainplates come off but get labelled so they can get put back in the same place.  Before removing the chainplates I trace around them so I can figure out where they need to be let into the rubrails.

 

I partially test fit one of the rubrails before tapering it just to get an idea of what it will look like and see if the taper will look ok (it’s marked on the rubrail with pencil).

 

 

The taper layout gets a “thumbs up” so I have at it with the block plane.

 

This is kind of a rickety arrangement so when I taper the other ends I get smarter.

 

It’s important to keep things square.  Here you can see the intense concentration on my face as I’m trying to figure out how the hell things got so out-of-square so quickly.  It’s important to work fast too.  In the picture on the right you can see I’m planing so fast that my hands are just a blur! (Thanks Sonia for taking photos!).

 

 

Ok, so after the taper is done I fit the rails again so I can see if all looks ok before I round the edges (it’s hard to sight down a rounded edge).

 

 

I mark the places where the chainplates will be let into the rail.

 

Also mark where the ends of the rail will be cut off.  I’m going to cut the ends parallel with the transom and the bow and angled back 45 degrees.

 

 

 

Next step is to round-over the edge of the rail.  I’m going with a 3/8” round-over bit here.

 

Then I route-out the backs to accept the chainplates.

 

 

And then bend ‘em back on and re-mount the chainplates.  I grind down the head of the top carriage bolt to clear the rail (note these are just temporary fasteners; I’ll have bronze bolts for the final mounting).

 

 

Oh yeah.  I also figured out where to mount the backstay chainplates.  Pretty crazy angle but that’s what’s required for the split backstay.  The mounting points all end up in good, strong spots so I’m happy.

 

Here’re some more shots of the rubrail.  Looks good I think.

 

 

 

Note: the tops of the chainplates still need to be bent-in to match the angle of the shrouds I just haven’t quite figured out how I’m going to do it yet.

Toerails

Ok, on to the toerails.  I’d being trying to figure out for some time the dimensions and shape I was going to use for the toerails and how I was going to get it out of the material at hand ( one-by-whatever African mahogany).  Eventually, I had an epiphany and decided to make them out of two pieces stacked one on top of the other.  Here are some test pieces I made.  The inboard edge is angled out slightly and the outboard edge is 90 degrees to the deck.

 

 

Once again I tried cutting ripping the pieces on my small table saw but gave up and went over to Al’s shop after I made this noodle.

 

The bottom piece of the toerail will be  one continuous piece so these were scarphed together.

 

The top piece of the toerail will be in two pieces to accommodate the t-track for the headsail sheets.

 

Next, I marked along the deck-edge where the rail would go.

 

And then pre-drilled the lower piece of the rail for #12 stainless screws.

 

 

Then I made this device to help position the rail correctly while it’s drilled and mounted.

 

And then on she goes.  I was surprised at the “bendability” of the mahogany.

 

 

Next, I fit the top layer of rail.

 

 

 

 

I spent some time figuring out how I would position the stern cleats and their respective chocks and/or chafe guards.

 

 

 

I made this raised mounting block for the stern cleats and decided I would mount a chock set into the top rail about 3/8”.

Deckhouse Bottom Trim

Next thing was to tackle the trim around the deckhouse where it meets the deck.  This wasn’t strictly necessary to do next but I think I was avoiding tackling the sliding companionway hatch.  Anyway, I start off by deciding on the dimensions of the trim and then figure out how I’m going to do the corners.  I make a few templates and then transfer the dimensions onto ¾” stock.

 

 

One part of the inside curve of the corner block needs to be angled to match the cabin side.

 

 

Here they are in place.

 

Next Time

Finish the deckhouse trim.  Maybe do the hatches.