Scuppered inwales on a dory (or any boat for that matter)

I figured it would be a good idea to get a thread going for this particular modification since it isn't covered in the manual and there are at least a couple people working on it at the moment (myself for one). When I'm done, I'd like to put together an addendum to the manual for people who want to do this in the future. I'm working on a dory, but many of these issues will generalize to any stitch & glue open boat.

Some of these things are mentioned in threads here and here, but I'll summarize everything we've come up with so far:

  • The thwarts need to be cut down a little bit to allow them to kill into the underside of the inwale
  • You can use either oarlock sockets on risers, or top mount sockets through one of the spacer blocks on the inner rail if you want the sockets to be flush.
  • If you're doing a lug rig, the mast partner brackets need to go on before the inner rail (and the shape might need to be slightly modified for aesthetics where the rail butts against the bracket)

Anyone who is doing (or has done) this mod, feel free to contribute tips, tricks, thoughts about aesthetics, construction problems, etc.

-colin


20 replies:

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RE: Scuppered inwales on a dory (or any boat for that matter)

Good thread idea, will be interested in the comments.

On just one topic, which breasthook joinery method is preferred?  Inner rails to bow and breasthook inside of inner rails or breasthook installed first and inner rails kill into it?

 (Inner rails kill into breasthook):

https://www.google.com/search?q=slotted+mast+partner&tbm=isch&tbo=u&source=univ&sa=X&ei=jE-0Usq_Keul2AXNrYCoCA&ved=0CDgQsAQ&biw=1093&bih=474#facrc=_&imgdii=_&imgrc=bzjTW4VRjpS2pM%3A%3BHj4KTTwK9_bejM%3Bhttp%253A%252F%252Fi325.photobucket.com%252Falbums%252Fk365%252FTerryLava%252F2010%252520CY%252520Build%252FAftbhk1.jpg%3Bhttp%253A%252F%252Fforum.woodenboat.com%252Fshowthread.php%253F124371-New-Build-Caledonia-Yawl%252Fpage3%3B700%3B525

 

(breasthook installed first and inner rails kill into it):

http://www.clcboats.com/shop/boats/wooden-sailboat-kits/northeaster-dory-rowing-sailing-kit.html  then click "view main photo gallery" and go to slide 6.  Copy the image into MS Word and blow it WAAAY up and the breasthook joinery is easy to see.

 

Which do people like bettter?

 

RE: Scuppered inwales on a dory (or any boat for that matter)

Structurally, I don't think it matters as long as the rails are solid in the section under the breasthook. Aesthetically, It depends on whether the wood used in the rails, blocks, and breasthook match (as in the first link) or contrast (like the second). 

If the colors all match, I doubt you would notice any difference between the two methods. If they contrast you'd have some decisions to make. I think it depends on whether the color of the breasthook matches the blocks or the inner rail.  If it matches the blocks, kill the rail into the breasthook. If it matches the inner rail, run the rails underneath.

My preference would be to match the breasthook to the inner rail so you can extend the visual line of the inner rail all the way to the tip of the bow.

RE: Scuppered inwales on a dory (or any boat for that matter)

I'm trying to figure out how to space the scuppers along the side of the dory so that each of the bulkheads is under a block, and each of the oarlocks is on a block (though not necessarily centered)

As far as I can tell it isn't possible to maintain an even spacing for the entire length and have things match up.

How have people solved this in the past?

-colin

RE: Scuppered inwales on a dory (or any boat for that matter)

I was struggling with the same thing and a fellow builder gave me this idea...set your block length at 3" then space them accordingly.  The thought being the eye would not notice deviations in the spacing but would notice differences in the lengths of the blocks. 

So what I did was cut a whole bunch of 3" square pieces of paper, folded them in half and draped them over the side of the hull where each block would go.  Starting with putting one over each bulkhead, one over where each oar lock will go (I'm using top mount).  Then arranging more in an appropriate spacing...I think the spaces varied from about 4-1/4" to 5".

I copied JR Buckingham's boat  "Fawn" in the photo gallery...copy them into Word and you can blow them up to see the detail...think it's 4 blocks between the knee and the bow for example.

Then I did some mockups with clamps...check the link below then go to the next picture a dozen or so pictures.

 

https://picasaweb.google.com/114717787929554738224/BuildingWoodenBoatCLCNortheasterDory?authkey=Gv1sRgCKCBzczm_aKs2wE#5957817257206231202

 

Hope that heps...feel free to call...I havent determined the spacing yet because I'm going to do the inner rail last but I could get my pieces of paper out and document the spacing I came up with if you like

 

Curt  830/997-8120   curtdennis@msn.com

 

Would enjoy hearing other builder ideas!!

 

RE: Scuppered inwales on a dory (or any boat for that matter)

That's kind of the conclusion I reached, but I was thinking about going smaller with the blocks, maybe an inch or so, and around 2 inches for the scuppers.  My thought is that since I'll need to make a larger block to accomodate the oarlock, I can take up most of the error with that one block without it being noticeable.  The down side is that it means a lot more fiddly work.

I'll try to give a call tomorrow afternoon if you're around. Look for a 412 area code.

cheers.

RE: Scuppered inwales on a dory (or any boat for that matter)

I think I got it figured out.  I took the idea of laying the whole pattern out with scraps of paper (thanks Curt), and came up with the following:

  • blocks: 1 1/4" (though I might go 1/8" larger)
  • spaces: 2 3/8" +/- 1/16" as needed to make things fit
  • oarlock blocks: 3"

I put up some new pictures in the build journal. Having more blocks to take up the error means you only need to make small adjustments to the spacing to make everything fit nicely.

-colin

RE: Scuppered inwales on a dory (or any boat for that matter)

Final dimensions on the blocks/spaces are

  • blocks 1 3/8"
  • oarlock blocks 3"
  • spaces 2 3/16"

These dimensions let you have a block centered on each bulkhead and each oarlock location, though you still have to shift a few blocks by 1/16" to make everything line up. This also gives you 60:40 ratio of spaces to blocks which seems to be pretty common for scuppers (based on my highly scientific 5 minute google image search)

RE: Scuppered inwales on a dory (or any boat for that matter)

Oh, and based on the advice I received from the forum I'm using Titebond III for gluing up the blocks. You need to use C-clamps to get enough pressure, but it's worth it. Titebond 3 only has a clamp time of 30 min, so even though I only have a dozen C-clamps I still managed gule up all the blocks in one day. By the time I get a dozen blocks cut, sanded, and laid out, the previous batch is just about dry.

RE: Scuppered inwales on a dory (or any boat for that matter)

Curt-

I noticed from your gallery that you doubled the outer rail on the dory after all. Did you decide to skip the scuppered inwales to save time or did you change your mind about the aesthetic of having a thicker rail?

 

-colin

RE: Scuppered inwales on a dory (or any boat for that matter)

Colin,

Good catch...yes I'm still going to do the inner rails but just decided that since the inner rail stock is so small, two outer rail pieces wouldnt be too bulky looking and the strength of two .900" pieces (the outer rail size) for impact strength would be real good.

 

So I have a question for you on the Titebond III.  I build cabinets from time to time so I go through a lot of Titebond III but it never crossed my mind to use Titebond on the boat...I read all 8 of the forum posts that came up when i searched on Titebond.  Is that where you saw about using Titebond? Are there any other commentaries on using Titebond on a boat? 

 

Curt

RE: Scuppered inwales on a dory (or any boat for that matter)

I was originally thinking of using polyurethane glue, but at the advice of people here went with titebond instead. I stumbled across another website on boat building (I can't remember where) that also listed titebond as good alternative to epoxy in certain situations.

Obviously the two biggest drawbacks are that it isn't gap filling, and so needs tighter fitting joints, and it needs a higher clamping pressure (200 psi for medium woods, spring clamps only put out about 75 lbs.)  I made up a test block out of some scrap and smashed it with a hammer, and the wood failed in the grain (as I would hope). It's really nice for working with lots of small parts, like the scupper blocks, but since it's a lot less forgiving about having too much or not enough glue in the joint I would be wary of using it on major structural items.  The only places I'm using it are on the scuppers/inner rails and making up the thwarts--both areas that won't be under much stress, so even if I do end up with a weak bond in spots it won't create any problems. I'll try to get some more pictures up later today

 

-colin

RE: Scuppered inwales on a dory (or any boat for that matter)

I'm wanting enough strength in the inner rails that if someone lifts the boat (with all it's gear in it) by the inner rail it wont break off.   I'm confident the outer rail wont fail because it has 100% bond with no gaps like the inner rail will have between the blocks.  I wonder if Titebond III will provide as much strength as epoxy if the boat is lifted by grabbing the inner rail?

RE: Scuppered inwales on a dory (or any boat for that matter)

Yes it will, if you did a good job gluing. In either case, epoxy or TBIII, the wood should fail before the glue.

Laszlo

 

RE: Scuppered inwales on a dory (or any boat for that matter)

Laszlo,

Wow, I'm a first time boat builder so sine cabinet making is my background, all the cautions of not using TB outdoors come to mind, but I guess it's OK on our boats because it is encapsulated in epoxy?     If that's it, do boat builders use TB on other glue joints on a boat?

 

Also, I enjoy reading the info you contribute and saw somewhere you have a blog or website?  If so, I'd like to see it...could you pass along the link address?

 

Thanks!

 

Curt 830/997-8120

RE: Scuppered inwales on a dory (or any boat for that matter)

I updated my build album with a picture of my test block. I clamped it for 30 minutes, let it dry for 24 hours, then clamped one rail in the vice and broke it apart with a hammer (It took 2 solid hits to snap it). There's no evidence of any weakness at the glue joint, and this is about the worst case possible.

The only drawback to Titebond is that it is less tolerant of flexion and cyclic loading than epoxy (since it is a more brittle glue). I'm not going to lose any sleep over either one because once the inner and outer rails are assembled, the compound curve means that deforming it in any direction will be almost impossible (think of an arch bridge--ridiculously strong)

I don't forsee putting too much force on the inner rail, and even a person standing on it won't come anywhere near the failure point.

 

RE: Scuppered inwales on a dory (or any boat for that matter)

Just had another thought, if you want to get the best of both worlds use epoxy on the blocks for the oarlocks, and maybe where you would expect to tie your traveller, and use Titebond for the rest. That way you have the peace of mind about the strength, but you don't have to fiddle with lots of small batches of epoxy while fitting up the blocks.

RE: Scuppered inwales on a dory (or any boat for that matter)

Curt,

There's TiteBond and there's TiteBond. TiteBond III is not the same as the others. It's waterproof. Other builders use it to put together their strippers before glassing them.

The manufacturers are a bit schizoid in their ads and cautions. The ads say that it's the best stuff ever, waterproof and strong. The limitations say "Not for continuous submersion or for use below the waterline" and "Not for structural or load bearing applications". The specifications say that it passed the ANSI/HPVA Type I water-resistance test. A description of that test is:

Type I testing involves cutting the 6" by 6" assemblies into 1" by 3"
specimens, boiling them for 4 hours, then baking the specimens in a 145°F
oven for 20 hours. They are boiled for an additional 4 hours, then
immediately cooled using running water. The specimens are sheared while
wet, and the bonds must pass certain strength and wood failure
requirements to pass the Type I specification.

So between all that and the fact that the bond is stronger than the wood, I wouldn't hesitate to use it for your inwales, especially if they're going to be epoxied and varnished, or even just varnished. I used it for the mast cores and interior keel frame on my schooner, that's how much I trust the stuff.

SInce you asked, my boat building website is at: http://www.morocz.com/BoatBuilding/default.htm . There's a CLC WD12 build description at http://www.morocz.com/BoatBuilding/DuckBuild.htm . And there's build description for my version of Bolger's Single Handed Schooner (or Singlehanded schooner or His and Hers schooner, depending on who's talking about it) at http://www.morocz.com/BoatBuilding/SchoonerBuild.htm . That section has just been updated to show the boat's completion and launch. Sailing pictures start at http://www.morocz.com/BoatBuilding/SchoonerBuild18.htm . The schooner is not a CLC design, but it was built almost completely from CLC materials using techniques applicable to CLC designs.

 

Hope you made it through the snow OK, it's our turn here today.

Laszlo

 

RE: Scuppered inwales on a dory (or any boat for that matter)

Laszlo,

Here in South Texas it never got cold or snowy here....well the low one night was 25...where are you located?

Thanks for the info on the TB glue, interesting.

I'll surf your links in the evening after the daily sanding is done...thanks!

 

Curt 830/997-8120

RE: Scuppered inwales on a dory (or any boat for that matter)

I put up some pics of my trials and tribulations with fitting the inner rails against the transom, mast partner knees, and breasthook <here>

It should look okay when all is said and done, but if I had it to do all over I would have figured out to piece everything together as soon as I had the boat stitched together. That way I could have modified some of the pieces to make for cleaner and easier joints.

-colin

RE: Scuppered inwales on a dory (or any boat for that matter)

My verdict on using titebond on the blocks is that it isn't all that much easier than just mixing up one pump batches of epoxy. It might be marginally easier, but if you have all the blocks prepped and laid out you can just glue, clamp, and clean one batch at a time. I think the fact that epoxy needs lower clamping pressure (no need for C-clamps) might tip the scale in it's favor.

For gluing the inner rail to the blocks I started using epoxy because of how difficult it is to clean the squeeze out from inside the scuppers. A little smear of leftover epoxy won't even be visible, but excess titebond might be a problem when it comes to sealing the wood because epoxy doesn't always like to bond to it.

-colin

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