Why not another CS17 Build Thread? Here's #366

[mattp]

Seat frame dry fit: this was a pleasant step and gives a glimpse into the future of the cockpit layout.

[mattp]

I finally got brave enough to put some glass on the centerboard today. Though I am happy with the final shape, you can see a history of fillings, repairs, and afterthoughts showing up as wood flour thickened epoxy stains. I think it will have a good finish once painted that I guess we will have to capsize to appreciate.

[mattp]

It's been a while since an update but we have been making steady but slow progress. Much of the effort now is towards completing the steps that will allow us to flip the hull just once to finish the bottom completely.

Glassed half of the rudder. My plan is to have overlapping layers on the leading edge for a little more protection from dings.

CB trunk glassing and assembly:

Hull stringers aft of forward bulkhead:

EZ Bake oven for epoxy curing:

CB Trunk dry fit:

[LennieG]

Looking good!

[mattp]

Thanks Lennie! As long as you stay a step or two ahead of me (with photo rich posts), I'll be alright!

[russell]

Looks like your doing a great job on the boat!  I want the green house for tomatos in the winter!!

[mattp]

Thanks Russell! Maybe that's one good thing about only posting cell phone pictures:)

It's amazing how good of a building space the greenhouse has been. The only issue is that I have noticed some discoloration of some of the ply that has been exposed to the sun. We will need to start covering up the boat and any staged ply.

Tonight we planned to set the cb trunk, fillet and tape, but decided that was a bit optimistic and just tacked in place. This way the filleting and taping will be less stressful without the risk of the assembly shifting.

[LennieG]

You guys are flying!

[Dnjost]

Did you do the CB trunk per plans by scribing to the bottom, or build longer with plans to trim after flipping.  I am deciding right at this very moment whether to add an inch or two to the lines, then cut the hole to the outside of the trunk, rather than the inside.  

[mattp]

I laid out the trunk sides exactly according to plan except that I left an extra inch along the bottoms for trimming to fit our hull.  Then I trimmed the bottoms of both sides until everything fit well and the upper frames of the case were level with the seat frames.

 

If I understand your idea correctly, you will need to make the opening in the hull before the structure of the case is in place.  I am not sure what would happen, if anything, but I would be worried about something springing in one direction or another when making that cut. I may be off but that is my feeling about it.

[Dnjost]

I saw photos from one build where the entire centerboard trunk protruded through the hull and held from falling through by temporary wood cleats held to the proper height.  At this point, I am not sure it is worth the effort as after much careful measuring the trunk as laid out will fit almost precisely.  Although II do see the need to bevel the kingpost(s) to match the angle of the bottom prior to laying out the other side and trimming the hole for the board.    These photos are from the disc that comes with the plans.  

 

 

[mattp]

I have seen these pictures on the CD and I guess I didn't understand what I was looking at until now.  What is the benefit of having the sides protrude through the bottom?  Is it so you can cut the opening before setting the trunk?

 

Right now, our trunk is tacked in place but have no opening at all through the hull.  I am not too worried because I am fairly certain we can run a boring bit with an extension through the top or just measure and drill through the bottom large enough to get my pull saw in.  This okoume drills, cuts, planes, and sands so easily (should I be concerned about this?), that I think that the opening will be pretty easy work.

 

And yes, the king post ends need to be beveled, more so with the forward one.  The starboard trunk side, in turn will be shorter.

 

Its good to know that there are others out there working on the same steps.  Please come back often!

[Hirilonde]

  What is the benefit of having the sides protrude through the bottom?  Is it so you can cut the opening before setting the trunk?

The only one I can think of is that it makes scribing the bottom of the trunk to the hull accurately and in the proper location easier.  But because the hull of these boats are tortured (twisted and bent) plywood you risk distortion cutting the hull before the trunk is attached and supporting the hull at what will become the hole.

[Dnjost]

I am in Dave's camp with this one.  No need to put a larger hole in the bottom as this skin is pretty stressed already.

 

I am putting in my trunk right now, but it is all a dry run, using bronze screws in addition to glue (will glue up when the weather warms).  So far, I have set up a temporary cleat at the stern edge to help keep all in line and provide temporary vertical support to stern kingpost. I am using a cheap luan doorskin to make patterns for the actual trunk sides, rather than butcher a $100 piece of marine ply.  Photos coming later today (if i can locate the 5/4 X 2" mahogany board I want to use for the upper CB cleats).

[Peter HK]

I fitted the centrecase by cutting a hole large enough to fit the case through then scribed with a pencil (which took about 30 secs), cut off the excess, and was ready to glue/glass it in. As you can see from the photo at this stage the seat uprights, keel batten and bottom stringers were all in place so the hull was very rigidly held. I'm sure the hull didn't move/shift or distort to any detectable extent.

 

I'd do it the same way again.

 

Cheers

Peter HK

[Dnjost]

Looks good Peter.  I am sure that is much faster.  I probably would be done by now.  

 

http://jostboats.blogspot.com/  My last posting is regarding the layout of the CB trunk.  I guess I am OCD about getting everything straight and vertical.  It was reassuring when the curvature off the plans matched the curvature of the template.  It's tough to do anything when the thermometer is below freezing every day.  

 

Happy sailing.  

[mattp]

Exciting day in boatbuilding at the greenhouse today. Lots of extra hands from holiday visitors helped us flip the hull so we can finish the bottom.

[mattp]

I fitted the centrecase by cutting a hole large enough to fit the case through then scribed with a pencil (which took about 30 secs), cut off the excess, and was ready to glue/glass it in. As you can see from the photo at this stage the seat uprights, keel batten and bottom stringers were all in place so the hull was very rigidly held. I'm sure the hull didn't move/shift or distort to any detectable extent. I'd do it the same way again. CheersPeter HK

I can now see how this method would save some serious time. Half of the cut is along the keel batten. There would no fine trimming of the bottom of the trunk necessary and finishing the open slot from the bottom would go faster because you could just plane it down to match the hull curve. However, the way according to plans wasn't particularly difficult or time consuming either.

[Scott Dunsworth]

It looks to me from the pictures that you have it as perfect as it comes,,,,,,,,,,, and no need to over think it!      

[mattp]

Wow, thanks Scott!

Quick update:

We sanded a radius on the chines, filled all holes, and tapped the seams.

We debated a little about whether to tape the center seam before keel, and whether to sheath the hull in fiberglass before or after keel install. Finally we decided that tape wasn't necessary under the keel but the fiberglass would be easier to flatten out, overlap, and adjust without the keel in place.