Getting ready to stitch Belhaven #21

[Larry Q]

My sides and bottoms are scarfed, epoxied on the inside (3 coats) and sanded. I still need to mount the stringers and finish the cradle, but I am now thinking through the stitching process. Of course, I have some questions ...

Is there any reason not to drill the stitch holes on the bottom seam before gluing the butterflies? I have to work outside once it is butterflied, so I want to get as much done as possible first.

Can I drill the stitch holes for the chine now if I am careful to measure along each of the curves? It seems to me that if I measure carefully it should all line up in the end.

I have seen pictures of reinforcing the butterfly with a piece of plywood screwed over it. Is this on the inside or outside? How long do you leave this on (I am thinking about not creating a flat spot there)?

Any helpful hints would be gladly accepted.

[Larry Q]

I knew there was another question rattling around in my brain:

Should I bevel the panels at the chine or just at the centerline?

[Scott Dunsworth]

Larry I can't remember if I predrilled all of my my panels. I believe I drilled the side panels stacked on top of each other. Then drilled the bottom keel line with the bottom panels stacked. But I think I drilled the chine holes in the bottom panel as I stitched the hull up.

Be sure to bevel your edges it will make fairing the hull much easier.

I reinforced the butter fly with a 4 inch strip of plywood back about 18 inchs. If I can fine a pic I will post it.

Scott

[Scott Dunsworth]

Also I removed the ply wood on the first picture before stitching. It was there to keep everything flat and tight till the butterfly cured. DO NOT try to stitch up untill that joint is very cured. I would also double fiber glass it. Mine was just starting to tear as I got the boat opened up.

I had four people helping me open her up and it was a job.

I also used saw horses as extra help.

Scott

[Tom Williams]

Hi Larry,

Here's what I did on my CS17:

- I layed the butterflys on top of each other and drilled the 1/8" stitch holes on just the centerline joint. I used 6" spacing and later on wished I had used 4" (You need to climb aboard to epoxy the CL).

- I predrilled the sides only at the chine. After folding, it's easy to eyeball the mate and drill a hole. The side and bottom wrap with slightly different curvatures so predilling both will develop an offset as you go back (I think anyway)

- Sandwich the butterfly between two pieces of plastic covered plywood (Packing tape works well) with glass on both inside and out. Don't worry about running screws through the hull pieces. Those small screw holes are easy to patch up later. Getting a good fitting, flat butterflys is key to a balanced hull. Make sure you shoot some dimensions at the aft end of the hull & make sure the starbord & port sides are the same. I would plan on leaving the flat Graham designed in with this method. I think it really makes the bow of the boat!

Good luck, Tom

[Scott Dunsworth]

One other thing Larry I think I would do what Tom said down the keel line. The boat will do everthing in its power to try to open up in the mid four or five foot of the center line. I didnt have any trouble along the chines though.

Scott

[Ken_Potts]

Larry,

I agree with everything Tom said (I think I used exactly the same drilling process too). I only want to add that I did the two flat joints for the butterfly (port and starboard) laid on top of one another to make sure that they were identical. Even if you do one joint and let it cure before doing the next joint you can use the first set as a template.

Also - I broke one of the sides when unfolding the boat. Some folks have used temporary reinforcements when unfolding the boat with good success, but even if you break the joint it can be fixed (it was a horrible noise when it went - A dark, dark moment indeed...)

[Larry Q]

You guys are great! Thanks for all the suggestions. I am hoping to get everything else out of the way evenings this week so I can go 3D this weekend.

I was planning on a couple of helpers. Sounds like I need more. The bottom panels are relatively stiff, but heavy and the sides are not too heavy but not stiff at all. Guess I would be better off with more hands than less.

Thanks again!

[Scott Dunsworth]

Larry I didnt have the stringers glued in yet when we opened mine up. That might help with the flopping around of the panels.

Ken brought up an important point that I forgot. Laying the butterfly panels on top of each other to make them identical.

It is nice having this forum to let everybody chime in.

Wish gas wasn't so high and if I wasn't trying to get mine on the trailer. I would drive out and help you. Also stop and see Travis's Princess.

Scott

[Kidd]

I wish this thread had been here when I built my CS 17 hull. I don't want to try to add to the wisdom expressed here except to reiterate the part about the middle four feet or so being the part which will not likely want to join together. Just make sure to have a camera handy when you open it up for the first time. It is the part I remember most about building Sunshine. It goes instantly from being a couple of pieces of plywood on the floor to something you can actually tell is going to be a boat.

[Tom Williams]

One last input on folding the boat. I had read cases of the plywood fracturing during the fold. To help prevent this, I sponged water on the forward panels where a lot of bending was going to occur. I sponged the water on only the outside where the panel was going to be in tension. After about 5 hours (water every 1/2 hour or so) the forward panel had warped partially into its bent shape.

I don't know if this helped but, the fold went well.

Tom