Broken Butterfly

[Tim]

This weekend I attached the sides to the bottom and stitched the bottom halves down the middle. It's a quick job; the only problem is that when your done there's not much to do but wait for epoxy to cure and I wanted to finish stitching and gluing this weekend.

So I waited until the glue on the tape was about 80% set then opened the butterfly. It's a little awkward trying to control the long pieces by yourself but the tape seams made it. Once I got the bulkheads in place and starting bringing the beautiful bow together that's when I broke the butterfly at the newly taped seams between bottom and sides.

I took off the sides and worked and stitched the bottom into place all around then stitched on the top pieces. Theres a little gap at the front bulkhead but I think it will all work out with filler glue and tape. It would have been definitely easier to do it the right way; I really had to work to the top sides pulled in at the bow.

I took some photos but it looks like CS17 number 86 has been through a war with all the extra stitches and splints. Reminds me of the time my Dad hit a Monarch and we taped its broken wing back together.

[Roger Peterson]

Hi Tim,

I had the same problems with my CS #58 but I fixed the seam as well. You are right, the whole assembly is kind of floppy to get together single handed. I tried wrapping a line around the hull to act as a second "hand" to help hold the hull together while I wired the sides to the bottom. It worked pretty well until I over tightened the line and ripped the plywood down the side of the hull. I was really embarrassed by my lack of foresight. I should of clamped a support to the edge to protect it from the point contact of the line. Anyway, I learned how to repair a tear in plywood and now the hull is "good as new". It seems like almost every time I work on the boat. I learn a new skill.

Roger

[Wade]

OK, y'all have got me scared now! :shock:

Guess the solution is to have a 3D party.

[Brent]

What weight of cloth was used to hold at the side/bottom butterfly joins? Just curious, wondering if heavier cloth or multiple layers would help.

[Roger Peterson]

What weight of cloth was used to hold at the side/bottom butterfly joins?

I used 9oz tape and let it cure 24 hours BUT it had been raining and there was a light mist in the air. I was excited and in to much of a hurry and should have waited another day or two just to make sure.

The tape started to tear and then just let go. :oops: My Fault. Like I said in my previous post, I am learning something new every time I work on the boat. (lots'a repair techniques) :wink:

Roger

[Designer]

Tim,

I'm sorry that you had trouble with going 3D. There have been too many of these boats built for the method not to be valid. Normally we don't have trouble folding a boat up, but occasionally it happens. The reasons are many fold. Plywood's resistance to bending can differ from sheet to sheet, the epoxy not being fully cured (as you mentioned) and rough handling, which is hard to avoid while working alone.

On our CD we covered that problem with this picture and text. Perhaps it was too subtle for you to have caught?

Usually if a problem is going to occur, you will notice some whitening of the glass especially at the aft end and at the seam. If you screw through a pad of 3/8" plywood from the outside to a similar pad on the inside, you will take the load off of the glass tape and you should have no further problems.

The advantages of this method are many, beside being quicker you usually end up with a prettier bow.

I had to down size this picture to fit on the forum so I hope that it is clear.

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[Tim]

I never meant to imply the there was any problem with the design or methods. I have varied from them to try to same time or cost so my extra trouble was my own fault. I think it will be ok -see photo below. I too used the blocks (not shown in the photo) and many extra wire ties but only after things fell apart. Even if you mess up there are ways to correct it.

Right now I'm taking a long look to see if there is anything I want to change before gluing. Plus its too cold outside again.

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[mustangermatt]

I had a little bit of a similar problem, except the 3/8 to 1/4 bottom joint started to tear on the outside edge. This was caused I think by a combination of fir ply which is less flexible than the okoume, and I had extended the bow tape back 14 inches. I doubled the glass on all the joints and everything has gone together great since.

The lesson learned? Lots of help and take my time. People love to come over and help with things like going 3d, flipping the boat etc. Just don't ask them to sand anything :-)

I also have a chair in the shop in front of the heater where I sit and just dream. I usually wind up falling asleep in that chair, which is just the kind of relaxation I need after a day at the office.

Now this is why I am building a boat :-)