Question for the experts

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mtpocket
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Question for the experts

Post by mtpocket » Thu Jan 27, 2005 10:31 pm

I haven't worked on my Redbird since early December. The last thing I did was pull it off the stations and roll it over. I am ready to sand the inside, if I ever get the time.

Problem: I noticed that the hull has closed up some in respect to what it was while on the stations. I measured the 0 station and measured the hull across the sheer line and found a 3" differential. It springs back to normal width without much effort and more importantly without any pops or cracks. Thank God

Question: Since my outer stems extend about two inches above the sheer line, could I drill a hole in each of the stems, attach a line between them and draw them together, hence opening the hull back to it's rightful dimension? I understand that I will have to work around this line for a while, but I don't mind. Would I be causing a new, bigger, or worse problem? I believe that by prying the hull open with a piece of lumber would also work, but then I will have to remove it before I attach the inwales, which could significantly change their dimension and angles. It would also change the size of the decks. The extra length of stem will be cut off anyway. Thanks in advance

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Glen Smith
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Post by Glen Smith » Thu Jan 27, 2005 11:00 pm

For sure, you should try anything to get the hull back to its intended measurements. On one of mine, I just had to relocate a few of the hull cradles and it was fine.
Maybe using the excessive stems would work well. What you need to do is to respect the hull width and the rocker.

Good luck.

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canoebuildinggolfer
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Post by canoebuildinggolfer » Fri Jan 28, 2005 1:02 am

Hi MTP, What about cutting down the stations below the gunwales line, so you can work and put 2 stations back in either side of O with a brace between ? If you don't want to cut 'em make some 'new' ones....if you screw the brace in it shouldn't be too big a pain to work around....TC

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Todd Bradshaw
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Post by Todd Bradshaw » Fri Jan 28, 2005 2:34 am

While pulling the stemheads together may flare the midship sheerline width back to what it was, I have my doubts about it bringing the rest of the hull accurately back to where it's supposed to be. If you pick up an un-gunwaled, lightweight hull from some materials by the ends, the boat will actually fold in half across the middle. What you're proposing, while not as extreme, puts the same kind of force on the hull without duplicating the forces that the original forms put on it. Three or four temporary thwart-like cross-braces is probably a better idea. You can screw them in or cut notches in their ends which fit over the sheer line and hold them in with duct tape if needed. They can also help make the hull less floppy when you start working on the inside and can be removed and replaced as needed as you work on various areas.

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John Caldeira
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Post by John Caldeira » Fri Jan 28, 2005 6:57 am

When a hull is off the forms, I use spreader sticks to maintain the correct beam until both sides of a hull are fiberglassed. The sticks remain inside the hull until both sides are fiberglassed.

Ditto on the earlier reply that indicated that pulling the stems inward may have the undesired consequences of chaning rocker and widening the wrong part of the boat.

Of course, it is always good to keep the forms inside the hull as much as possible until both sides are fiberglassed.

John

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mtpocket
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Post by mtpocket » Fri Jan 28, 2005 9:00 am

Thanks for the help guys. I guess I will put all of the stations back in temperarily and make some spreader strips to match the hull width, then remove the stations. I can leave the strips on while I sand and fiberglass the inside.

Rocker? What rocker? The hull closed up enough that the rocker changed from 1.5" down to a measly .5". That is something I will have to pay very close attention to. Thanks Glen for pointing that out.

New question: With the inside fiberglassed, will the hull hold its shape any better? Will I have to reinstall the stations again in order to keep the correct width while attaching the gunwales and decks?

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Todd Bradshaw
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Post by Todd Bradshaw » Fri Jan 28, 2005 11:29 am

The inner glass is not likely to lock the boat into it's designed shape either, so don't throw away those spreader sticks. Installation of the gunwales (straight stock forced into a curve) will also want to narrow the boat at the sheer. This is perfectly normal and things won't be locked in place until the gunwales, thwarts and decks are all installed - at which time you'll see a vast change in hull stiffness. Just do what you can to keep the shape as close to what it's supposed to be as possible until the gunwale/thwart structure is added and you'll be fine. And be careful about supporting the hull carefully when moving it around while it's still in the unreinforced, floppy stage.

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mtpocket
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Post by mtpocket » Fri Jan 28, 2005 11:56 am

Thanks Todd,
With all the good information, I should be alright. There's so much to consider. I am ready to get back to work.

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