Author Topic: extending boat length  (Read 6915 times)

Offline gakonasteff

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extending boat length
« on: April 30, 2008, 02:18:43 PM »
 trying to decide if I can extend the length of my widebody(around 8" )....I left the stringers, shelves and bottom long...do I just extend each part the same distance or is there a formula?
Steffan
Gakona,Alaska

Offline tolman_paul

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Re: extending boat length
« Reply #1 on: April 30, 2008, 04:39:41 PM »
It's pretty easy to extend it ~16", just use 3 full sheets of ply for the sides, and stretch the stringers, bottom panels and shelves to match.  I'd say why not stretch it as much as the materials allow.

Offline luk diver

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Re: extending boat length
« Reply #2 on: April 30, 2008, 08:23:15 PM »
Extend early and often (spoken as the first to stretch the 22 Jumbo to 23-7). IFF extending bottom panels you're better off adding on as far forward of the transom as possible IMO. We added short section near transom :'( and luckily after reading someone's similiar scenario with another design we checked closely and sure as heck had introduced a 'hollow' >:( immediately before the transom and this was 'death' for performance. Luckily able to do a serious amount of fairing with micro-ballons and got a pretty smooth bottom. WHEW. The fishdeck you gain extending is definetly worth the effort. Bob

Offline kiwi les

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Re: extending boat length
« Reply #3 on: May 02, 2008, 08:43:09 PM »
No problem - go further than that if you can. Make sure though, that when set up the transom mold, move IT back the apropriate didtance, or you will get into a little bit of strife. When I did mine, I also , because I had it on hand, used an alloy box section along the keel to keep it straight.
When others have put on the chine flats, they used dowls, screws, wired it up, allsorts - lots of hassels! All I did was to plane a 45deg bevel upper most,on the iside edge, put lots of mdf slats across the hull, gently screwing down with a piece of cellotape where it meets the hull, then clamped the chine flats to it. Mine were quite straight, but you could clamp a long straight edge allong the flats just to make sure. When I was satisfied with the fit, I mixed up a soft glue mixture, and trowed it into the 45deg! No mess, no hassels, easy peasy! When cured, ie the next day, I removed the mdf cross members, rounded off the inside hard corner, filled any holes that were missed, and glassed up.

les

Offline gakonasteff

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Re: extending boat length
« Reply #4 on: May 09, 2008, 09:43:10 PM »
thanks for the great info, i just finished scarfing (no glas yet) the 3/8" side panels and now have two 32" x 11'9 3/8" panels and two 4' x 11'9 3/8"....will I  still be able to extend 8"??   i just want it to be a full 22"
Steffan
Gakona,Alaska

Offline chuck9982

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Re: extending boat length
« Reply #5 on: July 01, 2008, 02:21:20 PM »
I streched as long as my bottom would let me I should be 25 ft and some change when complete.
Pizza Chuck
Graham, WA
Building J25.2
Started 3/2008
Got wet 7/2008 Cape Cod Bay
Got wet 2009 Charleston, SC
 & Lake Erie.
Got wet 2010 Some Kansas Lakes
Got wet 2011 Texas lakes and the Gulf of Mexico.
Got wet 2012 in Puget Sound.
2014 mothballed…..
2022 beginning the resurrection

Offline sinned

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Re: extending boat length
« Reply #6 on: July 02, 2008, 11:53:52 AM »
When others have put on the chine flats, they used dowls, screws, wired it up, allsorts - lots of hassels! All I did was to plane a 45deg bevel upper most,on the iside edge, put lots of mdf slats across the hull, gently screwing down with a piece of cellotape where it meets the hull, then clamped the chine flats to it.

les- any pictures of this during construction? dennis

Offline kiwi les

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Re: extending boat length
« Reply #7 on: July 02, 2008, 08:59:47 PM »
Sorry Dennis, not this bit. Hope my simple expanation helps. Just a quick note here. The chine flats had a 45deg bevel planed on, so that when clamped to the mdf, the open side of the bevel is looking at you. The celotape is used so that when a soft epoxy mix is forced into the bevel, it will go under the mdf, and not stick up. Make sure that you do not screw down the mdf to hard or the ends will bow up. It needs just enough pressure to hold in place. Also, clamp a straight edge on the underside of the chine flat

les