Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors
Old 02-20-2008, 03:22 PM
mongo75's Avatar
mongo75 mongo75 is offline
Senior Member
Join Date: Aug 2007
Rep: 95 Posts: 262
Location: Orange County California
Another stringer replacement question

I'm doing a total restore on a 1968 Luhrs 25' Flybridge. It has 4 stringers, with the two center stringers supporting the engine/velvet drive/ v-drive. I need to replace the two center stringers because (a) the company that bought out Luhrs in the 60's did crappy glass jobs in the bilge by not glassing the limber holes and (b) somewhere along the line some dummy cut into the stringers to mount an engine (?) and neglected to cover his work, so they are shot.

My question is, can I take them both out at the same time while the hull is on the trailer, and will the 4 bunks and two remaining outside stringers support it, or do I have to do one at a time? I can't do it on a cradle as much as I'd like to. Also I need to get an exact 25" between the two new stringers so that's why I'd like to do them at the same time- I can pre-make them (laminate 2 pieces of 3/4" ply w/matt in between them, glass 2 layers of 18oz roven and one of 1708 over that) and then bed them to the hull in a jig that keeps them centered and parallel to eachother.

Thanks !!!!!
Attached Thumbnails
Another stringer replacement question-pre-20clean-20stringer.jpg  Another stringer replacement question-112506.jpg  Another stringer replacement question-112507.jpg  

Reply With Quote
Old 02-20-2008, 10:08 PM
rotfix rotfix is offline
Junior Member
Join Date: Oct 2007
Rep: 10 Posts: 19
Location: austin
i'm no engineer but in my boat looks similar to yours, 23' w/all of the stringers out...the hull didn't flex that much compared to only 1 side out. a good fitting trailer is important. i don't think in the 20-30 mph range, there will be any adverse affects.

rather than worrying about it, can you form the stringers and then make a jig that works off an existing stringer? that can be helpful to maintain previous deck height...
Reply With Quote
Old 02-21-2008, 07:24 AM
PAR's Avatar
PAR PAR is offline
Yacht Designer/Builder
Join Date: Nov 2003
Rep: 3839 Posts: 16,324
Location: Eustis, FL
Danny, the hull shell laminate on your old Luhrs is more then stout enough to permit you to remove both stringers. Unless you're a particularly well fed person and the hull distorts under your weight as you work, don't worry about it. If you haven't missed too many meals and the boat does move a bit, then add some additional support on the exterior of the hull, like jack stands, blocks of wood with shims, etc. to get the hull solidly fixed (support the trailer too, so the springs don't come to play)

I mention this because you can shape the crap out of some stringers, while you're in the boat, just to climb out and have the distortion go away, making your nice fitting stringers a poor fit.
Reply With Quote
Old 02-21-2008, 09:47 AM
the1much's Avatar
the1much the1much is offline
hippie dreams
Join Date: Jul 2007
Rep: 696 Posts: 3,909
Location: maine
run a cross brace about a foot from ya transom,,then another across about 5 or so feet forward the start of the stringers,,,if room permits 1 running diag. from 1 corner of your cross brace to the opposite corner of the other cross brace. with all that even if a "fluffy" person gets in or leans on it from the outside , everything should be o.k. ,,,that said,,,,everything "should" be o.k without any bracing,,,but 3 or 4 2x4's is cheap ease of mind heh
hehe ,,,,,Jim------>
Reply With Quote

Old 02-21-2008, 12:51 PM
mongo75's Avatar
mongo75 mongo75 is offline
Senior Member
Join Date: Aug 2007
Rep: 95 Posts: 262
Location: Orange County California
Thanks for the reassuring replies everyone- these pics are kinda old- since taking these a few months ago I've added the gunwales to the sides up to the v-berth bulkhead, and they have a 7' opening between them, so they are between 14 and 17" wide, so that adds a lot of supprt to keep the hull from flexing.

I think I will make a jig that ties in the two outside stringers and forces the two inside ones to be dead on. Phew- one less headache to ponder over!
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Ski Boat Stringer/Sole Replacement rickr Fiberglass and Composite Boat Building 40 06-21-2008
05:09 PM 
79 Ski Supreme Restoration and Stringer Replacement TStoney Boat Design 0 10-27-2006
02:30 AM 
Partial stringer replacement questions BMerriman Fiberglass and Composite Boat Building 4 10-07-2006
02:53 PM 
floor and stringer replacement man5 Fiberglass and Composite Boat Building 12 08-30-2006
10:00 PM 
what to use for FLoor and stringer replacement jalbee Materials 2 08-19-2006
12:15 PM 

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.

All times are GMT -4. The time now is 04:07 PM.

Powered by: vBulletin Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2015 Boat Design Net