Stringers !! everyones favorite subject

[RobF]

Where's the reference to stringers which this post is all about ?? If you not interested stay in your box !!

pretty sure he was on your side lol

!!!!!!!!!!!!!!!!!!!!!!!!!

[XstreamVking]

This is not a post, it's a lecture!!!!!!!!!!!!

[tunnels]

And that's my point, which you seem to have missed - our boats were built with a single reinforcement that serves both purposes.

Stringers are stringers and girders are girders stringers in most cases are there to strengthen the hull or where ever they are fitted!!
Girders are beams the have no give are ridged along the hull and used for carry weight, floors ,inboard motors, fuel tanks etc etc .
Because of the ridged strength of a girder the laminate for the hull needs to be designed differently to cope with the panel bending each side of the girder so its transferred and distributed over a bigger wider area ! Pads of glass need to be made for the girder to be sat onto so the panel loads and bending forces are distributed over a bigger area.
Shock loads are the ones the do the most damage and can be seen along the bottoms of hulls that have fiberglass grids as the grid is a girder system not a stringer system and so different glass needs to be used in its hull construction .
A stringer system laminate uses different glass in a different way as the whole of a panel could bend from chine to keel ,transom to bow Plus its why cores are used to add ridged strength plus a stringer along the top !
There's more to all this than first meets the eye and production boats changing from A stringer system to the grid get caught if they done change there laminating schedule !!, first micro cracking appears from about half way to the rear where the grid is located inside the hull then the micro cracks gradually gets more noticeable as the boats get older !!
My old 1975 hull had a fibreglass grid and the hull was constructed with csm and woven roving only !! woven is the worst glass of them all as it has very little ridged strength than almost any other glass weight for weight !

[tunnels]

This is not a post, it's a lecture!!!!!!!!!!!!

If its a lecture then sit up and pay attention and stop arguing with everything !!.Exams end of there year so do your home work !!

[kelvin523]

This is awesome in a completely irrelevant context and for entertainment purpose only. I'm on the side of DARPA and Chicago University both of which capt.insignificant.com explained, in not so scientific terms, has no relevance to stringers and modeled body construction.

[tunnels]

This is awesome in a completely irrelevant context and for entertainment purpose only. I'm on the side of DARPA and Chicago University both of which capt.insignificant.com explained, in not so scientific terms, has no relevance to stringers and modeled body construction.

Ummm dunno ???

[kelvin523]

This thread still sucks...

[tunnels]

Something that has never had a mention or been discussed is the shape of stringers !!
Skinny stringers like ply wood on edge exerts a tremendous localised pressure over a very small narrow area !!
Even mounted on top of core this pressure is capable of bending the panel quite significantly !!
If there is no core on to a solid glass hull then the bending of the hull panels is really significant !!
This shows up with boats fitted with grids where the Actual lay up of the hull has not been changed to anticipate the hard pressure points and micro cracking of the gel coat begins to appear as the boat ages and gets used more !
To anticipate this bending and to spread the load out wider then a glass pad needs to be made by laying strips of glass !! NOT just any old glass but a decent fabric with glass strands going it the right direction to spread the loads better also that is going to add strength and flexibility yet become stiff enough to distribute the loads imposed outwards ! 1708 is possible the best fabric available and a minimum of 2 layers with staggered edges so there are no hard points and is tapered where the layers finish ! the actual glassing of the stringer to the hull is going to add even more to this pad as well .

Ok that's narrow stringers !! How about making wider stringers !! These can be made from Foam !!
foam has been used for longer that I can remember !! Easy to work with !, easy to lay , easy to shape ! and wont rot ,wont fall over when extreme pressure is applied get covered 100% with glass and because they are wide distribute and spread the loading over a much wider area

The glass use over the foam is what's going to do all the work !! There is a natural force upwards from the hull when pressure is applied so the glass layers need to be able to carry this pushing load without buckling or compressing and deforming in any way
so again any old glass is not good enough
Triaxle is the best I know of BUT when you lay it there's ways of making an even significantly better stringer !! ok lets look at what's been written !!
First layer , this is against the foam -45/45/90 ,second layer 90/45/45 !! now you see the 90 degree vertical strands are buried and encased between layers of 45 stands both sides so the bulk of the load is taken by the vertical 90 stands which are impossible to bend in any direction and the loads imposed are all carried and spread out onto the hull bottom !

[tunnels]

[QUOTE=vnemous;2987462]yo north korea is a bunch of scum bags or haven't you heard[/QUOTE
Here I get news you probably never even see I been following the lovely little fat man since day one !! He's one very clever cookie!

[powerabout]

so can we make stringers that also hold the floor up?
what would be different from separate stringers and girders?

[Mark Poole ModVP]

Grids are a great idea. The weakness can be how and what they are bonded in with. Use the wrong adhesive and now the whole grid will eventually separate from the hull and possibly the liner too.

[tunnels]

so can we make stringers that also hold the floor up?
what would be different from separate stringers and girders?

it depends the size and weight of the floor for a start !! Bracing can be attached to the underside of the floor and not touch the stringers at all so they are completely independent of each other ! A proper cored/ glass floor with bracing attached underneath would definitely be my choice ! so what if the floor has a little movement

[powerabout]

it depends the size and weight of the floor for a start !! Bracing can be attached to the underside of the floor and not touch the stringers at all so they are completely independent of each other ! A proper cored/ glass floor with bracing attached underneath would definitely be my choice ! so what if the floor has a little movement

Soft floor is nice to walk on yes but how much weight is gained by not having them linked together which seems a simple way to get a more rigid hull with less weight?

[tunnels]

Soft floor is nice to walk on yes but how much weight is gained by not having them linked together which seems a simple way to get a more rigid hull with less weight?

Like all things the choice is yours !!
stringers are to strengthen the hull only !!
girders are load carrying and have very little to no flex or movement .
the under floor supports can be in the form of foam shapes glassed over and the stringers to do there own thing and should not be attached to the floor in any way !

A honey comb composite floor is way lighter than a plywood floor even if it 1/2 thick ply !
AND THE COMPOSIT FLOOR SHOULD NEVER GAIN ANY WEIGHT OVER TIME FROM GETTING WATER LOGGED

[powerabout]

Like all things the choice is yours !!
stringers are to strengthen the hull only !!
girders are load carrying and have very little to no flex or movement .
the under floor supports can be in the form of foam shapes glassed over and the stringers to do there own thing and should not be attached to the floor in any way !

A honey comb composite floor is way lighter than a plywood floor even if it 1/2 thick ply !
AND THE COMPOSIT FLOOR SHOULD NEVER GAIN ANY WEIGHT OVER TIME FROM GETTING WATER LOGGED

so in rough water the floor will be banging on its supports as they are not attached?