Author Topic: Mixed messages with stringers  (Read 217 times)

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Offline pyro225

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Mixed messages with stringers
« on: November 11, 2017, 10:07:54 AM »
Hi all - I know I do a lot of talking but the weather has been real bad for the last month so no further work has taken place...

However this week I went to my local mercury dealer to order the parts to fix up my outboard and I saw a lovely speed boat there with a black max on it and the guy tells me he rebuilt it a few years ago and he races it... anyway long story short he did the floor and transom but he didnít change the stringers he said the wood is only there to built the bridge the glass goes over and the strength is in the glass not the wood - he just put a few more layers on top of his old and the boat fine.

I then did some googling and there really seems to be mixed messages on this.. so Iím asking is there any truth to this?


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Offline Rich_V174SS

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  • 1967 V174 Crestflite SuperSport Modified
Re: Mixed messages with stringers
« Reply #1 on: November 11, 2017, 10:20:29 AM »
The answer on this is both yes and no. My take on it is there are two schools of thought here. It depends on how much fiber glass is used. In a lot of our Glastron boats the wood provides the structure and minimal glass is used to hold it together. In other boats I've seen there could theoretically be hollow cardboard forms used for stringers provided there's enough layered glass on top to create the rigid skeleton of the hull.
1967 V174 Crestflite SuperSport Modified
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1970 V176 Swinger
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Offline V153

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Re: Mixed messages with stringers
« Reply #2 on: November 11, 2017, 08:41:09 PM »
If I may. That stuff between the glass on your stringers and transom and floor? Is there for a reason. And it ain't just to hold the fiberglass in place.

The notion that whatever's encapsulated inside is sposed to be sacrificial is pure undiluted bs.
'81 Baja 15SS_140 Frankenrude_66.7 mph
'70 something SpeedCraft_(Allison 16R Clone)_Restoration In Progress


WALK TALL AND CARRY A BIG BILGE PUMP

Offline pyro225

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Re: Mixed messages with stringers
« Reply #3 on: November 12, 2017, 03:03:05 AM »
Fair enough I have also read that some new boats they are laying down foam (not composite) to wrap the glass around as well i imagine the whole boat would have to be designed with this in mind

Offline V153

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Re: Mixed messages with stringers
« Reply #4 on: November 13, 2017, 03:16:24 PM »
If it's not structural I guess it really doesn't matter what ya use as a form. As Rich mentioned I've seen cardboard, etc.

Personally I've used composite(s) on my last two rebuilds. Yeah I know it's a lil more expensive BUT. It'll never ever absorb water and/or rot. And you can tool it with a razor knife'n a piece'a sandpaper. Plus you don't have to seal it, or worry about whether the glass is gonna stick.
'81 Baja 15SS_140 Frankenrude_66.7 mph
'70 something SpeedCraft_(Allison 16R Clone)_Restoration In Progress


WALK TALL AND CARRY A BIG BILGE PUMP

Offline pyro225

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Re: Mixed messages with stringers
« Reply #5 on: November 14, 2017, 07:25:42 AM »
So bit of a crazy idea - could I pull out the old stringers by just cutting the tops off and pulling the wood out then pouring a load of resin in the Channel where the wood was?


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Online Hyperacme

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Re: Mixed messages with stringers
« Reply #6 on: November 14, 2017, 09:45:33 AM »
I've heard / read about foam used in core's of the decks and cabin roofs of large yacht's.
Even core's of hulls of yacht's, but they had problems with delamination.
It (foam or resin for stringers) might work, then again it might not ...
Best bet go with something you know will work.
Composite or wood ...
Gregg
'76 CV16

Offline dorelse

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Re: Mixed messages with stringers
« Reply #7 on: November 14, 2017, 11:18:02 AM »
You can't just dump resin in...you can't take shortcuts...do it the right way so you never have to do it again.  Lots of examples and methods for the right way, but none of them show pouring resin in.  There are however pourable transom & stringer products out there.  Seacast is one.  Just dumping resin in is not one of them.

This is why so many project boats wind up on CL, or being given away, the tear out is easy, the rebuilding is hard.

So bit of a crazy idea - could I pull out the old stringers by just cutting the tops off and pulling the wood out then pouring a load of resin in the Channel where the wood was?

1981 Metric C-512 "Barfly"

Offline Plugcheck

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Re: Mixed messages with stringers
« Reply #8 on: November 14, 2017, 12:06:09 PM »
Well stated Doran, resin simply has little strength that a wood stringer would have.  And as stated, do it right the first time, or plan to do it again down the road.
Michael
1979 CVZ-18 388 CI Vortec Mouse
1980 CVX-16SS 140 Mercruiser
1979 CVX-16 Johnson 175
2002 Bennington 2275CC 90 Mercury
1985 Intimidator project, gps 85 mph (on trailer)
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Offline V153

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Re: Mixed messages with stringers
« Reply #9 on: November 14, 2017, 04:47:48 PM »
No reason not to use the hollow stringers as forms. But as stated above use a pourable 'ceramic' transom compound a la SeaCast. We used an Arjay equivalent. (Cheaper.) Do NOT use resin.
'81 Baja 15SS_140 Frankenrude_66.7 mph
'70 something SpeedCraft_(Allison 16R Clone)_Restoration In Progress


WALK TALL AND CARRY A BIG BILGE PUMP