stringer bonding?

66mstgfsbk

Petty Officer 3rd Class
Joined
Feb 3, 2009
Messages
97
i have to replace my engine stringers and was wondering if i have to bed them in? if so what can i use? i was told they have to be bedded, but when i removed them there was nothing there just the hull. they were nailed together and glassed over. i almost forgot the boat is a 84 malibu ski boat. thanks for any help.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: stringer bonding?

yes you do......abd just about anything will do....pl 9000 or search peanut butter....

you just need somthing to keep the stringer off the hull a wee bit.....

this is to avoid a "hard joint"
 

66mstgfsbk

Petty Officer 3rd Class
Joined
Feb 3, 2009
Messages
97
Re: stringer bonding?

when i removed them there was nothing underneath just the fiberglass hull material. if they need to be bedded why would the factory just put them in and not bed them? thanks
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: stringer bonding?

because they messed up !

even a production line has new people on it. or less detail than we are willing to accept !

you need to bed the stringers or you will get a hard joint and the gell coat/glass will crack
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: stringer bonding?

after re reading this.....i can guess your question is that you want to understand......

ok

when a hull is pounded on by water......the force of the water beating on the hull is dispersed by the hull it self ....... with out stringers .....the hull will flex with the force of the water...whatever the direction of the force....(waves)....are you following me ?....(this is assuming a plaining hull at higher speeds than a displacerment hull)....this will wreak havoc on slightly larger hulls.....(over 14 feet)....as the distortion of the hull wanting to go one way and the force of the water wanting it to go the other, will crack the gelllcoat and the hull in a short time.


so....in a boat with stringers......if the stringers are not in contact with the hull....(a hollow spot).....the hull will flex too much (in that spot) for the gell coat and the glass to handle.....resulting in "stress cracks"....called crazing......normally this kind of crazing is right thru the gellcoat and into the fiberglass.

if the stringers are directally on the hull.......the hull will flex more than the rigidity of the stringers......resulting im more crazing or even a thru hull penetration......see bainy g's thread.

if the stringers are supported slightly away from the hull....the force of impact is dispersed thru the substance between the sharp edege of the stringer and the fiberglass hull......so the force of impact is displaced by the bedding compound. (what ever that may be)

i know this seems kinda complicated.........but all you really need to know....is shim the stringers and put something between them and the hull......peanut butter.....pl900.....or some other extra semi rigid (or rigid) water tight compound

im about to get killed by my bros here soon.......sooooo.
i hope that helps.

cheers
oops
 

66mstgfsbk

Petty Officer 3rd Class
Joined
Feb 3, 2009
Messages
97
Re: stringer bonding?

thanks oops thats the answers that i was fishing for. just didnt know why it had to be done. thanks again for the help
 

erikgreen

Captain
Joined
Jan 8, 2007
Messages
3,105
Re: stringer bonding?

yes you do......abd just about anything will do....pl 9000 or search peanut butter....

you just need somthing to keep the stringer off the hull a wee bit.....

this is to avoid a "hard joint"

Now now, you're not being honest. We all know you bond with your stringers (and the rest of your boat) by sharing Coronas.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,065
Re: stringer bonding?

Now now, you're not being honest. We all know you bond with your stringers (and the rest of your boat) by sharing Coronas.

Don't forget the lime! :p
 
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