To Glue or not to Glue

[street hawk]

Hi Boys and girls,
im very much a newbie to boat building so please go easy on me,
"long time listener first time caller"

ok so I purchased a project boat, yippee,
unfortunately its been another mans project before me so thus far I have spent undoing his incorrect repairs (uncured epoxy etc)

a very basic question needing a very defined answer,
so work so far

I have cleaned out the fiber glass hull (its a 11ft ski boat)
removed the rotten stringers (partially rebuilt) and cleaned the glass,
I now have some brand new redwood stringers to install.

so my question here is, do I glue them down to the glass hull, before running
my new fiber glass over, or is the idea here that the fiber glass holds them in place?

may seem a silly question, but am yet to find the answer? previously the stringers had been removed and re epoxy's (as mentioned uncured)
so no Idea how there were previously attached.

your help is greatly appreciated

[daiquiri]

Stringers are basically reinforcing bars subject to bending moments. The wood can either take all the bending loads (when, say, chopped-strand glassing over serves just as waterproofing), or can serve as a core for a more resistant mat, cloth or roving laminate over the wood (in which case the laminate takes most of the load).
In both cases the wood has to be tightly glued to the glass skin, in order to permit a correct transfer of the loads, to avoid the abrasive movements between the wood and the laminate skin and also to seal longitudinal waterways between the wood and the laminate, which can cause wood rotting.
Cheers!

[street hawk]

fantastic, thanks for the response,

in that case, what are my best options for glue? ill be using epoxy west system, for the glassing.

[daiquiri]

Then epoxy will be the glue.
Lightly sand the wood to remove any stains, dirt etc. from the surface and to create a grip for the epoxy, thoroughly wipe off the sanding dust and then apply the resin according to West System specifications.
Don't forget to round off sharp corners at the top of the stringers, and to fill and round the bottom ones (where they meet the hull), to allow the glass skin to gently wrap around them. You can use epoxy additivated with silica, limestone or even sanded wood dust as a filler, or some specific West System filler product.
Make sure that the moisture content of the wood is less than 15% (ideally 12%) before applying epoxy.
Cheers!

[street hawk]

ha ha fair call, more along the lines, a 2pac epoxy in a dual tube / or the powder mixes? any good brands you could suggest ?

much appreciated

[Landlubber]

Try AA Fibreglass (For your epoxy)....

[daiquiri]

Originally Posted by street hawk

ha ha fair call, more along the lines, a 2pac epoxy in a dual tube / or the powder mixes? any good brands you could suggest ?

West System is an excellent brand, you can stick to it if the price tag is ok for you. Contact your local dealer and don't be shy. Ask him everything you need to know about products they suggest for your specific needs.

Here in Italy we have another very good and widely used brand, Checchi (http://www.cecchi.it/italiano/english.html), and I tend to use their products. C-Systems 10-10 and C-Systems 10-10 CFS epoxy come with a variety of additives for any boat building, repairing or maintainance task.

But you're in New Zealand and I'm in Italy - so both West System and C-Systems resins are import products in your country. I believe you should be able to find an equaly good local product, which will deliver the same quality for less money.

Cheers!

[street hawk]

sounds great thanks for the help !!