[C38] Cracks by Stem Fitting

[Charles Finn]

Ray,
It actually is quite common for the gelcoat to crack with no structural 
problems.  Gelcoat is very brittle, while laid up glass has a much 
greater modulus of elasticity (one of reasons it works so well in 
boatbuilding).

Chuck Finn
Mighty Quinn #114
Great Lakes


On 9/6/2013 12:35 PM, Ray Torok wrote:
> Thanks Chuck,
>
> I see no evidence of cracking inside the hull, so there is hope. 
>  However, it's hard to understand how the glass up there can move 
> enough to crack on the outside, without the crack extending into the 
> glass.  You're right.  I need to get out the grinder.
>
>
>
> On Fri, Sep 6, 2013 at 9:30 AM, Charles Finn <charles at finn.ws 
> <mailto:charles at finn.ws>> wrote:
>
>     Ray,
>     Obviously there is more to this as you just did some kind of
>     repair for some reason.  The best way to find if there is a
>     problem is to discover whether the cracks are superficial or
>     structural.  Take a small grinder, mototool, or even a screw
>     driver and gouge the gelcoat out of the cracks.  IF the crack does
>     not extend into the glass, you fix the gelcoat and call it a day. 
>     IF the crack extends into the glass, then you have a structural
>     repair which will require you to first cut out and then rebuild.  
>     Here is hoping this is superficial!
>
>     Chuck Finn
>     Mighty Quinn  #114
>     Great Lakes
>
>
>     On 9/6/2013 12:21 PM, Ray Torok wrote:
>>     Hi Steve,
>>
>>     I have a backstay tensioner, but it's only on when we're sailing.
>>      When the boat's at the dock, the backstay is left on just enough
>>     to keep the headstay from flopping around.
>>
>>     Latest theory is that when I replaced the two bolts that anchor
>>     the stem fitting to the deck (a few weeks ago), there was enough
>>     slop in the bolt holes that when the headstay was tensioned, the
>>     fiberglass in the deck was loaded in compression until the stem
>>     fitting moved back just a little to where the two bolts and the
>>     stainless stem fitting picked up the load again. If that's what
>>     happened, the cracking in the fiberglass shouldn't get any worse.
>>      Does that sound believable?
>>
>>     Thanks,
>>
>>     Ray
>>
>>
>>     On Thu, Sep 5, 2013 at 10:48 PM, Steve Smolinske
>>     <SSmolinske at rainierrubber.com
>>     <mailto:SSmolinske at rainierrubber.com>> wrote:
>>
>>         Ray,
>>
>>         Do you have a backstay tensioner that is left on?
>>
>>         *From:*listserve-bounces at catalina38.org
>>         <mailto:listserve-bounces at catalina38.org>
>>         [mailto:listserve-bounces at catalina38.org
>>         <mailto:listserve-bounces at catalina38.org>] *On Behalf Of *Ray
>>         Torok
>>         *Sent:* Thursday, September 05, 2013 5:56 PM
>>         *To:* Catalina 38 Listserve
>>         *Subject:* [C38] Cracks by Stem Fitting
>>
>>         Esteemed C38 Gurus:
>>
>>         Hoping you can help advise on my latest old boat issue.
>>
>>         I have some cracks showing up (and growing) on the outside of
>>         the hull in the few inches between the ends of the toe rails
>>         and the headstay stem fitting.  The cracks are horizontal and
>>         about 3 inches long. On one side the crack is about 1 inch
>>         below the deck.  On the other it is right at the edge of the
>>         deck.
>>
>>         It appears that the headstay load is pulling the bow upward,
>>         and the last few inches of the bow doesn't have the toe rail
>>         and bolted hull-to-deck joint of the rest of the boat, so
>>         it's bending a bit and the fiberglass is cracking. On the
>>         inside, the heavy stainless backing plate for the strap
>>         running down the stem also stops several inches short of the
>>         bow, and that may be a contributing factor.
>>
>>         I'm wondering if this is a problem with the early boats (mine
>>         is hull #37) that they fixed at some point. Any thoughts on
>>         known or proposed fixes would be appreciated.
>>
>>         Thanks much,
>>
>>         Ray Torok
>>
>>         THIRA
>>
>>
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>>
>>
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