Stress crack questions (T-decks)

[cdnguitarsnboats]

I hear a lot of mention made on this board about stress cracks.
I have an idea of what a stress crack is, but I was wondering what types of stress cracks are the ones that keep you up at night.
Specifically, I'm interested in a late 70's Hondo t-deck and was wondering what I should be looking for. I know there are some cracks around the deck in front of the passenger seat, and in the rear deck around the splash shield.
To me, these don't seem to be a big deal. So my big question is what areas are prone to cracking on t-decks, and what would be considered a deal breaker?
Thanks for your help guys,
Jim

[Morg]

The cracks in areas where you mentiond are very common. You will also see some in the floor.
This is my opiniun, & being I can't reall y spell to when, take from it what you will.
Essentialy as you may know fiberglass resin never stops hardening. The amount of cracks in a boat are usually caused by these factors,
-Normal use. Its just gonna happen & if it never deos that can be a sign if other problems. Like the boat being to rigid.
-Areas of thicker gell coat. When laying up a boat areas that get a build up of thicker gell will eventualy crack.
-Abuse. Everyone drive a boat different. Some only go out in glass. Some run accross the tops of rollers like they are riding a dirt bike through a whoop field. The way the boat is treated will show.
Look at the overall amount of stress cracks. Pay close attention to around the stringers. Look for cracks around the prop. strut area.
Essentialy everything has a life span. You can see the amount of life a boat has been through.
But if you are from nor-cal it don't matter. You will probably sell it after a season or 2.
Morg

[mfrey]

I'm starting to believe they'll crack from being driven down the road on the trailer too. The deck on my old Sanger hydro flexes like crazy when being trailered...I noticed it while riding in it to the launch ramp at the races. Also when it shifts forward on the trailer, the bow eye/pin gets stuck and it "pulls" the bow down...now I'm seeing stress cracks in the bow area too. Very frustrating.

[Morg]

I'm starting to believe they'll crack from being driven down the road on the trailer too. The deck on my old Sanger hydro flexes like crazy when being trailered...I noticed it while riding in it to the launch ramp at the races. Also when it shifts forward on the trailer, the bow eye/pin gets stuck and it "pulls" the bow down...now I'm seeing stress cracks in the bow area too. Very frustrating.
Forgot about that. If a trailer is not set up right. They will get more abuse going down the road than on the water.

[cdnguitarsnboats]

Thanks for the replies, guys.
I liked your dirtbike analogy, Morg. I always wonder about the shots I see of people pulling wheelies and launching their boats for air time. Cool picture, but ouch.
Anyway, I've never seen a performance vehicle of any kind with fiberglass that didn't have stress cracks of one sort or another, so I always wondered what the big deal was.
As for longevity, my view is that any problem areas can be reinforced when time comes to redo the boat. Cause let's face it, they'll always need to be redone at some point. Have epoxy, will travel.
Concerning the Norcal thing, two seasons seems to be the extreme limit now. That Mouzer dude has taken it to a whole new level. Must be trying to have the local DMV named after him, or something.
Jim

[ACCEPTENCE]

I liked your dirtbike analogy, Morg. I always wonder about the shots I see of people pulling wheelies and launching their boats for air time. Cool picture, but ouch.
"Air Time" is alot of fun but it's expensive too.
...and your right!!! It's hard on the boat :hammer2:
Cheers

[bigkatboat]

Many of the builders in the past did not "plan" for their boats to last for 15/20/30 years. Many times the deck has not been 'held up' structurally, for long term/ hard use. Many builders just wanted to build a "nice safe, light boat". Look at many of the flatbottoms in use today, most just have a 'toe board' and little else to "hold the deck up". Some circle boat designs use a 'bulkhead' along both gunnels to hold up the deck and give more strength to the hull bottom. If you put a vertical bulkhead at each end of your fuel tank (running front to back). You could then repair the cracks at both ends of the cockpit and not worry about them coming back. The weight of the (unsupported) deck gets pounded and it has nothing holding it up, so it cracks in the closest thin spot to the deck weight. Back in the day, it was all about 'looks' and 'lightweight'. Also, those cracks won't make the boat any faster/ slower, nor will it "fall apart". Those cracks are "tatoos" of all the fun times your boat has seen!

[cdnguitarsnboats]

Thanks for all the good info, Bigkat. My concerns weren't so much an issue of the boat being faster or slower, but more about whether they could fail catastrophically and blow a side out, or something along those lines.
Reinforcement by adding a bulkhead or two sounds like a good idea, and I even have some extra carbon fibre panels left over from my inboard hydro project. Some extra weight doesn't mean anything to me, so I'll start thinking along these lines. Again, thanks!
Jim
PS. ACCEPTANCE - you're the main guy I was thinking of. If I'm ever out in CA again, I want a ride. You might want to submit a proposal to the IOC for a new Olympic sport. Wear a beach volleyball outfit and you'll be a shoe-in.