Buying a boat with prior keel damage?

[alaskaflyfish]

I doubt that the keel bolts have been hardened to the point of being brittle like some specialty aerospace components. More than likely they they are an alloy developed for toughness, durability, (modulus of elasticity) and corrosion resistance. So, slight bending and cold straightening should not reduce their strength or induce surface micro cracking. But again, Check the grade and alloy of the bolt to be sure. Defiantly refer to Catalina for advice on this matter with pictures and the estimated degrees of bend. They should be able to tell you with confidence.

[Singularity]

Originally Posted by Tspringer

The seemingly never ending search for a good boat I can afford continues...

Unless Catalina's rep provided the inspection after damage, prescribed the remedy, and signed off the repair I wouldn't buy the boat if there were any other options on the market. I'm sure I'm not alone, thus resale will be a problem if/when you go to sell the boat (if you bought it). Even if Catalina did hand-hold during the repair, still the resale should take a very serious hit.

Originally Posted by roverhi

Matt is an important part of a layup. It fills in the voids between the weave of the cloth reducing the resin rich layup that you get using just cloth. It also provides separation between the layers of cloth/roving so they get an 'I' beam effect which makes for a stiffer layup.

Can you site any studies or texts to support this idea? I understand what you mean, and it's repeated in boat forums, but this pretty much goes against every book I've ever read and study I've seen on composite construction as well as against best practices in other industries in applications where high strength to size and/or weight ratio is considered important.

In a normal layup (hand/vacuum/infusion) there are no "voids between the weave of the cloth" unless someone is doing something wrong.

[roverhi]

Can you site any studies or texts to support this idea? I understand what you mean, and it's repeated in boat forums, but this pretty much goes against every book I've ever read and study I've seen on composite construction as well as against best practices in other industries in applications where high strength to size and/or weight ratio is considered important.

In a normal layup (hand/vacuum/infusion) there are no "voids between the weave of the cloth" unless someone is doing something wrong.[/QUOTE]

Maybe vacuum bagging reduces the resin in the void but old style hand layup matt is needed. Bought a new Morgan 35 many years ago. Morgan used chopper gun and roving lay up schedule. Hull was laid up in two halves, on one side no problem, the other the chopper gun guy either didn't show up or the gun malfunctioned and they laid that side up without chop/matt. The side without chop/matt lacked stiffness. Every bulkhead, furniture etc. that was glassed to hull printed through to the outside. You could walk along the hull and see every bulkhead etc on a very lumpy topside. The layup thickness wasn't grossly different side to side and believe me I know because I drilled holes all over the boat 'cause I thought the problem was glass thickness. They'd laid the hull up with the proper roving schedule just left out the chop/matt.

Chopper gun layup in itself is not a bad construction technique if everything works and cloth/roving is also used in the layup. Cheoy Lee among others used chopper gun in their layups. The problem is uniform thickness of the chop layer requires a skilled operator and properly functioning equipment. That's not to say that chop as the sole glass in a layup is good. A combination of Matt/chop and cloth/roving is needed for strength and stiffness.

[Singularity]

Okay...so I'd previously read this linked thread where a poster in another forum really explains the mat vs woven with respect to ester vs epoxy construction in boats, and the logic of how/why woven-mat-woven X-ester laminates makes sense, particularly with respect to nuances that applies to boat building vs other composite structure construction.

My take/summary: when using ester resins, the shrinkage of the ester increases print-through (evidenced on external structures like the outside of the hull or decks, etc), while otherwise making difficulty in bonding of layers of woven glass, particularly the heavyweight rope-size woven used in old boats. In these cases, using mat makes sense.

But with epoxy...and this is what I neglected to recall...epoxy doesn't offer the same problem of interlaminar adhesion (or shrinkage) that ester construction does. Thus epoxy doesn't need mat between woven layers.

In the subject boat epoxy was used, as was mat. This doesn't suggest to me to be the best repair method as the mat effectively decreases the strength to size ratio, such that relatively more glass/glue is required to get the strength up to par. It's certainly easier to layup to a given strength by using a lot more material; maybe this is acceptable practice in boats but to me it's sort of lazy...particularly when doing small repairs where relatively little working of the layup is required, or, if repairing a really critical area where maximum strength and best practices would be expected.

[stnick]

You need to Call Frank Buttler of Catalina Yachts In largo Florida . He Designed this boat. He is the president of Catalinia . Just listen to Frank he knows his stuff. !
I think Catalinia has those keels made for them . Just listen and do what Frank says .
He will bend over backwards to make sure your happy with his boat !