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meshugah · 02-08-2022, 21:58

Hi Calif.Ted, thanks for your post. Good to know that there is a keel manufacturer based in Sydney. However, I am trying to avoid replacing the keel which I am sure would be a very costly exercise. As a first step, for peace of mind, I want to determine whether or not the existing keel bolts are still in sound condition. I'm planning to further investigate the ultrasonic testing method offered by a local specialist who does this type of testing professionally for the aircraft industry etc. If he assures me that the method produces reliable results even when testing curved J-bolts, then I may get that testing done because it is not expensive. An "all-clear" result would provide some peace of mind. If however, the testing indicates corrosion or cracking in one or more of the bolts, I will in all likelihood, haul the yacht out of the water and get a tradesman to investigate further and possibly replace one or more of the bolts using the method described by Searles. I've got to take it one step at a time.

Happydrv · 12-08-2022, 10:13

Join the Catalina 42-425 Facebook page. Not a FB fan but lots of us on there have boats of your vintage, never had a keep problem.
Hum 497:

Icarus · 12-08-2022, 22:46

Quote:

Originally Posted by meshugah

I have a 27 year old Catalina 42 Mk2 based in Melbourne Australia and am concerned that the keel bolts (i.e. keel studs) may be degrading. It has been suggested to me that I get an ultrasound test done on the studs while the yacht is sitting in the marina. Apparently the people who do this connect a probe to the very top of the keel stud and send an ultrasonic signal through the stud. Based upon the reflections of the signal they can tell whether there is any serious crevice corrosion somewhere in the stud. Has anyone had experience with this type of testing? Is it reliable and worth doing? The tester has quoted $350.00 to test all 8 bolts and to provide a report. This is not a lot of money, if the outcome can be relied upon. Does anyone know how long the studs actually are on a Catalina 42Mk2? Are they screwed into the keel or bonded some other way. One tradesman advised that the only way to do this properly is to do a haul-out, remove the mast and rigging, separate the keel from the hull, remove the studs from the keel and replace them. That would be a huge and costly exercise. Any ideas and tips would be highly recommended. I am just trying to get a condition report on the keel studs as efficiently as possible. Thanks for anny assistance you can offer.

Ultrasonic testing is certainly the go, and yes it works, we use sonic testing in the mining industry ..and yes it works
350 is cheap and a good starting point.

Trouble is some keel bolts might be imbedded and attached to an internal reinforcement structure of the ballast and cant be removed. especially in lead ballasts.
if the ballast is cast steel they most likely will be screwed in to it and can be removed one by one, possibly without dropping the ballast

What is the material of the keel bolts? SS, bronze, Monel, steel?
SS is the worst.

Icarus · 12-08-2022, 22:49

Quote:

Originally Posted by Calif.Ted

As Searles has mentioned Catalina stresses they use "J" bolts molded into the keel so that whole "replacement" operation becomes problematic. The only boats known for bolt problems were the old 27's.

Crevasse corrosion is the killer...

vic008 · 13-08-2022, 01:33

Wooden boat here. Think I have always got saltwater in the bilge (from sterngland at least). Never worried about it!

meshugah · 13-08-2022, 19:20

Quote:

Originally Posted by Icarus

Ultrasonic testing is certainly the go, and yes it works, we use sonic testing in the mining industry ..and yes it works
350 is cheap and a good starting point.

Trouble is some keel bolts might be imbedded and attached to an internal reinforcement structure of the ballast and cant be removed. especially in lead ballasts.
if the ballast is cast steel they most likely will be screwed in to it and can be removed one by one, possibly without dropping the ballast

What is the material of the keel bolts? SS, bronze, Monel, steel?
SS is the worst.

Thanks for the post. I put in a phone call to Catalina in Florida last week and spoke to a very helpful guy called Warren. He explained that the keel bolts are either L-shaped or J-shaped and are embedded into the lead at the time of keel construction. The L or J shapes mean that the bolts cannot be inadvertently pulled out of the keel due to large forces which may be applied through a grounding or similar. The bolts are made from 316 stainless steel and 1 inch in diameter, with 1.5 inch nuts. Warren advised that he had never heard of anyone doing ultrasonic testing on the bolts, but advised that I should ask the ultrasonic testing contractor to provide me with sample reports, graphs or images, showing what type of report I might expect from him. That was good advice. Warren was keen for me to take photos of the bolts as they presently are (i.e. crusted up with some surface rust) from inside the bilge and then clean up the bolts with a wire brush, or circular wire brush attached to the chuck of a battery operated drill, and take additional photos after the clean-up. He was keen to see both before and after photos, which I will take and send to him. He also explained that the keel was bonded to the hull with a very strong bonding material and that material alone would in all likelihood keep the keel attached to the hull. He further explained that the hull was about 3 inches thick where the keel bolts passed through the hull and that during manufacture, bonding material was applied to each each keel bolt in a teepee tent-like shape and while the bonding material was still uncured, the keel and hull were brought together forcing the uncured bonding material up into the holes in the hull for the keel bolts thereby binding the bolts into the hull supposedly making a very strong and water-tight join. He further explained that while at manufacture the nuts were tightened to around 150 ft-lbs, when I next did a haul-out I should remove each nut in turn, inspect and possibly replace each nut and then retighten each nut to at least 105 to 110 ft-lbs. My next step is to get sample reports from the ultrasonic testing operator to determine whether the testing is likely to produce reports which are usable for drawing conclusions about the condition of the bolts.