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meshugah · 30-07-2022, 21:28

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.

AKA-None · 30-07-2022, 22:05

By any chance did you try reaching out to Catalina?

meshugah · 30-07-2022, 23:55

Hi AKA-None, yes I emailed Catalina about a week ago but am yet to receive any reply. I'm disappointed that I didn't even get a response like "we will look into this for you and get back to you". Maybe I will still get a reply in due course.

Searles · 31-07-2022, 02:14

Having assembled a number of Catalina yachts ,and sailed and raced the deep keel 42 mk 2 ,the keel is cast lead with the bolts cast in ,despite groundings and knockdowns ,plus the loss of a rudder ,but have never seen any movement in the keel ,when next on the hard it may pay to check the torque of the keel bolts .

meshugah · 31-07-2022, 05:09

Hi Searles,

Thanks for the post. Do you have any knowledge of crevice corrosion in Catalina 42 Mk2 keel bolts? If so, please advise. In addition, is it necessary for the yacht to be on a hard stand to check the torque of the keel bolt nuts, or can this also be checked when the yacht is sitting in the water.

Renoirpierre · 31-07-2022, 08:51

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.

I have seen this type of testing used to assess the integrity of studs/bolts in the Oil and Gas industry. If done properly, it is an effective way to look for cracking or corrosion.

Calif.Ted · 31-07-2022, 10:04

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.

Searles · 31-07-2022, 16:56

I for one would not play with keel bolts with the vsl afloat,with the vsl on the hard with the full weight on the keel or at least most of the weight carefully back off the foe and aft end bolts , remove backing plates ,clean and check carefully if they look ok replace the plates with a little fiixteck or similar and re tighten bolts to set torque ,I think it was north of 150 ft lbs ,but please check ,if the end bolts are ok ,I would leave the rest as the end plots take a lot af accidental load .⛵️⚓️

meshugah · 31-07-2022, 21:35

Thanks guys for all the useful input. Its very much appreciated. Unfortunately, over the last 18 years since I bought the yacht, I have not been as careful as I should have been to ensure that the bilge was kept dry. For much of that time there would have been an inch of two of water in the bilge. That's why I'm now concerned about keel bolt corrosion. What do people do if they find corrosion in a "J" bolt which is molded into a lead keel. It would appear to be almost impossible to remove and replace. I guess one option would be to drill new holes through the bilge and deep into the keel and to tap the holes in the keel, screw in new studs and secure them with backing plates, washers and nuts via the bilge. Does that appear to be a reasonable option if any of the "J" bolts are badly corroded? Are there other, more suitable solutions? Any advice would be much appreciated.

Searles · 01-08-2022, 02:40

Having sailed in Catalina’s 42 mk1 and 2 have yet to find a keel bolt fault or failure ,given a keel stept mast water in the bilge is usual not unusual ,however I’m you break or destroy a keel bolt it’s not the end of the world,first enquire if Catalina has a set pattern for the bolts in the 42, once known ,easy enough to drill a slightly oversized hole in the glass and a thread size hole ihthe lead,drill down 10 or 12 inches ,locate the holes on the outside of the keel ,drill a connecting hole horizontally across the keel go from side to side right through ,for 1 inch bolts drill a2 inch hole fit apiece of bronze bar drilled and tapped to suit the new bolts wind in from the top and re nut ,as many as necessary ,a bit fiddley but have done this on much bigger keels .⛵️⚓️

Searles · 01-08-2022, 02:42

P s use round bronze bar ⛵️⚓️

meshugah · 01-08-2022, 04:46

Searles, that's an extremely clever method. So one does not actually tap the lead keel itself, but one taps the horizontal bronze bar and screws the long stud into the horizontal bar. Is that correct? I will contact Catalina re the pattern for the location of the bolts in the keel as you suggest. Hopefully they will reply eventually. Your input is very much appreciated.

Searles · 01-08-2022, 18:20

Not necessary to tap the lead keel ,but the drilling in the lead is better if it’s a good fit for the new bolts ,by the way don’t use all thread ,have proper bolts made to suit ,use monel k 500 if possible if s/s 2205 ,if you have to use all thread go up to 1.25 ,once again have never seen bolt problems on a Catalina 42 ,⚓️⛵️