Catalina 25 SK weldment bolt wobbles & strange screws?

[jmczzz]

Refurbishing the keel on my 78 C25. I dropped the keel using the 4 threaded rod technique. With the keel out of the way with the rods still screwed in the weldments I noticed they all could be wobbled back and forth / side to side. It seemed to me the weldment threaded holes were stretched out a bit bigger at the bottoms allowing the rods to move. The rods were screwed in as far as possible by hand and felt firm. There were also screws screwed in next to each weldment that appear to be pressing against them. I asked on the C25 owners forum about this but no one knew. I found this pic searching google images. This is what mine look like except paint color. by you can see the slot head screws by each weldment.
What are these screws for? Any advice on changing out the weldments or not. (its a big job). or should i just use blue lock tight, or red, or epoxy the bolts in permanently putting off replacing weldments for a couple of years.
thanks James

 

[CloudDiver]

What appears to be a screw is actually in the mold itself. Not sure what Catalina was doing when they made the female mold, but the screws were there so every boat has those fake impressions of screw heads. They were in the fiberglass of my C22 in the same place. If you grind a little with a dremel tool, there should be nothing there but fiberglass. If you find a screw I'd be shocked.
If I had to guess what they were there for, the screws (bolts) were added to the mold for lifting.

 

[jmczzz]

You always amaze me with your knowledge and willingness to share it. thank you.
So now I am faced with the decision what to do about the apparent wobble of the threaded rods in the weldment.
Remember my mission at 73 is to complete my bucket list couple of years cruising the Great Loop. Do you think I could just epoxy the hanger bolts in place and go. Or tackle the weldment replacement job? I've already installed the 1 1/4" stainless bushing in the keel for the new wider hangers and the CD keel pads to add.
thanks again, James, jmczzz

 

[CloudDiver]

My guess is that at some point the P.O. had a stripped bolt and damaged the threads. After getting the broken stud out they used a slightly larger Tap like 7/16 to clean up the threads and make them bigger.... Keep in ming the bolt size for the C25 should be 3/8 where it is only 5/16 for the C-22.
Get some bolts from ACE hardware in 3/8 and 7/16. Gently thread them in to test if they fit and do or do not wobble. If the 3/8 fits but wobbles, and the 7/16 will not fit at all, then the PO could possibly have used a metric tap. To test that you'd have to use some metric bolts in that size range to repeat the same test as above. Be careful and only thread gently by hand, don't use a wrench at all.... last thing you need is a seized bolt!
Go to ACE hardware, they always have a more hardware than Lowes or Home depot and they will have metric sizes if you end up needing to try that. To answer your question about epoxy; Yes, epoxy is a good method to repair threads that are slightly loose. Generally this method works better when your hull is upside down, but I doubt you want to try that trick... You don't want to actually epoxy the bolts in (that would be bad), the trick is wax the bolts and then put them in with epoxy. This allows the epoxy to fill in the spaces of the damaged threads and them when cure you can still back the bolt out because the epoxy won't stick to the wax.

 

[jmczzz]

More good ideas. I'll go to town and get some bolts and check it out. After the epoxy sets with the correct waxed bolts should I take them out clean off the wax and reinstall with the suggested blue lock tite?
thanks, James

 

[CloudDiver]

Yeah, if you decide to use epoxy to repair the threads after the bolts are removed use some acetone or denatured alcohol on Qtips to clean the threads. As a matter of fact, also clean the threads that way before you put the epoxy in to make sure the epoxy will adhere well. If you are working upside down, thicken the epoxy so it will stay up there. Not peanut butter thick, bust just thick enough to work its way between the threads. Zipper wax or beeswax works well on the bolts.

 

[jmczzz]

checked out the bolts, they are the 3/8 x 1 1/4 16 nc.
I epoxied one weldment for test following your instructions yesterday afternoon. This morn I just removed the epoxy carrier bolt, ran a thread chaser in and out several times to clean up the weldment. put a bolt in and the play (wobble) is much less. Estimate a 2/3 rds reduction in play. when the bolt is all the way in (finger tight) there is insignificant wobble, (based on my experience with automotive work.). I would say a successful result. I will give the remaining 3 weldments the same treatment today. If they all have this result i will consider that problem solved.
Note: I did discover a blot top rounded button of a rubbery boat life type substance in the tops of two of the weldments. I removed twisting a bent wire hook.
thanks James, jmczzz

 

[CloudDiver]

checked out the bolts, they are the 3/8 x 1 1/4 16 nc.
I epoxied one weldment for test following your instructions yesterday afternoon. This morn I just removed the epoxy carrier bolt, ran a thread chaser in and out several times to clean up the weldment. put a bolt in and the play (wobble) is much less. Estimate a 2/3 rds reduction in play. when the bolt is all the way in (finger tight) there is insignificant wobble, (based on my experience with automotive work.). I would say a successful result. I will give the remaining 3 weldments the same treatment today. If they all have this result i will consider that problem solved.
Note: I did discover a blot top rounded button of a rubbery boat life type substance in the tops of two of the weldments. I removed twisting a bent wire hook.
thanks James, jmczzz

Nice work James... Epoxy does a good job of 'restoring' loose threads. The caulk you found in the weldments is probably there because the PO hade used it as a sealant/thread-locker... It isn't a bad thing to use for a sealant. Check-out Loc-Tite's website and see if there is a specific number thread lock they recommend for stainless steel, I know there is one but I can't remember the number. I used regular Loc-tite blue because I know it is waterproof when dry, but maybe they can make a better recommendation for stainless specifically. Sometimes you can get a product rep to send you a sample pouch so you don't have to buy a small bottle at $30!

 

[CloudDiver]

Also, if you want to fully remove all the play from the first threads you gave the epoxy treatment to, clean out the threads really good with Qtips and acetone or denatured alcohol again and repeat the treatment with epoxy one more time. Make sure your wax coating on the bolt threads is as light as possible but fully covered. I'm willing to bet you can get all the play out of threads so there is no movement at all. I like the 3/8 bolts on the C25 hangers, I wished they had used 3/8 on the C22.