Catalina 42 MK 2 Strut questions

[Dorfl68]

I am really close to buying a Catalina 42 MK 2. One item from the survey is the strut - as you push on it, you see it move a bit. The surveyor is talking about "resetting the strut" - but when I look at the design (Prop Strut for C-42 with Cutlass Bearing), it seems to me that this could be a lot easier - take out of the sleeve, make sure sleeve is still solidly set. If so, just put it back in as instructed with the epoxy filler.

Does anybody have experience with this? is the MK2 strut the same as MK 1 (The site only says Catalina 42). I wouldn't do myself, likely, but obviously kind of important for cost of fix.

 

[Ralph Johnstone]

Welcome to the site @Dorfl68 .

These struts seem a little problematic to me and I don't even have one of this design.

We had a similar problem posted a few days ago :

Propeller Shaft Bracket on 35S5

Hello All, I was wondering if anyone has experienced their propeller shaft bracket dropping down as seen the attached picture. If so, please let me know what you did to repair it. I believe some fiberglass cloth and resin will keep in back in place, however, if you have a suggestion please let...

forums.sailboatowners.com

The biggest problem I see is that once the strut comes loose in the "strut receiver" the shaft alignment becomes a real challenge. Improperly aligned, and real problems are waiting down the road.

With a conventional solid cast bronze strut, once installed (hopefully correctly) there is no danger of it coming loose.

 

[Dorfl68]

I see what you mean but that's just the Catalina 42 design, which did them well for hundreds of boats. So I will not change that...... For what it's worth, this thing is straight and aligned. Attaching a photo,- not much to see but well...

 

[Ralph Johnstone]

For what it's worth, this thing is straight and aligned.

Can you explain how you determined the shaft is aligned ? Catalina put a lot of precise work into getting this alignment correct during construction but unfortunately it slipped during operation. This is not a slap dash installation. To ensure you fully understand the precision required for proper shaft alignment, find attached a copy of "how to."

Yes, horizontal alignment of the strut is fixed, that's not a problem. Vertical misalignment is not fixed. Consider if the strut is fixed too low :

1. You will have excessive wear on the upper aft portion and excessive wear on the lower forward portion of the cutlass bearing.

and

2. You will have misalignment with the shaft coupling. That's a long unsupported run from the cutlass bearing to the shaft coupling to even think about using the coupling alignment to set the position of the strut.

If this were mine, I would remove the shaft and do an alignment from the transmission flange centre to the centre of the cutlass bearing. This is the procedure for setting the location of a conventional strut during the construction of the boat.

that's just the Catalina 42 design, which did them well for hundreds of boats.

............................. until they found the part had a serious problem and went to the conventional design that other manufacturers used. Most people would never realize they had a problem or if they did notice a problem "out of sight, out of mind." I imagine the adjustable design was used as "assist" during the initial alignment during construction.

 

[Ralph Johnstone]

I had forgotten you are still in the process considering buying this boat This is a complex (meaning costly) but perfectly repairable job. Do not let the surveyor sell you on simply resetting the strut. He's out of his league. I don't know how many hours it will require, but it's a long drawn out job for a "competent re-alignment". Maybe ask for a 5-7K drop in price to allow for permanent repairs ?

If you are satisfied with the rest of the boat, don't let this stop you. Perfectly repairable but long and somewhat costly.

 

[Dorfl68]

Ralph, I appreciate the time. "aligned" here as determined by the surveyor given the small movement up and down in the strut - and he discovered it. Yes, I will get an estimate for this but given this specific construction, it might actually be simpler - but the issue is the uncertainty. Personally I think his report will show numbers in your order of magnitude, he was very clear that this needs to be fixed and that's it's not cheap

 

[Ralph Johnstone]

Personally I think his report will show numbers in your order of magnitude, he was very clear that this needs to be fixed and that's it's not cheap

Now comes the hard part. The actual cost of the repair vs. how badly you want the boat. It's got to satisfy you.

Yes, I will get an estimate for this but given this specific construction, it might actually be simpler

Be careful who you approach for the estimate. You will find plenty of engine mechanics but I think this is a difficult area in which to find a specialist. I would think any estimate would simply be a maximum estimate for the total job and no short cuts. Just to get an idea where the alignment is at present would require an alignment check at the coupling flanges. And then move on from there until you are ready to fix the strut in place. And THEN fix the strut so that it's guaranteed to never come apart again. Filling with epoxy filler didn't seem to work worth a damn for neither you nor @KGarvey :

 

[Hayden Watson]

I would think that the use of epoxy in filling the void for the simple reason that it is repairable. I have heard of C42's that got strut damage from fouling a line while motoring and needed replacement. Epoxy is a very strong product, but it has one weakness and that is heat. I will begin to soften at around 180º. To remove the strut, you remove the three strut bolts and then apply heat to the external portion of the bronze strut. Broze is an excellent conductor of heat and will quickly move the heat into the portion encased in the epoxy filler which will be softened an allow it to be removed.

 

[Ralph Johnstone]

Epoxy is a very strong product, but it has one weakness and that is heat. I will begin to soften at around 180º.

We still don't know the failure mechanism of the epoxy in the above two cases that have been presented to SBO. Given that we have two identical cases here, I think it safe to say there have been many more cases that have not been noticed or the given the old "out of sight, out of mind" heave ho.

The one thing in common to both cases is some degree of vibration. How many years of service is still an unknown as we don't have the age of either boat. Vibration or not, epoxy is NOT a suitable sealant for this design of strut. Maybe some form of flexible sealant ? Getting it into all of the voids would not be an easy task. I also think this is why these struts are not widely sold at this time (if at all).