Hollow Transom Surprise

[Not Too Shabby]

I'm in the process of getting to know my 1976 C22. I recently observed a small bulge at the top of the inner fiberglass layer of the transom wall (from inside the lazarette) to the starboard side of the mounting bolts for the aftermarket swim ladder. Some investigation revealed that the transom, at least in that area, is hollow. I will take the necessary steps to ensure no future water ingress at the ladder mounts but my immediate concern is dealing with the lack of core.

I presume the transom originally had a wooden core, correct? If so, I'm strongly considering pouring some ceramic compound, such as Carbon Core or Arjay 6011 as opposed to re-coring the transom. There are videos that show the process to be rather straightforward. I've searched this forum and haven't found any threads on this topic so I thought I'd ask whether anyone has any experience/advice/opinions to share.

First post, btw! Happy to be aboard.

 

[Gene Neill]

Welcome aboard, Shabby! Nothing to worry about, the C22 transom has always been hollow. Here's a random pic of mine, while upgrading the rudder gudgeons...

 

[dlochner]

What you are seeing is pretty common and is a function of how boats are built. There are 4 major components, the hull, deck, headliner, and pan, built separately and then joined. This process leaves gaps between the deck and hull and deck and headliner. If the transom needs coring it is cored while building the hull component and not the deck component.

If the swim ladder was attached without or with an inadequate backing plate there may be some distortion of the hull. A photo would be helpful. Another area to look at is the motor mount. If a prior owner used a motor that is too heavy, that too can cause some distortion.

 

[Not Too Shabby]

If the swim ladder was attached without or with an inadequate backing plate there may be some distortion of the hull. A photo would be helpful. Another area to look at is the motor mount. If a prior owner used a motor that is too heavy, that too can cause some distortion.

That must be the culprit. As I was drilling holes to mount a pulpit I discovered a bulge on the starboard side. I slid my phone over the top (of the "pan"?) and snapped some video, revealing the lack of core. What a relief to know that I don't have a messy project on my hands! Thank you both for the replies. You'll see that the bulge is indeed above one of the plates for the ladder. You'll also see the holes for what was probably a different ladder previous to this one.

I have checked the port side and the motor is backed by a hefty wooden block. I presume others have used a stainless steel plate here. A rudder gudgeon upgrade a la Gene might be in order as well. Otherwise, all seems intact on the port side. It's only this one small area, in the photo, that is not congruent with the rest of the boat. I'm able to take a screwdriver/chisel/etc. and bend that bulge back enough to wedge a backing plate in there for my pulpit. So, it seems I can proceed with the pulpit.

 

[LakeShark]

Use threaded rods for the grunion replacements. Then you avoid cutting the holes in the cockpit liner.

Also welcome to the C22 family. I highly recommend the Catalina tech manual as it has tons of tips and tricks learned over the years.

https://www.catalina22.org/index.php/technical-manual

 

[Not Too Shabby]

Use threaded rods for the [gudgeon] replacements. Then you avoid cutting the holes in the cockpit liner.

Indeed it would be nice to minimize the cutting of holes. I'm trying to imagine how threaded rods would allow for me to not drill holes...

Perhaps this is because I can tighten the exterior nut (against the gudgeon) after the nut on the inside of the boat has been screwed on; thus, the excess length of the rod/bolt extends aft of the boat and I can just cut that off, leaving me with the exact length of rod I need to mount the gudgeons? Is that what you are implying?

The Catalina 22 association is surely worth poking my head around in as well. Thank you for the welcome, and thank you for the link.

 

[LakeShark]

I'm trying to imagine how threaded rods would allow for me to not drill holes...

The grugeons are mounted to brass plates in-between the liners. The process is as follows

1. remove the 2 outer screws only
2. insert threaded rods into the 2 outer holes
3. remove 2 inner screws
4. remove grudgeon sliding it off the threaded rods
Note: the thredded rods will hold the plate from falling down and allow you to realign when it is all re installed
5. clean up sealant etc
6. install new or replacement or rebeded grugeon
7. install 2 inner screws (preferably new or at least cleaned up)
8. tighten inner 2 screws so sealant starts to oose
9. remove threaded rods in outside 2 holes
10. install 2 outside screws and tighten assembly

It is actually quite a simple process and I used to mount a spacer under the top grugeon to remove all the weather helm. The idea is not originally mine but handed down by some of the racers at the Catalina 22 National Assiociation. They're a great group and yes well worth your time and money to join.

Threaded rods to hold plate. Note: the lower plate is accessible on my new design from the long cavern on the port side.

Class rules allow for 1 inch spacer on upper grugeon. This reduces weather helm and drag.

The rudder must remain behind a vertical line extending down from the transom (it cannot sweep back under the boat). This movement does what the rudder craft rudder does with the OEM rudder and allows the boat to sail fully balanced. This means that under most sailing angles requires only a couple fingers on the tiller to adjust course. Not the typical bench press in a blow. The draw back is that when sailing hard in heavy (20+) winds your rudder itself will see the extra strain and if your rudder has water in it or a rotten core it may break. Then again a bad rudder may break anyway so there's that.

 

[Not Too Shabby]

That makes sense. Thanks for the tips!

I did a little gudgeon research and it turns out my boat already features the reinforced 3/8" gudgeons as your boat has. I have enough work ahead of me with the pulpit, cleaning, upgrading chainplates, reinforcing cleats, changing cable and hose, resealing windows, etc. so I'll hold off on the gudgeons for the time being. But it seems I might want to at least add that 1" spacer as you've done, perhaps once I've logged some hours on the water. The rod technique is great to know. Thanks again.