And another compression post block thread

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dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
So I will be doing the bilge block for the compression post in the next month or so on my soon to be 90 C30. I know there are blocks available from Catalina or Catalina direct that are oak. From the pics they look solid. Is there any reason one couldn't use 1" thick hardwood board to build it layer upon layer epoxied together? I know some have used G10 also epoxied together. Good stuff but nasty to work with. I don't have a problem with wood and if it's sealed and the bilge is dry should last my lifetime.
Anther thought would be a stainless jack screw epoxied in place. This would apply the compression post downward force directly to the keel and when installing it could be raised to counteract any deck sag.
Just saying...
 
Mar 11, 2010
292
Catalina Tall Rig/ Fin Keel Deale, MD
I used G-10, but in hindsight I would use white oak for the post support. Cutting the shapes needed WAS a pain in the butt. However, for the bilge filler plywood and backing up the keelbolts, go with the Catalina engineered remedy first. Then add an epoxied layer of G-10 on top, for something substantial to torque the keelbolt nuts down on to. I found that I still needed to build up another inch after the three alternating layers of mat and roving. Does this 1990 boat actually have the post problem? Was it a survey finding?

Rob
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
Rob - I believe that there is no plywood in my boat but there is a compression post block and that's what is mush.
As far as I know no C30s after 86? had the ply filler in the bilge for the keel bolts. I plan on emailing the factory and discussing options for replacing the post block.
Unless there are forces I'm not considering I will ask them about using a SS jack screw (custom made of course). Basically a plate at the top and bottom with an adjustable screw in between. This way I could slacken the rig, dig out the block and install jack screw, tension it, secure it, and then re-tension the the rig.
 
Jul 1, 2004
398
Catalina 30 Atlanta GA
Hull 5397

I'm confused here..............According to the 30 Catalina Association technical information listing that provides factory updates on the 30, hull number 5397 which was a Mark II 1988 model was the first to get the replaced wood compression post support with the updated metal support. Unfortunately I missed the metal support post by a few hundred hulls. Are you saying your compression post is wood in your 90 model? :confused:

Bob
1988 Mark II
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
Hi Bob
There may be a metal post inside my compression post. My '90 shows wood from floor to ceiling so I don't know. . I'm referring to the wooden block under the floor that's sits in the bilge. I understand that all C30s have a wooden block in the bilge.
Also I'm not referring to the ply that the keel bolts go through. That was I believe eliminated around '86.
I sent Kent @catalina an email so hopefully he will get back to me soon.
 

DanM

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Mar 28, 2011
155
Catalina 30 Galveston Bay
dj,

When I replaced my compression block on my '85 TRBS I used pieces of one inch white oak to build up the block. The factory block that had failed by the way appeared to be made of teak plywood.

It is such an odd shape working in that area of the bilge that I found I was able to cut each piece of white oak to about the right size and then use a belt sander to make the final fit. I would then wet each piece out in some West System epoxy and then move on to the next piece. The final piece was made sort of wedge shaped and I drove it in (fairly gently) with a two pound hammer.

When it was all done I then covered the open bilge end of the new compression block with several coats of epoxy. I did remove the mast and I would also say it was one of the worst projects I've ever done on my boat! :) Working in that tiny little area of the bilge is hard work. I used chisles, drills and a Sawsall to get the old rotten block out. That area looked nothing like the Catalina drawing on my boat, must of it was filled with an epoxy like slurry mix that was like concrete. There was no way I could have ordered a replacement block that would have fit such a randomly shaped place.

Here is a photo that shows the process of each piece of that makes more sense...

DanM.
 

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dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
Thanks DanM- that's what I was thinking with replacing with wood. I would think 1" board might be a little cheaper than a big block.
Haven't yet heard back from Catalina on my SS jack screw idea.
 

DanM

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Mar 28, 2011
155
Catalina 30 Galveston Bay
dj,

I've heard the SS jack screw idea talked about over the years but I've never seen one actually built and put in place. If you have access to the tools necessary to build one I can't see why it wouldn't work but it might turn out to take more engineering (figuring out how to keep it stable and also providing oxygen to it so it doesn't rust) than it's worth.

The area that you will be working in is much smaller than the Catalina factory repair drawing shows, mostly because they show it as a nice clean turn of the bilge area wherein the reality is that the area has a concrete like slurry mix poured around it that would take a jack hammer to remove. Using a solid block provided by the factory would require massive modifications IMHO, and not be worth the time to do so.

I think there were quite likely a lot of different types of material used for the compression block over the years (particularly in the early boat since they probably didn't think we'd still be sailing and fixing them 30 years later!). When I spoke to the factory they told me that they used an "African hardwood that doesn't absorb water". What I really found in my boat was scraps of teak plywood laminated together in a rough block surrounded by an epoxy slurry mix.

Given that the cruddy teak plywood lasted about 20 years on my boat I think my epoxy coated white oak repair should probably be good to carry the load for another 20 years or so or at least until we are all sailing old wing sail, cabon fiber retired America's Cup boats around the bay for fun. :)

DanM.
 
Oct 5, 2008
28
catalina 30mkii alameda ca
Could the hardened concrete slurry mix as described by a few possibly have any structual load capabilities therefore doing what the original compression block was intended to do? Secondly, would it even be feasible to inject a hardening resin of some sort into the cavity or "muddy wood block" to do the same job as the original compression block? Just two of my agonizing questions, and thanks to all who have jumped into this discussion.
Bill.
 
Mar 11, 2010
292
Catalina Tall Rig/ Fin Keel Deale, MD
Bill/ Fortitude,

Yes, I think the resin "concrete" mix was put into there to fill voids between the wood and hull. Some boats have more or less filler than the next. However, to fill the entire area with resin epoxy is more expensive and time consuming than using built-up layers of new material. Mix up West System to coat the pieces. Stack a few in place. Add High density filler to the epoxy batch and trowel (or syringe) the extra thickened resin into the voids in between. Repeat, until stacked to the top. Have all the pieces cut and ready to go in order. I used foam board and a razor knife to make templates and then transferred the needed shape to make each piece. Lay out plastic sheet, then cover that with cardboard, inside the boat.

I would also say, one large quantity of epoxy resin & hardener of that size, that could fill that large a space of volume for the post support would get so hot, it would catch on fire. To do it all resin, you'd have to do several separate pours due to the heat factor anyway. You're still doing stacks, and there's too much trial and error to see how deep you could make each layer without it catching on fire. And what do you do it if it does? The sealed white oak stack is the most efficient in cost and time.

And that's how I spent my February of 2011 :D.

Rob
 
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dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
I was down the boat today and started to investigate the post block area. I have the U shaped dinette so had to take off the settee closest to the bulkhead to get access. The block is definitely gone. Also looking through the hole where the mast wires come out I didn't see any metal just the other side of the wood compression post. I need to cut the fiberglass weave to see more of the block area which I hope to do this week. Here is a picture of it so far.
 

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dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
So yesterday I dug into the bilge. As suspected there was little wood left.
Here are some photos. There is a volume forward of the block that basically is a good space to capture standing water cause of the dam made when the factory installed the block. Also the shower drain hose was captured in there making service impossible.
 

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Mar 11, 2010
292
Catalina Tall Rig/ Fin Keel Deale, MD
Ah, the memories... Shirley, I jest (I know, don't call you Shirley :D).

Looking at the water stains on the post where the conduit comes out indicates it's following down the wires from the mast. I made an aluminum cap plate to cover my masthead opening by drilling some holes and tapping 10-24 threads for machine screws to try and minimize it. Another neat idea put out there by OldSkool Neal is to route those wires over on the shower side so it avoids the support block via the shower drain. His actually exits the post at the top and then runs down, all in the head area and covered by teak molding in the corner. Pretty slick.

Fun Times!

Rob
 

jrowan

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Mar 5, 2011
1,294
O'Day 35 Severn River, Mobjack Bay, Va.
Say guys, I can see the crack in D J's photos of the fiberglass wall in front of the compression block, but how did U know that your compression blocks had failed/ were rotted. I've checked my bilge & see no cracks around this area. I also have a heavy duty steel tabernacle base at the bottom of my mast, so that it could be raised & lowered more easily. I believe that this has helped to support the load of my mast & helps displace the load / pounding that occurs. My boat is a 1980 & when I hear of 1990 models having rot there it makes me worry a lil', but I don't want to create a problem if there isn't one. How did y'all know there was a failure?
 
Mar 11, 2010
292
Catalina Tall Rig/ Fin Keel Deale, MD
Previous to purchase, I researched the C-30 in-depth as to what were major concerns. When I looked at purchasing #3518, the post support area in the bilge was slathered with globs of an epoxy patch job. The surveyor said it was something he's seen before on this model, of this vintage. My PO was very honest and described how he drilled holes into the area and injected epoxy to strengthen the wood. Based on the price we agreed on, it was very fairly valued regarding the boat's total condition and features.

Everybody said, "Sail the boat, it's not a Stratavarius" and I sailed for the whole Spring and Summer before I recognized water weeping in from around one of the forward keelbolts. That was my impetus. I had no hesitation to hole-saw a core sample to see what I already knew. If yours turns out dry, it would be easy to repair the cutout by epoxying the core sample right back in. What to look out for:

I have gelcoat spider cracks at our post base. That's the rig force coming down onto an unfirm base that's slowly giving way. Look for water staining at the post like dj's. Look to see where the mast wiring comes into the lower part of the boat. Mine was a hole drilled right through the support, and the wires continued along the bilge wall towards the engine area. Ours was soaked at where the wires came through the patch.

Again, my getting into this was the keelbolt issue and fear of crevice corrosion of the bolts sitting in the wet bilge ply. The post support was a bonus!

Rob
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
I agree with what Rob said. In my case I stuck my finger in the hole of the glass that was there. It was a soggy mess. If there is no access, tap around to sound it out or drill a hole through the glass. It is only one layer of glass anyway. Stick a awl or something into the wood. Mine was basically dust. I'm almost done with the new support and should finish this weekend. I'll take pics.
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
Here's an update on my compression block. I used a stainless 1" threaded rod and pipe with a 1" aluminum plate at the top. The bottom is anchored with G10 and epoxy. I don't think it's coming out. I raised the forward portion of the bilge so any water that enters up there will drain into the bilge aft of the metal.
 

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Mar 11, 2010
292
Catalina Tall Rig/ Fin Keel Deale, MD
Nice idea. Compact. You might consider a larger, stainless plate on top that's wide enough to seat the post fully. Do you think the post still bears on the fiberglass at all?
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
The plate is longer than it was wide so I think it's adequate. I could keep cranking on the nut and push the post through the roof if I wanted. I had the rig pretty loose and now it feels more snug. I'll take a reading with the loos when I get down there again. It's 90 degrees and windless- not my cup of tea.
 
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