Looking for info on compression block in a Catalina 30

[Project_Mayhem]

I'm trying to calculate the amount of material I will need to replace my compression block with G10. I have height and width. Does anyone know the depth of the wood block?

Contrary to popular belief, the 94 C30 has wood in the bilge

 

[dmax]

"Contrary to popular belief, the 94 C30 has wood in the bilge"
Yes, but just under the mast, it doesn't have plywood in the keel stub.

 

[OS2Dude]

I would not replace it with more wood. Search the internet on how to make a stainless steel jackstand. Or you can hire a local metal fabricator to make one. I also would not use the galvanized ones available online.

When I looked at options, the wood block is a multi-faceted and multi-layered monster. I'm not sure how you are supposed to replace it (in it's entirety) without cutting out the cabin sole under the head door.

 

[Project_Mayhem]

"Contrary to popular belief, the 94 C30 has wood in the bilge"
Yes, but just under the mast, it doesn't have plywood in the keel stub.

Yes, you are correct. I did a poor job of stating that fact

I would not replace it with more wood. Search the internet on how to make a stainless steel jackstand. Or you can hire a local metal fabricator to make one. I also would not use the galvanized ones available online.

When I looked at options, the wood block is a multi-faceted and multi-layered monster. I'm not sure how you are supposed to replace it (in it's entirety) without cutting out the cabin sole under the head door.

It's encapsulated in the bilge. In my case it's cracked and the encapsulating filler was chipped away. There's access to the aft side of the block through the bilge. Most people drill lots of holes to destroy the block. I'd really like to know the dimensions so I don't drill too deep.

I'm still debating how to do the repair. Right now I'm leaning towards destroying the block in the winter; Using an inexpensive steel jack to support everything and then build up a support using G10 in the spring

 

[OS2Dude]

IIRC, my block was about 4 to 6 inches all along the visible portion, and narrowed to a point over the next several inches. I drilled several shallow holes then used a chisel to remove the wood. Mine rotted from the inside out, so it was really only the outside edges of the block that were problematic to remove.

Check to see if your compression post and deck have been depressed due to the block deteriorating. You will likely need to add a temporary support to hold up the weight of the mast as you remove/replace the block. I'd also loosen the shrouds and stays a bit to reduce the downward pressure on the compression post. I did mine while the mast was down during a refit 3 years ago.

 

[Project_Mayhem]

IIRC, my block was about 4 to 6 inches all along the visible portion, and narrowed to a point over the next several inches. I drilled several shallow holes then used a chisel to remove the wood. Mine rotted from the inside out, so it was really only the outside edges of the block that were problematic to remove.

Check to see if your compression post and deck have been depressed due to the block deteriorating. You will likely need to add a temporary support to hold up the weight of the mast as you remove/replace the block. I'd also loosen the shrouds and stays a bit to reduce the downward pressure on the compression post. I did mine while the mast was down during a refit 3 years ago.

I had the mast taken down at haul out. I can install a mini jack after destroying the block to support the floor. Is additional support needed before this? If so, any ideas on how to go about it? The only methods I can think of is to toss some wood (or inflatable bags) between the floor and empty area around the bilge or pull up on the mast block plate I installed. I'm a little hesitant to do the plate as it's held in with lag bolts. If memory serves me correctly, there's roughly 1" of threads on each of the four bolts. I extended them a little bit when I added the plate and a bit of G10 underneath.

I was thinking of doing an initial depth of 4" with the drill. Does that sounds reasonable? I have a Bosch SDS rotary hammer I was planning on doing the big holes with and possibly some chiseling. Smaller holes would likely be done with a light to medium duty 120v DeWalt. I also have an oscillating tool, hand chisel and was considering borrowing a friend's straight die grinder