wood discoloration

[John Reimann]

I was looking at a 1999 Catalina 36 that is for sale in my area. I noticed some wood discoloration (blackened) on the port side just above the sole and at the sole itself. Just forward of this, on the other side of the wood, is the head. I was wondering if water from the head could possibly be leaking through and causing wood damage. Then I looked online and saw a 36 of a similar year with the same problem. Above is a web site where this can be seen on this other boat. Does anybody know what might be the cause of this and whether it is potentially serious or not?Thanks.John

 

[Kevin]

Sealant

The problem comes from the type of sealant used to seal the head wall. What I have discovered is that, most of the time, the bulkhead is sealed with silicon. The trouble with that is that it is not flexible. The first time someone leans hard enough against the wall the seal is broken, thus allowing water to seep down to the unfinished bulkhead. The same thing has happened on my boat. What I have done to prevent any more damage is to reseal the joint with a polysulfide caulk. While it has a preety strong adheasive quality to it, it remains very flexible. That's why it's great for bedding deck hardware. Silicon should only be used to bed deadlights. They do not open or close, nor should there be any twisting motion to rupture the seal. Hope this helps. By the way, Don Casey has a great list of resources. Here's the one on sealants:

 

[John]

further question

Thank you, Kevin. If I do buy this boat, I will definitely use this sealant. I had suspected that something like this was the problem. However, I have a further question: How serious do you think the damage is liable to be? Do you think that these wood panels will need replacing due to dry rot that is only fully visible from the inside? Do you think that there is liable to be other hidden damage?John

 

[Kevin]

It's really up to you

On my boat the "damage" was confined to about 1" or so above where the screws attached the bulkhead to the sole. I used an awl and poked around a little and was able to determine that it was more discoloration to the teak veneer nore than anything else. Below that the bulkhead it supposed to be marine plywood which is rot resistant. After having my buddy push real hard from the head-side, I wasn't too worried about it. Again, it's up to you...

 

[Stephen]

John

John,I had the same problem on a previous boat - Capri 26. Problem started from a gap in the floor seal inside the head/shower area. I poked around the "outer wall" with an ice pick and found then problem was approx 2 inches up the wood and a lot of the backing plywood was rotted as well. The panel did not have good support at the base and a repair was in order. My surveyor recommemded reducing my offer for this problem (as well as others)...saved me a LOT of cash! As said many times, it really pays to get a good survey AND you will learn a lot.I did not want to remove the complete panel of plywood with teak veneer trim...this would have been a major task. I fixed it by digging out all the rotted wood and re-filling with bondo. I stained and added a 3" piece of trim molding at the base to cover this fix. The final result looked great and was SOLID. I also removed the old sealant and recaulked the interior of the head with an excellent product called Life Seal. Problem fixed!Good luck.