J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Removing the Outer Hull Skin & Core Adjacent to Keel

Earlier this year, through the use of a moisture meter and some core samples I determined that Breezin' had wet core on the starboard side from approximately the location of the fresh water intake forward to just below the anchor locker. After agonizing whether this problem should be attacked from the inside or outside (and reading the experiences of those who have done this before me) I decided that the most complete way to thoroughly dry and address the issue was from the outside. I may regret that decision once I begin fairing the bottom but that is a long way off at this time.

The plan was simple (although I will keep it brief for this discussion), mark out a grid on the bottom of the boat, take core samples, identify "wet" areas of the hull, and remove 6" square sections of the outer skin in a checkerboard pattern in those areas where the moisture was high. All went as planned finding wet but solid core aft but things changed when I cut out a section just aft of the keel.

I removed a section of the outer skin just in line with the aft end of the keel and approximately 10" from centerline when the problem arose. The core in this area just peeled out with the outer skin and upon further inspection it was apparent that all of the surrounding core was delaminated from the inner skin. By sounding and probing I estimate that the area of delamination may be about 2' square (if not more) starting about 5" from centerline extending outboard 2' and extending 1.5' forward from the aft end of the keel. By the way, the outer skin is very thick at just over .25" in this area. I guess cutting the skin and removing the core is the easy part (lol), but before I do I want to make sure that I am not "over aggressive" in my attack of this area.

It would seem the best end result would be achieved by removing the outer skin and core contiguously in the entire area of delamination then recore and glass in that section. However, I don't want to cut away a large part of the outer skin only to find the hull sinking down around me. My thought is that the solid glass along the centerline of the boat together with the stringers glassed into the inner skin should be sufficient to allow for this but I am skeptical! I have heard of people removing large areas of outer skin and core but I don't recall anything this close to centerline.

Has anyone removed the outer skin and coring around the keel? Will the inner hull support the boat regardless of the area of outer skin that is removed or what is a reasonable guideline? Any ideas, previous experience or guidance would be appreciated as I will continue to grind and cut away at the hull over the next week.


[This message has been edited by Breezin454 (edited 12-12-2008).]

Check out the following link where Rauzer II had some major core replacement work done... https://j30.us/ubbthreads/ubbthreads.php/topics/1864/Hot_Vac_Hull_Drying_Anyone_tri.html#Post1864

They cut out a section approximately 2 feet wide by 3 feet from the keel outboard, skipped 2 feet and cut out another section. When those 2 sections were glassed up, they moved the stands and did the sections they previously skipped. I have some photos, but do not know how to post them.
If you are doing a section 2 foot square or a little larger, I don't think you will have any problem with the boat crumbling around you.
Rauzer II #448

[This message has been edited by alcal1750 (edited 12-12-2008).]

You can host the pictures on a free photo site such as Picasa , Snapfish , Kodak etc., and post the link here, or put them in a zipped file and email them to me and I can host them on the J30 server.

[This message has been edited by Rhapsody #348 (edited 12-12-2008).]

I looked at the link provided and it sounds like your issue was very similar to mine. Any way you can get pics to me either directly to my email address or to the site as Rhapsody has suggested would be greatly appreciated. Can you also elaborate on the source of the leak? I know that everyone usually identifies the transom as the source of starboard side moisture but the core samples I pulled from my transome are bone dry. I have suspected the area under the cooler and the bilge. Where did this "repair sealant" leak exactly? It sounds as if it was at the leading edge of the keel. Based on some cracks in the area I suspect mine is at the trailing edge of the keel but I thought the center section of the hull was solid glass so I dismissed the idea that the leak could be in the area of the bilge.