how to approach a bad thru-hull job by boat yard

[rgranger]

Thanks to all who replied.

Today I met with the guy who did the work. He explained that the smaller 1 5/8" plastic thru-hull that he removed had been pushed inside the remains of a 2" plastic thru-hull that had been recessed to be flush with the hull. He did not discover this until he bored the new hole and the old plastic flange pushed out: the old sealant had hidden the seam. He insists that he did not cut below the gel coat. The crater was already there. He did the best he could to bring the new bronze thru hull flush and fill and seal around it. I got a good vibe from him and believe he was being honest. Anway, as some of you pointed out, even if I thought he was telling a fiction, it's a pretty good story, and so taking this further would not be worth the time, money, aggravation and friction.

So this one is on me. I will do what I can to finish sealing the area and prevent osmosis. I am pretty sure I can make it work. The installation seem solid enough aside from the exposed layer or two of glass. The hull is quite thick at that spot.

Thanks again to all.

Sounds like a win!
Go sailing

 

[JoeWhite]

The best way to enlarge an existing hole is to use 2 holecutters both placed into eachother on the same drillbit with smaller holecutter the size of the existing hole and the outer larger one the size of the larger hole. The smaller holecutter will keep the larger cutter in position to cut the new hole. Experiment on a piece of wood first and insert the through hull to make sure you have the right size hole cutter.

 

[cdarwincole]

Hey, that's a neat idea, Joe. Thanks so much. I'd have to look at my hole saws and see if I could get the guide bit through two, but from what your're saying, it can be done. Didn't think of it. Too late for this job, but next time -- if there is a next time....LOL

I realize now that I should have done this job myself. I used to do it all. I've rebuilt a keel, rebuilt an interior, rebuilt an Atomic 4 engine, done all sorts of other boat rebuilding stuff (I am now rebuilding the transom of a Cape Dory 14 -- my launch) always figuring it out as I went along. I do damn fine work as eternal novices go.

Thing is, once I had discovered that recess in the hull for the old flange, I would have probably spend hours rendering it inconsequential. Sure, the new thru-hull would have sat above a smooth, uninterrupted skin as if on a new boat. But I would have lost time I need for numerous other projects on this boat and around the house. (Gotta keep the Mrs. happy, and boat work does not qualify.) So with my sail business doing well, limited time and lots of other projects , I though I'd farm this job out.

This Tripp 37 is a great old boat with good bones but in need of a work -- much of it cosmetic but a few tweaks for better perfomance, too.

This boat has an aluminum frame and grid and divinycell foam core hull -- really quite a masterpiece of construction from the pre-carbon fiber age. On either side of the keelson, the builders left a gap of several inches before the sandwich construction began. It's thick, solid glass there to avoid issues with thru hulls, and that's where this thru-hull is. The difficulty is that the hole had to be smack-dab center so the nut would fit in the narrow space.

Yeah, I could have done it. That and a million other things....LOL

Thanks again, Joe! Thanks everyone!

Cheers!

 

[Kings Gambit]

Thanks to all who replied.

Today I met with the guy who did the work. He explained that the smaller 1 5/8" plastic thru-hull that he removed had been pushed inside the remains of a 2" plastic thru-hull that had been recessed to be flush with the hull. He did not discover this until he bored the new hole and the old plastic flange pushed out: the old sealant had hidden the seam. He insists that he did not cut below the gel coat. The crater was already there. He did the best he could to bring the new bronze thru hull flush and fill and seal around it. I got a good vibe from him and believe he was being honest. Anway, as some of you pointed out, even if I thought he was telling a fiction, it's a pretty good story, and so taking this further would not be worth the time, money, aggravation and friction.

So this one is on me. I will do what I can to finish sealing the area and prevent osmosis. I am pretty sure I can make it work. The installation seem solid enough aside from the exposed layer or two of glass. The hull is quite thick at that spot.

Thanks again to all.

Repair of old boats is like repair the old house. Once you begin, you do not know what you will uncover. You may not, likely not, find a replacement item that works, etc. A “weekend” repair can easily turn into a multi-weekend one while you hopeless ponder a solution.