We had a fuel leak from the starboard tank (we thought) our tug is a 2007 37 hull 181. The leak was small and only occurring when the tanks were full. After inspection with a scope camera under and behind (hull side) found that the leak was coming from the hose clamps on the fill hose at the tank. Using about 4 feet of extensions on a socket wrench I was able to tighten the clamps and have not experienced any further leaks for the past 3 years. So you may want to check all clamps for tightness as well Regards Torben Mann Yes Dear IV Anacortes WA 37-181 > On Apr 19, 2024, at 13:05, sentoa-request@lists.sentoa.org wrote: > > Send Sentoa mailing list submissions to > sentoa@lists.sentoa.org > > To subscribe or unsubscribe via email, send a message with subject or > body 'help' to > sentoa-request@lists.sentoa.org > > You can reach the person managing the list at > sentoa-owner@lists.sentoa.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Sentoa digest..." > > Today's Topics: > > 1. Re: 2007 NT37 - Fuel tanks (Carmine Petracca) > 2. Re: 2007 NT37 - Fuel tanks (Michael Russell) > 3. Re: 2007 NT37 - Fuel tanks (Tom Krahn) > 4. Re: 2007 NT37 - Fuel tanks (Lee Tuthill) > 5. Re: 2007 NT37 - Fuel tanks (Tom Krahn) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 14 Apr 2024 10:33:47 -0700 > From: Carmine Petracca <petracca@lewiston.com> > Subject: [Sentoa] Re: 2007 NT37 - Fuel tanks > To: "South East Nordic Tugs Owners' Association (SENTOA)" > <sentoa@lists.sentoa.org> > Message-ID: <B8E2538D-A722-4C5D-A57C-48E7D1C27774@lewiston.com> > Content-Type: text/plain; charset=utf-8 > > If the leak were from an outboard seam, I would think that an access hole could be cut from the inboard side and the leak repaired. Obviously locating the leak is the first order of business. > Best of luck, I don’t envy you with this problem, but I think it can be solved easier than replacing the tank. > Carmine Petracca > Sleepless, NT32-86 > Anacortes, WA > >> On Apr 14, 2024, at 9:52 AM, Steve Day via Sentoa <sentoa@lists.sentoa.org> wrote: >> >>  >> Hi all, >> My NT37 has developed a fuel leak from the starboard side tank, it is unclear where the leak is coming from, all the fittings have been checked and all are dry. My fear is that it is coming from behind the tank, and possibly from one of the seams. >> >> Anybody had similar problems or know of any possible causes of the leak?. If it is a problem with one of the seams then I see no alternative other than removing the tank by cutting it up in situ and replacing with 3 or 4 smaller tanks linked together, not a job for the fainthearted.... >> >> Any thoughts would be welcome and appreciated. >> >> Steve >> SINBAD - NT37-192 >> Harwich UK >> >> >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > ------------------------------ > > Message: 2 > Date: Sun, 14 Apr 2024 17:14:11 -0700 > From: Michael Russell <maruss386@gmail.com> > Subject: [Sentoa] Re: 2007 NT37 - Fuel tanks > To: "South East Nordic Tugs Owners' Association (SENTOA)" > <sentoa@lists.sentoa.org> > Message-ID: <2A6A14D9-7591-4D01-8623-B932A100175B@gmail.com> > Content-Type: text/plain; charset=utf-8 > > I had the same problem with my NT39. Water in the tank accumulates in the foreword end and eventually causes pinhole damage. The fix was to cut an access hole in inboard side then clean the tank and seal it. This is best done by pro. The fix worked but it takes a lot of “boat bucks”. > Sent from my iPhone > >> On Apr 14, 2024, at 10:34 AM, Carmine Petracca via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> If the leak were from an outboard seam, I would think that an access hole could be cut from the inboard side and the leak repaired. Obviously locating the leak is the first order of business. >> Best of luck, I don’t envy you with this problem, but I think it can be solved easier than replacing the tank. >> Carmine Petracca >> Sleepless, NT32-86 >> Anacortes, WA >> >>>> On Apr 14, 2024, at 9:52 AM, Steve Day via Sentoa <sentoa@lists.sentoa.org> wrote: >>> >>>  >>> Hi all, >>> My NT37 has developed a fuel leak from the starboard side tank, it is unclear where the leak is coming from, all the fittings have been checked and all are dry. My fear is that it is coming from behind the tank, and possibly from one of the seams. >>> >>> Anybody had similar problems or know of any possible causes of the leak?. If it is a problem with one of the seams then I see no alternative other than removing the tank by cutting it up in situ and replacing with 3 or 4 smaller tanks linked together, not a job for the fainthearted.... >>> >>> Any thoughts would be welcome and appreciated. >>> >>> Steve >>> SINBAD - NT37-192 >>> Harwich UK >>> >>> >>> _______________________________________________ >>> Sentoa mailing list -- sentoa@lists.sentoa.org >>> To unsubscribe send an email to sentoa-leave@lists.sentoa.org >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > ------------------------------ > > Message: 3 > Date: Sun, 14 Apr 2024 21:24:01 -0400 > From: Tom Krahn <2baddad@gmail.com> > Subject: [Sentoa] Re: 2007 NT37 - Fuel tanks > To: "South East Nordic Tugs Owners' Association (SENTOA)" > <sentoa@lists.sentoa.org> > Message-ID: > <CAMK+aL=Rks=uhU2oXH6Ee9pHMZc0SAVbjSX2FiCoEu1VzB06KA@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > We had a fuel tank leak. It was very slow and very, very hard to find. > We eventually localized the leak to the front portion of the tank. > > We considered the possibility of cutting the tank into pieces and > removing it, but the space was too cramped (in the 32) for any of the > people who worked on our boat to feel safe doing that. > > We considered first cutting a porthole in the tank to inspect and clean > it, lining the tank, and/or replacing the tank with bladder(s). We decided > against those for various reasons. > > So we decided to get a whole new tank. To do this a hole needed to be > cut in the topsides, the tank removed, a new aluminum tank installed, > and fiberglass work done to repair the hole. The result was great. You > can’t see where the hole was cut. > > Once the tank was removed, it was examined. The leak was due to the > bottom seam of the tank rubbing against the forward bulkhead, just above > the stringer. A small pinhole developed. I think this may be a design > flaw. > > Tom Krahn > Diana B. > 32-285 > Barrington, RI > > ------------------------------ > > Message: 4 > Date: Fri, 19 Apr 2024 15:44:50 -0400 > From: Lee Tuthill <lbtuthill@gmail.com> > Subject: [Sentoa] Re: 2007 NT37 - Fuel tanks > To: "South East Nordic Tugs Owners' Association (SENTOA)" > <sentoa@lists.sentoa.org> > Message-ID: <6B157B4A-0CAF-404B-A573-A5B3E2A32A19@gmail.com> > Content-Type: text/plain; charset=utf-8 > > Steve, > > A year ago at launch I found about two quarts of diesel fuel in my tank room bilge. I had not checked the bilge before launch. After cleaning it up and suspecting it had come from starboard tank, I used a pole to push several rolled up absorbent pads in behind the forward end of the tank along the hull. The first removal brought some residual diesel and what looked like initial manufacturing debris. After placing a second set of pads back along outboard side of tank, I monitored them and found no additional diesel. What next?? > > As part of winterizing Encore I get a gerry jug with about a gallon of diesel to use in filling respective fuel filter replacements. Remaining diesel was poured into the starboard tank. Could that hav been the source? Was there a possible leak in the fill part of the tank? I had not added fuel in over a year. I went from the North Channel to the southern end of Georgian Bay (Ontario) to a large marina that had the equipment to pressurize the system. We totally isolated all parts of tank and fill pipe, closing all flow valves to and from engine and sight gauges. The test was done with 2+ psi for14 hours. There was zero pressure drop over those 14 hours so we decided to just go cruising. I did add fuel while at that marina to about half full and had no leakage during that process. I continued to leave new, rolled up absorbent pads behind the tank and at haul out, found no sign of diesel leakage. The mystery remains and when we launch boat this spring we certainly hope to find no fuel in the bilge. > > During this entire process, Dave Allen at NT was very helpful with suggestions that included replacement of the tank. As a starter for that major undertaking, the water tank would need to be removed to allow maneuver room for the removal and replacement of the starboard tank. There had been discussions of cutting a hole in the tank and trying to find the leak and then sealing it with special sealant but the difficulty in my mind was just how to find the leak source and then the issue of reliability of sealing it from the inside. > > Our NT 37 is hull number 190, (compared to your 192) which raises the question about a possible manufacturing defect in the tanks which were made so close to each other time wise. Please keep me posted on your eventual solution. > > Lee > ENCORE,NT37 FB, 190. > Exeter, RI, but currently in northern Lake Huron. > >> On Apr 14, 2024, at 12:51 PM, Steve Day via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> Hi all, >> My NT37 has developed a fuel leak from the starboard side tank, it is unclear where the leak is coming from, all the fittings have been checked and all are dry. My fear is that it is coming from behind the tank, and possibly from one of the seams. >> >> Anybody had similar problems or know of any possible causes of the leak?. If it is a problem with one of the seams then I see no alternative other than removing the tank by cutting it up in situ and replacing with 3 or 4 smaller tanks linked together, not a job for the fainthearted.... >> >> Any thoughts would be welcome and appreciated. >> >> Steve >> SINBAD - NT37-192 >> Harwich UK >> >> >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > ------------------------------ > > Message: 5 > Date: Fri, 19 Apr 2024 16:04:58 -0400 > From: Tom Krahn <2baddad@gmail.com> > Subject: [Sentoa] Re: 2007 NT37 - Fuel tanks > To: "South East Nordic Tugs Owners' Association (SENTOA)" > <sentoa@lists.sentoa.org> > Message-ID: > <CAMK+aLm+Z9+fPrT0s_KkwrVAay6y164mRMK5xqf-o0X15XsLqQ@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > I'm sorry if this is a repost, but it didn't seem to post last time. > I've had email problems. > > We had a fuel tank leak. It was very slow and very, very hard to find. > We eventually localized the leak to the front portion of the tank. > > We considered the possibility of cutting the tank into pieces and > removing it, but the space was too cramped (in the 32) for any of the > people who worked on our boat to feel safe doing that. > > We considered first cutting a porthole in the tank to inspect and clean > it, lining the tank, and/or replacing the tank with bladder(s). We decided > against those for various reasons. > > So we decided to get a whole new tank. To do this a hole needed to be > cut in the topsides, the tank removed, a new aluminum tank installed, > and fiberglass work done to repair the hole. The result was great. You > can’t see where the hole was cut. > > Once the tank was removed, it was examined. The leak was due to the > bottom seam of the tank rubbing against the forward bulkhead, just above > the stringer. A small pinhole developed. I think this may be a design > flaw. > > Tom Krahn > Diana B. > 32-285 > Barrington, RI > >> On Fri, Apr 19, 2024 at 3:45 PM Lee Tuthill via Sentoa >> <sentoa@lists.sentoa.org> wrote: >> >> Steve, >> >> A year ago at launch I found about two quarts of diesel fuel in my tank room bilge. I had not checked the bilge before launch. After cleaning it up and suspecting it had come from starboard tank, I used a pole to push several rolled up absorbent pads in behind the forward end of the tank along the hull. The first removal brought some residual diesel and what looked like initial manufacturing debris. After placing a second set of pads back along outboard side of tank, I monitored them and found no additional diesel. What next?? >> >> As part of winterizing Encore I get a gerry jug with about a gallon of diesel to use in filling respective fuel filter replacements. Remaining diesel was poured into the starboard tank. Could that hav been the source? Was there a possible leak in the fill part of the tank? I had not added fuel in over a year. I went from the North Channel to the southern end of Georgian Bay (Ontario) to a large marina that had the equipment to pressurize the system. We totally isolated all parts of tank and fill pipe, closing all flow valves to and from engine and sight gauges. The test was done with 2+ psi for14 hours. There was zero pressure drop over those 14 hours so we decided to just go cruising. I did add fuel while at that marina to about half full and had no leakage during that process. I continued to leave new, rolled up absorbent pads behind the tank and at haul out, found no sign of diesel leakage. The mystery remains and when we launch boat this spring we certainly hope to find no fuel in the bilge. >> >> During this entire process, Dave Allen at NT was very helpful with suggestions that included replacement of the tank. As a starter for that major undertaking, the water tank would need to be removed to allow maneuver room for the removal and replacement of the starboard tank. There had been discussions of cutting a hole in the tank and trying to find the leak and then sealing it with special sealant but the difficulty in my mind was just how to find the leak source and then the issue of reliability of sealing it from the inside. >> >> Our NT 37 is hull number 190, (compared to your 192) which raises the question about a possible manufacturing defect in the tanks which were made so close to each other time wise. Please keep me posted on your eventual solution. >> >> Lee >> ENCORE,NT37 FB, 190. >> Exeter, RI, but currently in northern Lake Huron. >> >>>> On Apr 14, 2024, at 12:51 PM, Steve Day via Sentoa <sentoa@lists.sentoa.org> wrote: >>> >>> Hi all, >>> My NT37 has developed a fuel leak from the starboard side tank, it is unclear where the leak is coming from, all the fittings have been checked and all are dry. My fear is that it is coming from behind the tank, and possibly from one of the seams. >>> >>> Anybody had similar problems or know of any possible causes of the leak?. If it is a problem with one of the seams then I see no alternative other than removing the tank by cutting it up in situ and replacing with 3 or 4 smaller tanks linked together, not a job for the fainthearted.... >>> >>> Any thoughts would be welcome and appreciated. >>> >>> Steve >>> SINBAD - NT37-192 >>> Harwich UK >>> >>> >>> _______________________________________________ >>> Sentoa mailing list -- sentoa@lists.sentoa.org >>> To unsubscribe send an email to sentoa-leave@lists.sentoa.org >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > > ------------------------------ > > End of Sentoa Digest, Vol 155, Issue 2 > **************************************