Odor through plastic fuel tank

[billandalita]

My boat is a 2002 Catalina MII, hull 1596.  Tank is plastic.  I have not noticed a diesel odor in the aft cabin; however, I do detect a diesel odor through the two forward small hatches in the lazarette that are over the tank outlet, fuel indicator and fuel return.  The odor is not so strong through a larger hatch in the lazarette that is approximately centered over the tank.  See http://c34.org/bbs/index.php/topic,4085.15.html.  I thought the odor might be coming from the fittings and fuel lines attached to the tank at it's forward end.  Now I am not so sure.  Perhaps fuel has indeed permeated the tank walls.  I intend to snug up some of the fittings next week to see if that helps.  Bill

[Roc]

Everyone,
So far, only a few have an odor problem.  I was hoping there would be more so Catalina would see a broad based issue, this way maybe a discount cost can be extended to everyone.  Please post on this thread if you are willing to change your tank ($$ ?)due to diesel permation smell through the walls.  I can then gather the hull numbers and talk to Catalina.

[Jim Hardesty]

Roc,
I responded as having a problem with the fuel tank odor.  I spent a few hours on the boat to day and did some trouble shooting.  The boat has been covered and shutup for three weeks.  I removed the partition to the tank and put my nose right to the tank, didn't get an odor.  I now think that the odor is comming from the running engine, possible from the airfilter  or what they pass off as an airfilter.  Or possibly the odor is stronger when warm, it's been mid 30's to mid 20's for a couple of weeks.  So, now I am not so sure that the odor is from the tank.
Take me off the list that has a tank problem.  I may have it, but want to trouble shoot it more.  I am going to buy another air filter and look over everything else.  If it is temp related I won't know till summer.
Sorry for the false response.  I thought if many others had a problem I did to.

Regards,
Jim Hardesty
2001 hull # 1570

[Roc]

Jim,
I am pretty much convinced that my issue is a permeated tank wall.  I've search for leaks (bone dry), and the smell is definitely not diesel exhaust fumes.  It is clearly fresh diesel.  When I pull the panel to access the tank in the aft cabin, put your nose near the tank and it is very strong.  The smell gets strong at times in the aft cabin (smell of raw diesel).  Also, when new, I remember being able to see the level of fuel in the tank. Now the tank is an opaque copperish color.  Can't see through it.

[Stu Jackson]

Have you folks tried getting in touch with Peggie Hall?  She's the renown expert on boat odors, including heads and, most importantly, plastic tanks.  You can find here at www.catalinaowners.com, find the Forums tab at the top and click on expert forums, then The Head Mistress.  She may be able to help on understanding whether the tanks have issues.  You may have to join that forum to post, but it's a worthwhile board in addition to this and the C36 'site MB.

[Jim Hardesty]

Roc,
I have the panel off to run some wires.  I put a spot light on the tank and I can see thru the wall, at least on the top down to the fuel level.  When I cup my hand to the tank and put my nose to it I do get a faint odor, hard for me to identify but must be diesel.  This is with the winter cover on and the outside temp. at 24 deg.  Think that I'll leave the cover off till we get some warmer weather and see if the odor is stronger.

[dhagen]

Mine is a 2001, hull number 1592.
Dan Hagen

[Stu Jackson]

Dan was thoughtful to contact Peggie, see: http://forums.catalina.sailboatowners.com/showthread.php?t=108780

I alerted Peggie to this topic when Dan brought it up over on co.com, and she pm'ed me back with this: 

Interesting thread, Stu. It appears the problem may be limited to specific production years. I'm fairly confident that the tanks are the right kind of PE--crossed-linked--but wall thickness matters too...and I wonder if Catalina's supplier during those years made the walls too thin. It would certainly be worthwhile to know the wall thicknesses of problem tanks vs the years that don't seem to be a problem. If there is a big difference in the thickness--or even the tank materials--used during those years, there could be grounds for a class action if Catalina isn't willing to replace the tanks.

[dhagen]

Thanks Stu.  I hadn't seen this and left Peggy a note on the other forum.  Are you aware of any easy way to measure the thickness of the tank wall?
Dan

[Roc]

It would be better if there were a bunch of people coming back with strong fuel odors, with all respondents having similar hull #'s.  Then there could be something happening as Peggy said.  But two or three people doesn't look like a class action suit.

[Stu Jackson]

...any easy way to measure the thickness of the tank wall?

Easy?  Nope.  Any...hmm.  Seriously, no, but some of our engineering buddies here might.  I'm sure something with refraction, reflection and smoke and mirrors...

[Ken Juul]

 To get a rough idea you could use one of these to measure the thickness of the top thru the fuel level sensor opening.  Suggest on with a deep reach to get past any build up for sensor attachment.

http://www.brandsplace.com/0384-fow72-234-402.html