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Author Topic: Cracked tank vent  (Read 130 times)

May 18, 2017, 09:38:54 PM
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Kindfreak

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Cracked tank vent
« on: May 18, 2017, 09:38:54 PM »
Repairing my boats fuel tank ground I noticed the vent tube that is welded to the aluminum tank seemed bent and I saw a crack in the aluminum tubing any ideas of the best fix I will remove and weld if I absolutely have to

May 18, 2017, 10:03:11 PM
Reply #1

Capt. Bob

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Re: Cracked tank vent
« Reply #1 on: May 18, 2017, 10:03:11 PM »
Can you slide the vent hose down enough to cover the crack in the tube? :ScrChin:

Capt. Bob
1991 210 Walkaround
1991 Yamaha 200
"Reef or Madness IV"

May 18, 2017, 10:08:06 PM
Reply #2

wingtime

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Re: Cracked tank vent
« Reply #2 on: May 18, 2017, 10:08:06 PM »
Cover it with the vent hose or just sand it and put some J B weld on it. Welding it is a big ordeal...  removing the tank. Draining ALL the fuel. Purging the tank with inert gas....  Yadda yadda....
1998 Explorer w/ Etec 250


1987 170 w/ Evinrude 90

May 18, 2017, 10:19:22 PM
Reply #3

Kindfreak

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Re: Cracked tank vent
« Reply #3 on: May 18, 2017, 10:19:22 PM »
Yeah it's been years since I bothered welding a tank and would honestly rather not do the yada yada again so I posted a photo of the crack in my gallery but also I was wondering if someone could tell me what gas line to buy and I tested my sending unit and it seems to work fine but would it not be wise to just replace its at the bend so I feel like the hose would need a 90deg bend to bypass the crack

May 18, 2017, 10:47:02 PM
Reply #4

Kindfreak

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Re: Cracked tank vent
« Reply #4 on: May 18, 2017, 10:47:02 PM »

May 18, 2017, 11:18:14 PM
Reply #5

Capt. Bob

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Re: Cracked tank vent
« Reply #5 on: May 18, 2017, 11:18:14 PM »
I'm thinking you have bigger problems than that crack. :ScrChin:

Capt. Bob
1991 210 Walkaround
1991 Yamaha 200
"Reef or Madness IV"

May 18, 2017, 11:20:25 PM
Reply #6

wingtime

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Re: Cracked tank vent
« Reply #6 on: May 18, 2017, 11:20:25 PM »
Whoa yeah I think you have bigger issues.
1998 Explorer w/ Etec 250


1987 170 w/ Evinrude 90

May 18, 2017, 11:22:59 PM
Reply #7

Kindfreak

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Re: Cracked tank vent
« Reply #7 on: May 18, 2017, 11:22:59 PM »
Would you care to elaborate

May 19, 2017, 01:00:55 AM
Reply #8

boatnamesue

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Re: Cracked tank vent
« Reply #8 on: May 19, 2017, 01:00:55 AM »
Yeah, I agree with the guys above. And im pretty sure they are implying you don't just have a cracked vent problem...you've got a corrosion problem.  If the corrosion I see in the picture is also located elsewhere on the tank you can expect a fuel leak at any time.  An aluminum tank should be silver, not brownish or white or any other color associated with corrosion.  That brownish color by the way is dried fuel.

Sure, you could slide a vent hose all the way down to tank, covering the vent crack.  But the area around the vent fitting weld is just as bad as the fitting itself.  Only a matter of time before corrosion eats through this area, at which point you're venting fuel under the deck....sitting atop a bomb, literally. 

Hate to be the bearer of bad news, but the issue is the tank not the crack in the vent.  Follow the link below.  I just had to replace my tank due to a fuel leak caused by corrosion eating 4 holes through the top of tank. 


https://classicaquasport.com/smf/index.php?topic=14273.0
---------------
Jason
1976 AS 170
1998 S115TLRW

May 19, 2017, 06:04:59 AM
Reply #9

Kindfreak

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Re: Cracked tank vent
« Reply #9 on: May 19, 2017, 06:04:59 AM »
Well I was hoping the oxidation was just accelerated because of the bad ground but sounds like I am taking a tank out tonight and inspecting it more thorough. Could you guys save me some home work and recommend poly vs aluminum ? Honestly I'm considering a wrecking ball and a deep hole at this point the boat is a 1982 19.6' aquasport with an evinrude vro 140 and lots of gel coat issues various deck rot and an owner that try's to fix to much

May 19, 2017, 08:21:48 AM
Reply #10

Capt. Bob

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Re: Cracked tank vent
« Reply #10 on: May 19, 2017, 08:21:48 AM »
Unfortunately, what you're see on top is an indicator that water has entered the tank coffin. Trapped against the bottom, between the tie down straps/foam tape or other spots between the tank and coffin, you'll find that the corrosion is as bad or worst. When the tank shifts (not if) usually when it is full and in an unsettled sea, the corrosion will break free and leaking begins. Sometimes slow, somethings fast.

That may be the original aluminum tank. You will know when you read the spec label on top. Poly tanks are available but you may not find one that has the same quantity or dimensions and might be harder to install. Aluminum is more expensive but can be built to your original size. Circa 80s 19-6 came with a 45gal. tank.

Good luck. :thumright:

Capt. Bob
1991 210 Walkaround
1991 Yamaha 200
"Reef or Madness IV"

May 19, 2017, 11:46:16 PM
Reply #11

boatnamesue

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  • Jason
Re: Cracked tank vent
« Reply #11 on: May 19, 2017, 11:46:16 PM »
Could you guys save me some home work and recommend poly vs aluminum ?

Once you've got the tank out measure its dimensions, L x W x H.  If the dimensions are common you can call around to marine surplus stores.  Most sell used tanks.  If the dimensions are uncommon, like my tank, your options are limited. 

Poly tanks are manufactured using a mold that has specific dimensions.  So if your tank dimensions are not available in poly you're other option is aluminum.  You'll then need a tank fabricator to custom build the tank.  I got 6 quotes for my tank, the majority came back with a cost of $13-$15/gallon.  I found a small busniess fabricator in Venice, FL.  He charged me $12/gallon and included a WEMA sender ($75 retail).  He turned the tank over in 4 days, while all other fabricators told me their turnaround was 10-12 days.  Let me know if you want my guys contact info. He did a great job. 
---------------
Jason
1976 AS 170
1998 S115TLRW

May 21, 2017, 08:05:03 PM
Reply #12

Kindfreak

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Re: Cracked tank vent
« Reply #12 on: May 21, 2017, 08:05:03 PM »

May 21, 2017, 08:09:01 PM
Reply #13

Kindfreak

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Re: Cracked tank vent
« Reply #13 on: May 21, 2017, 08:09:01 PM »



This tank seriously doesn't seem original to me but it's my first boat so yeah I just would think 30yrs of corrosion would be here

May 21, 2017, 08:22:42 PM
Reply #14

Kindfreak

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Re: Cracked tank vent
« Reply #14 on: May 21, 2017, 08:22:42 PM »
21.5" x 64" x 8" 47g so a 45gallon tank you sir know your stuff. so the well is 22" x 64" x 11" and this gas hasn't leaked out yet the bottom seams perfect aluminum thank you everyone for your help I am sure this boat and me are going to need couples thearapy for a few weeks if it's years