• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Cracked fuel tank near sump...weld or sealant?

A

adamgrenda

Registered User
King Salmon, AK
Stock 18 gallon tank on experimental cub.

I’ve been trying to find where a small blue stain has been coming from for a few days now and finally found the problem. It’s a crack on the right tank at the sump and is barely seeping out any fuel.

I live in a pretty remote part of Alaska and don’t want the down time of sending the tank to Atlee to be welded. Can I have a local aluminum welder fix it? Are there any tricks to it?

Planning on pulling the tank after I drain it and fill it with water for him to weld.

Also thought of trying proseal or some other type of sealtant. Thoughts on that?



A994B485-900B-4EF9-A181-47CEC654A427.jpgD5B86C7F-8BE0-416B-A0D7-0CFDE7675F8D.jpg
 

Attachments

  • D5B86C7F-8BE0-416B-A0D7-0CFDE7675F8D.jpg
    D5B86C7F-8BE0-416B-A0D7-0CFDE7675F8D.jpg
    30.5 KB · Views: 237
  • A994B485-900B-4EF9-A181-47CEC654A427.jpg
    A994B485-900B-4EF9-A181-47CEC654A427.jpg
    42.2 KB · Views: 176
A simple repair for a qualified welder.
if he’s not familiar with welding on fuel tanks you’ll be buying a new tank, he’ll be putting a new roof on his shop.

looking at the photo, doesn’t look like a crack but edge of a cold weld.
there’s no reason for it to crack there.
I’ll probably get flamed for this but I carry JB weld in my tool kit for “temporary” repairs such as that.
 
Last edited:
Run the exhaust from your truck or fill with water. Just make sure it is very clean and should weld up no problem. ProSeal will work but eventually it might work and start leaking again.
Here is mine. Someone used Stratoflex hose for the fuel line into he tank. Not much flew and a real bear to get off.
20141015_163606.jpg
Cleaned up.
20141015_170754.jpg
Welded up.
20141015_191027.jpg
 

Attachments

  • 20141015_163606.jpg
    20141015_163606.jpg
    147.6 KB · Views: 980
  • 20141015_170754.jpg
    20141015_170754.jpg
    151.8 KB · Views: 1,135
  • 20141015_174536.jpg
    20141015_174536.jpg
    44.5 KB · Views: 143
  • 20141015_191027.jpg
    20141015_191027.jpg
    54.2 KB · Views: 979
Pro seal is fine. That’s what seals the rivets on Atlee tanks. Used many times to get by. Welding would be better, sure.


Sent from my iPhone using SuperCub.Org
 
Water makes a bit of a mess, purge with argon slowly from the bottom up.
argon is heavier and will displace air. You can also use argon to pressure test it, if it leaks you won’t have to purge again.
 
I have welded up a lot of tanks from boats, cars, motor sports and planes. I always let them air out overnight then run a hose from the truck exhaust into the tank or run an argon purge into it. Easy fix for anyone that is good with a TIG on Aluminum.
 
Back in my motorcyle days I saw many gas tanks welded.
Usually got sloshed out with water & dishwashing detergent,
then drained & welded.
Don't recall any argon or CO purging.
But that sounds like a good idea.
 
YouTube “alumaweld brazing process”
done with an oxy acet torch. (Still need to purge)
ive tried it on thin aluminum, typically lap joints.
im sure it would work well where structure is not an issue.
Though they claim it’s as strong as aluminum.
Custom bike builders use it to join two halves of hand formed gas tanks where conventional tig process would warp all their hard work.
Back to JB weld:
An old AC mechanic once told me, whenever in doubt, run it thru the “what’s the worst thing that could happen” test.
Drain the tank (or tilt the plane) so no weep, prep the area well, smear JB (or similar) over the crack, let it cure and go flying.
Whats the worst that could happen? - starts weeping and you have to pull the tank and weld it?
 
Thanks for all the responses guys. I have a aluminum fabricator/welder who is going to weld it up this week. Got the tank out and thanks to steves step by step instructions. Hope it goes back in with ease...any tips?
 
thinking back to some that were repaired at atlee's, they cut off drain bung and welded small section on top then welded new bung on..... not sure that's necessary.....
 
mike mcs repair said:
Pro seal is fine. That’s what seals the rivets on Atlee tanks. Used many times to get by. Welding would be better, sure.


Sent from my iPhone using SuperCub.Org
Click to expand...
Anyone know the sealing differences between Proseal and Flamemaster B 1/2?
 
Yeah, B 1/2 is the shortest cure time. When I search Proseal vs. Flamemaster I show 2 different products with Proseal being much more expensive.
 
Adamgrenda, any chance you could shoot a couple of pics of your tank bay before you put that back?? I’ve got a similar repair coming up (right along with warm weather!) Also, do you have an aluminum cover, or will you be putting fabric back?
 
You must log in or register to reply here.

Similar threads

aviationinfo
Atlee Fuel Tank Leak Repair
Replies
19
Views
7K
mike mcs repair
mike mcs repair
Jake
Fuel System help!
Replies
9
Views
4K
PA12Tray
PA12Tray
Floatin_around
Pa-16 Clipper fuel tank question
Replies
5
Views
3K
Steve Pierce
Steve Pierce
Marty57
Fuel tank design questions
2
Replies
47
Views
18K
Marty57
Marty57
algonquin
Urine colored fuel
Replies
8
Views
4K
King Brown
K
Back
Top