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New tank is blowing soap bubbles

AeroDog

Well Known Member
Friend
After inflating the balloon, I discovered bubbles in four places. All the threads I could find with the search function discussed repairing tanks which have had fuel in them, and the overwhelming consensus is that these leaks must be repaired from within. I'm certainly hoping I don't have to open this tank up to do the repairs. The build manual simply says to fix the leaks and re-check. Any advice will be appreciated.

Jerre
 
Tank repair

Jerre
I've heard of builders pulling a vacuum on the tank then applying thinned proseal or other thin sealant.
The other option is cutting access holes in the baffle, sealing then installing covers. One of our Colorado RV builders did it recently.
 
Jerre,
Sorry to here about the leaks but a little more specific about where the leaks are on the tank. IE around a rivet, on a seam, or a screw?
Larry mentioned the vacuum method and I too have heard of it but never tried it myself or know anyone who did it. I?m also interested in what would used to thin the sealant or what other type of sealant might be used.

Without seeing where the leaks are occurring if it were a around a rivet I would consider removing it and resealing. On a seam I would try cleaning off exposed sealant and use a blade clean as best you can between the pieces and reseal. And around a screw, clean it off, back it out, reseal and put it back in.

None of it?s simple but it is definitely better to address it before fuel is in the tank.
 
Jerre
I've heard of builders pulling a vacuum on the tank then applying thinned proseal or other thin sealant.
The other option is cutting access holes in the baffle, sealing then installing covers. One of our Colorado RV builders did it recently.

Sealant is available that is thinner. Search for 890A2 instead of 890B2.
 
Jerre,
Sorry to here about the leaks but a little more specific about where the leaks are on the tank. IE around a rivet, on a seam, or a screw?
Larry mentioned the vacuum method and I too have heard of it but never tried it myself or know anyone who did it. I?m also interested in what would used to thin the sealant or what other type of sealant might be used.

Without seeing where the leaks are occurring if it were a around a rivet I would consider removing it and resealing. On a seam I would try cleaning off exposed sealant and use a blade clean as best you can between the pieces and reseal. And around a screw, clean it off, back it out, reseal and put it back in.

None of it?s simple but it is definitely better to address it before fuel is in the tank.

Two leaks are in the rear corners (one upper, one lower). A third is in the center of a rivet (one that's suppose to be "solid.") The fourth is at the fuel return fitting.
 
been there

Jerre
I've heard of builders pulling a vacuum on the tank then applying thinned proseal or other thin sealant.
The other option is cutting access holes in the baffle, sealing then installing covers. One of our Colorado RV builders did it recently.

Been there, done that. Pulled a small vac, sucked in proseal and let cure. I did not thin the proseal and my tanks never had fuel in them. YMMV
 
With the newly-built tank dry of fuel and on your workbench, you will never have a better time to correctly address your leaks. Remove the forward access panel* and fix the leaks from within. Like a roof leak, sometimes the visible external evidence doesn't truly reflect the actual location of the leak. So think like a leak!

*Removing the access panel isn't that onerous a task. Use a thin flexible putty knife to carefully separate the panel from the tank; then thoroughly clean off the old sealant before reattaching the panel with fresh sealant.
 
Disassembly

With the newly-built tank dry of fuel and on your workbench, you will never have a better time to correctly address your leaks. Remove the forward access panel* and fix the leaks from within. Like a roof leak, sometimes the visible external evidence doesn't truly reflect the actual location of the leak. So think like a leak!

*Removing the access panel isn't that onerous a task. Use a thin flexible putty knife to carefully separate the panel from the tank; then thoroughly clean off the old sealant before reattaching the panel with fresh sealant.

I saw men in Mexico remove windshields and similar parts using a guitar "E" string. The big windshield company uses a similar device. Some sort of high tensile string.
 
Jerre -

+1 for removing the access plate and doing the repair from inside the tank. You will feel better knowing it is not a patch from outside the tank.

You may want to consider the careful use of a heat gun on the access panel. The heat will help soften the proseal ... making it a little easier to get a blade, putty knife or tool of your choice between the access panel and tank body.
 
Second the advice for the A2 sealant. I got some from www.skygeek.com, which has a nice variety of tank sealants.

This first picture shows the general approach and sizing for sealant. The second photo shows how to overcoat seams and potential leak points. Basically, it adds the suspenders to the belt for more sealing security.

pWCAWuc.jpg



oNhnbQV.jpg


Dave
 
The Mothership said to take the access plate off and seal from within. I'm going to temporarily seal from outside just to continue a thorough leak test, then take the E string off my Taylor and try that method for removing the plate (needed new strings anyway). Thanks again for all the help.

Jerre
 
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