pressure testing tank

I have an idea I would like to bounce off others here.

Could one pressure test the tank skins and end rib integrity before closing out the rear bulkhead? It seems to me that one could partially submerge the tank, nose up, in water to about 2 ft. This would create approx .8 psi inside the tank. With this pressure, one could run a soap bubble test and find any leaks prior to sealing the bulkhead. Any leaks thus found could be easily fixed.

Just a thought. Please let me know if this makes sense. I have never tried it.

Cheers,

RL

If you're worried about leaks, the just build in access covers into the rear tank bulkhead for easy access/repair. Seems to be pretty typical in my experience that you're going to have to get inside in ~10 yrs or so to reseal. If you find one after completing the tank, open up the access cover and go after it with some ProSeal. Do each bay, or do one at a time. These are the end cover access assys from Vans. Not riveted, just screwed and prosealed.

Further thought on new tanks. If you're afraid of dealing with a leaker or two, then once you complete the riveting, smear a fillet down each side of the connected flange and over the protruding rivets. This will add a pound or two if you do this to all joints in both tanks. But if done right, you'll minimize the chances of having that leak appear from a lightly sealed spot one day just after you paint he plane.
And the only way you're going to do this to aft bulkhead is with the access covers shown in the pic below.

Access Covers

Bryan: Confirm please. Same cover as the one on the root rib? Which style nutplates did you use? Thanks.

Don B

RV 9 Rebuild in Progress

Leaks

The most common leak points on the 7,8 & 9 are the corners of the rear baffle. I suggest fay sealing the rear baffle with extra on the corners. I filled them in when the end ribs were installed to reduce the amount needed when the baffle was set. I also added a fillet on the outside edges of the baffle and end ribs. I used sealed platenuts so the access panel screws would not be a leak point.

cajunwings said:

Bryan: Confirm please. Same cover as the one on the root rib? Which style nutplates did you use? Thanks.

Don B

RV 9 Rebuild in Progress

Click to expand...

Yes, same as root covers. Std -8 nut plates. Have to split the back plate to get into the hole.