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Bob Hoffman

Well Known Member
I was crawling around under the wing when I notice that a flush rivet smack in the center of of the fuel tank is weeping a fair amount (the tel-tale blue/green stain all the way to the trailing edge). Has anyone had this problem and how do I fix it ???. I already drained the tanks in anticipation of doing the Vans pickup tube thing sooo I'm ready to go.
Thanks
Bob
 
Same Problem

Hey,

I had the same issue. A very small weep that was barely noticeable. After some research I opted to drill out the rivet, redrill with a #30 and used a pop rivet with lots of proseal on it. Before pulling the rivet I used piece of 1/16th inch wire and put some proseal in the hole.

Nearly 50 hours without any problems. The Loctite method seemed like a bandaid fix to me.
 
Had the same problem. Drilled it out for a structural pop rivit. Used the caulk gun pro seal and squeezed some pro seal into the hole. Gooped the rivit and squeezed it. No problems since. If you have the pro seal that you only mix the amount you need I think you could take some wax paper and do something like cake decorators do and fold the paper so that you have a small opening and squeeze the pro seal into the hole. You will have a rivit size area to patch with paint.
 
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Thank's everyone
I tried the Locktite 290 self wicking (thought I'd try the least invasive first) BTW If anyone "tries this at home" be careful when creating the vacume in the tank -- you can dammage the tank beyond repair (did I say least invasive??) it doesn't take much .I used my wifes house vacume but you still need an opening somewhere (I used the drain plug hole) to control the amount of vacume.
Now I will pressure test this week
 
Bob Hoffman said:
Thank's everyone
I tried the Locktite 290 self wicking (thought I'd try the least invasive first) BTW If anyone "tries this at home" be careful when creating the vacume in the tank -- you can dammage the tank beyond repair (did I say least invasive??) it doesn't take much .I used my wifes house vacume but you still need an opening somewhere (I used the drain plug hole) to control the amount of vacume.
Now I will pressure test this week
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I'd be VERY reluctant to use a vacuum cleaner to pull a vacuum on any kind of fuel tank!!
If gas vapors got to the electric motor in the vacuum you could have one big explosion and fire! I'd only use a hand pump for something like this.
 
Good point
I neglected to say that my tanks are off the wings and completly clean of fuel and fumes.
Do be careful out there
 
drilled out rivets

OK, you got me curious now. For the guys that drilled the rivets out to replace them, what happens to the shop-head?
 
I'm going to have to put in a word of caution here. If there has EVER been fuel in a tank. It will NEVER be totally void of fumes. I have seen a model "T" gas tank that had been lying out in a field open for over 30 years. There was not a trace of gas or fumes, but guess what. When a welding torch was applied, it popped pretty loud expanding the sides of the tank. No one was hurt but several of us needed a change of underwear. Gasoline fumes get into the pores of the metal and stay there.
Mel...DAR
 
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Mel said:
I'm going to have to put in a word of caution here. If there has EVER been fuel in a tank. It will NEVER be totally void of fumes. I have seen a model "T" gas tank that had been lying out in a field open for over 30 years. There was not a trace of gas or fumes, but guess what. When a welding torch was applied, it popped pretty loud expanding the sides of the tank. No one was hurt but several of us need a change of underwear. Gasoline fumes get into the pores of the metal and stay there.
Mel...DAR
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Mel is ABSOLUTELY right! I grew up in a welding shop (We Make People Steel Things) and dad had many people come in with "clean" tanks needing welding. He had a collection of several dozen newspaper clippings about tank explosions. He always asked the customer to read through them, and then if they would sit on the tank, he would weld it. Never had any takers, as near as I can recall. We did chisel out the end of drum that had been empty for years (using grease so there would be no sparks) and he touched a torch to it from the side. It slid about four feet. NOTHING makes a gas tank safe, ever.

Bob Kelly
 
Mel said:
I'm going to have to put in a word of caution here. If there has EVER been fuel in a tank. It will NEVER be totally void of fumes. I have seen a model "T" gas tank that had been lying out in a field open for over 30 years. There was not a trace of gas or fumes, but guess what. When a welding torch was applied, it popped pretty loud expanding the sides of the tank. No one was hurt but several of us needed a change of underwear. Gasoline fumes get into the pores of the metal and stay there.
Mel...DAR
Click to expand...
This reminds me of a story my dad used to tell me of the technique for removing dents from gas tanks back when roads were rutted and substantial tank dents were common. The dent remover guru would drain the tank and then simply pass a torch over the open fill tube. The ensuing explosion would very effectively push the dent back out. He said most of the time the explosion would not rupture the tank!:eek:
 
welding aluminum fuel tanks

I had one of my PA-12 tanks welded by a certified aircraft welder about ten years ago. He rented a cylinder of CO2 and flooded the tank with a continuous stream of CO2 while he welded. It worked fine, as he said it would, but I remember standing back when he put the torch to it. Steve.
 
Comon'

You folks are scaring people. YES...be careful but....I worked in refining and chemicals for 30 years. How do you think gasoline/propane/etc is made?? It's made in distillation columns....yup..... a great big tall 'gas tank'. They don't last forever......and periodically are taken out of service for upgrades and repairs. During that time boilermakers and welders go in the columns with their torches and welding rods to make the needed repairs.

You folks are dead wrong....fuel tanks can and are made SAFE to work on everyday....period.

Rick in Ohio at the Buffalo Farm - RV6 sold, RV8 project completed, RV4 prepping for paint, RV10 and F1 Rocket under construction.....and I have welded on MANY a gas tank!
 
Tank Leak

Try some Seal-All by Eclectic Products. I did this on my old Piper fuel tank and when I sold it, it had 5 years and 587 hrs with no leaks. It dries almost clear, other people will not see it, you only need a spot about 1/8" bigger than the rivet. You only need to drain the tank, let the tank dry over night, I did not vacuum the tank, I gave it 1 day to dry.
Hope this helps.
Frank
 
Off topic but... The repairman that fixed my gas water heater a couple of months ago told me how they weld on full natural gas pipelines without purging. No oxygen, no fire. - Not the same as an aircraft tank of course, but it still takes guts. Right up there with lineman working on live high tension power lines while strapped to the skid of a helicopter.
 
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