Rusted Out 1970 850 Spider Fix-Up

Aahhhh ...such a cute little engine and tranny. Anyone ever built a go-cart around one?

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And look...here is my precious now! So glad to see it again. I think it is giving me the finger. I rinsed it out a bit, and hardly anything came out! Probably already dissolved into that gas I drained. Since the weather has gotten yuckier, and I want this to dry out, we will cut it open in a few days. Unless I get impatient.

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You might want to try a concentrated OxiClean and hot water. I could not believe the crap it took out. The first application got about 95% of it, and after a second treatment it was all shiny metal inside.
 
You might want to try a concentrated OxiClean and hot water. I could not believe the crap it took out. The first application got about 95% of it, and after a second treatment it was all shiny metal inside.
I may give it a try. I am leaning towards a lot of the crap already being dissolved with the 4 gallons of gas I put in there. Thinking about sloshing two gallons of gas around, filtering and repeating until clean. Heaven knows it has shown that gas can dissolve this crap!
 
I may give it a try. I am leaning towards a lot of the crap already being dissolved with the 4 gallons of gas I put in there. Thinking about sloshing two gallons of gas around, filtering and repeating until clean. Heaven knows it has shown that gas can dissolve this crap!
It took about a week for the gasoline that I put in my supposedly clean tank to dissolve enough of the crud to send it to my carbs. After I drained the tank and discovered where all this stuff was hiding, it became clear that it would take something stronger (and safer) than gasoline to remove it in any reasonable period of time.
 
Daniel, PLEASE DON'T half fill the tank with gasoline. TOO DANGEROUS! Better full or don't use anything explosive. It's the vapors and air that are dangerous, not the full liquid. SAFETY FIRST!!!!!!!
 
Daniel, PLEASE DON'T half fill the tank with gasoline. TOO DANGEROUS! Better full or don't use anything explosive. It's the vapors and air that are dangerous, not the full liquid. SAFETY FIRST!!!!!!!
I appreciate the concern, but how is sloshing a gallon of gas around in a gas tank dangerous? Certainly no welding or cutting will take place during these procedures. I am serious when I say, please tell me your concerns.
 
Hi Daniel,
Gas fumes explode at around 13:1 ratio. In a partly filled tank it's easy to get this mixture/vapor ratio. Boom. Gas fumes can travel 20-30 feet from the source and "fire" back to the tank. Hot water heaters are great for this as they are often in the garage. I've actually seen small leaks welded on the car with a totally full tank of gas. If it's an open bucket you get a big "woosh" and fireball. IF ENCLOSED WITH A SMALL OUTLET you have a combustion chamber or BOMB or INTERNAL COMBUSTION MOTOR. It's the containment of the burning that creates the dangerous situation. I'm as guilty as everyone else about using gasoline as a cleaner and should also know better. The Airforce has an application whereby they spray a vapor from an aircraft and follow with another vapor. When ignited it creates a giant explosion and kills by taking away all available oxygen let alone the shockwave. This covers an area measured in multiple acres! When I was an Air Conditioning contractor I experienced this often with propane fired package AV/heating units. A backfire would tear off the screwed on panels and let fly 20/30 feet. I have "bad" lungs. If I'd heeded more of the safety precautions I knew they might not be now! Just play it safe!!!!!
 
Hi Daniel,
Gas fumes explode at around 13:1 ratio. In a partly filled tank it's easy to get this mixture/vapor ratio. Boom. Gas fumes can travel 20-30 feet from the source and "fire" back to the tank. Hot water heaters are great for this as they are often in the garage. I've actually seen small leaks welded on the car with a totally full tank of gas. If it's an open bucket you get a big "woosh" and fireball. IF ENCLOSED WITH A SMALL OUTLET you have a combustion chamber or BOMB or INTERNAL COMBUSTION MOTOR. It's the containment of the burning that creates the dangerous situation. I'm as guilty as everyone else about using gasoline as a cleaner and should also know better. The Airforce has an application whereby they spray a vapor from an aircraft and follow with another vapor. When ignited it creates a giant explosion and kills by taking away all available oxygen let alone the shockwave. This covers an area measured in multiple acres! When I was an Air Conditioning contractor I experienced this often with propane fired package AV/heating units. A backfire would tear off the screwed on panels and let fly 20/30 feet. I have "bad" lungs. If I'd heeded more of the safety precautions I knew they might not be now! Just play it safe!!!!!

Well, these are pretty convincing arguments. I have been doing this outside, so no combustion sources. Having said that, I think I will stop using gas after this drain. Better safe than sorry. Thanks Frank
 
Tank clean out continues. I have cleaned it out twice with the oxi-clean, and a bunch of crud came out. I have loaded it up again and and shaking and stirring every few hours for a few days. We will see how much gunk comes out then. I have noticed that the amount out last time seems less, and the chunks are smaller. Progress!
 
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Sorry for the late tip but I took my old gas tank to a radiator shop and they cleaned it and tested it. It was pretty reasonable.

I did look into that, but since I had to patch some rust holes on the top, they would not touch it. That would have been the ideal solution.
 
Still getting junk out of the tank! I am going to go get the one at the junkyard tomorrow...if it is not all eaten up, then I am going to throw in the towel and get it cleaned.
 
Hope it works out for you. If that doesn't work would a small fuel cell fit in the space? Sorry not familiar with 850s
 
After a battle royale, the junkyard 850 gave up it’s tank. It is rusted out in the back and it was full of wasps!
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Yikes! Thank goodness they were a little groggy.
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It is rusty, but not nearly as goopy inside as my old tank, so I am going to proceed with it. After I finish drowning and chasing off the wasps, I am going to cut out the rusty are for an inspection. Then, I am going to learn a new skill and braze on a patch, followed by a good tank cleaning with some sort of rust removal.
 
Cut out the rusted area today and took a look (after dealing with the last wasp). The first picture doesn’t show it too well due to the suds, but everything is covered in rust, and I found some pinholes. Off to get brazing rods, map gas and muratic acid!
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Wow! I poured in the acid, stirred it around a bit and let it sit for 5 minutes on the back. Look how clean it is! I am sold. Try to get out as much as possible before I seal it back up for some shake and bake!

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Hey, brazing is kinda fun! All the pinholes on the bottom of the tank appear to be sealed. And once I heal up from the 2nd degree burn I inflicted upon myself, I will proceed to patch the big hole. And remember...you have come to the wrong place if you expect repairs to be pretty!

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Let’s play hooky from work and try to get this patched before the weather gets gross again. First cut out a patch panel.

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And then let’s start brazing! Almost got it done before the rain started! I am still learning about the amount of heat needed and the like, but it will be sealed! Maybe get this wrapped up once the rain stops, and then get some acid in it.

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After the clean out I would respectfully suggest applying a tank sealant kit to keep from having the issues of the crud you had on the last tank. Glad there is enough there to braze to.
 
After the clean out I would respectfully suggest applying a tank sealant kit to keep from having the issues of the crud you had on the last tank. Glad there is enough there to braze to.
Agreed! Even though this tank was crud free in comparison, I will seal it just in case I missed any pinholes.
 
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