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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22438
Location: Kimball, Mi
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 Posted: Mon Feb 27, 2023 9:38 am Post subject: Re: 1970 Auto Fastback with FI |
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The fuel tank still looks kind of nasty. You might want to try muritic acid (swimming pool cleaner), as that might take some more of the rust off, and is recommended in the thick Blue Bentley for the early cars. VW also recommends using soluble oil (industrial cutting fluid) to coat the tank after rinsing to keep it from rusting again. I'd also ask Ray Greenwood (our forum chemist) what he'd suggest as far as using chemicals to clean the tank and to keep it from rusting, as he's worked with more chemicals in his life than I have.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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secretsubmariner
Champagne Wrangler
Joined: January 08, 2011
Posts: 3104
Location: Tulsa, OK
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| Posted: Wed Mar 01, 2023 2:40 pm Post subject: Re: 1970 Auto Fastback with FI |
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| raygreenwood wrote: |
The steering damper you showed a few days ago that is not correct....is actually for a type 4 vehicle....and is fairly rare.
Ray |
Hey Ray lol yes I posted that it was the wrong one a while back. The correct one is in the car now. I ripped the box a tiiiiiny bit and I'm not wanting to risk a restocking fee with rockauto only for them to refuse the part. So I am likely going to list it on ebay later.
And Bob, I do plan on doing more to the inside of the tank, although I am not wanting to use acid right now. I'm more of a mushroom guy  just kidding psychedelics give me the hard poops. I don't care for them lol
| secretsubmariner wrote: |
| I will probably do an acetone rinse followed by a 12 hour vinegar soak and a few more rounds of vinegar+bolt agitation before installing it. |
I'm thinking I'll do a loooong vinegar bath and a few more rounds of sloshing the nuts and bolts around. You're right, there is more crud that could be removed, but damn, I wish you could've seen the original state it was in. Disgusting! The thing is, I'm stacking harmful chemicals right now in my garage and my situation isn't exactly ideal for it. I need to figure out where I can dispose of some stuff safely before I pile on too many more.
_________________
-Tony
ᏣᎳᎩᎯ ᎠᏰᎵ
1978 Champagne Edition Bus FI
1970 Auto Fastback FI |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Thu Mar 02, 2023 10:48 am Post subject: Re: 1970 Auto Fastback with FI |
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| secretsubmariner wrote: |
| raygreenwood wrote: |
The steering damper you showed a few days ago that is not correct....is actually for a type 4 vehicle....and is fairly rare.
Ray |
Hey Ray lol yes I posted that it was the wrong one a while back. The correct one is in the car now. I ripped the box a tiiiiiny bit and I'm not wanting to risk a restocking fee with rockauto only for them to refuse the part. So I am likely going to list it on ebay later.
And Bob, I do plan on doing more to the inside of the tank, although I am not wanting to use acid right now. I'm more of a mushroom guy just kidding psychedelics give me the hard poops. I don't care for them lol
| secretsubmariner wrote: |
| I will probably do an acetone rinse followed by a 12 hour vinegar soak and a few more rounds of vinegar+bolt agitation before installing it. |
I'm thinking I'll do a loooong vinegar bath and a few more rounds of sloshing the nuts and bolts around. You're right, there is more crud that could be removed, but damn, I wish you could've seen the original state it was in. Disgusting! The thing is, I'm stacking harmful chemicals right now in my garage and my situation isn't exactly ideal for it. I need to figure out where I can dispose of some stuff safely before I pile on too many more. |
I have become much more conservative with suggesting Muriatic acid use for gas tanks.....in the forums ONLY.
It is the best/correct chemical for serious de-rusting....but I have to temper this with the fact that I work with chemicals for a living and I have experience in hazardous waste disposal.
Its really not that big of a deal but it can be if a person makes a couple of simple mistakes.
These are must haves:
big plastic tub for neutralizing the acid when done
About 8 pounds of baking soda.
Cross ventilation (outdoors)
An acid/VOC respirator (you should have this anyway)
Good gloves
Splash goggles.
A running garden hose.
I would not use vinegar. It works but is just not that good and on long soaks it can be around too long and if its vapors get to electronics or important parts...it causes just as much damage as any other acid.
I would first get rid of all the thick crusty rust inside the tank. A combination of sand and small sharp gravel. Spend some time shaking it around hard.
Then I would get one of the phosphoric acid products like Ospho.
See...phosphoric acid is a strong acid....but is not an "oxidizing" acid like muriatic acid. You still need the same basic precautions but it is not as hard to neutralize. There are some other "acids" that are really in the same family (Gluconic acid, lactic acid etc.) that are much safer, a little slower but eat rust.
The key component of phosphoric acid based products is that once you use them full strength....when they dissolve rust down to bare metal....you can then rinse them out....then let the metal part sit for a day or so to form very thin surface flash rust.
Then, dilute the phosphoric acid product (read the directions)...and slosh some around fully inside the tank and then let it dry for 24 hours without rinsing.
During that time, the phosphoric acid converts that very thin "flash" rust to iron phosphate. That iron phosphate coating along with just keeping fuel in your tank...means that the tank will likely never rust again in your lifetime.
Evap-o-rust is a really good product. Its PH neutral. It is a "chelating" product that strips rust electrochemically. At $30 a gallon at harbor freight it may be your safest and simplest bet.
Another good one is "krud cutter" (sodium silicate based- high PH). Its about $30 a gallon at Home Depot.
Even CLR is pretty good.
Here is a shoot out on project farm among rust removers.
Make note of the black color coating that Naval Jelly gave the nuts. This is the phosphoric acid at work.
https://www.youtube.com/watch?v=6-MC_ZEXQbw
By the way...BIG WARNING...DO NOT use Muriatic acid on bolts and nuts. It damages the hardness of the bolts (hydrogen embrittlement)....especially bolts above grade 5/class 8.8. The harder the metal the more damage it will do for strength.
The guy in these videos is excellent but the muriatic acid is not really eating metal. The surface is getting rough because it removed rust all the way down to the molecular level. It is the rust that removed the metal. When the acid fully removes the rust....you see roughness. The acid also removes the original plating the bolt had...taking it down to the grit blasted, pre-etched surface the bolt had before plating.
Ray |
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notchboy
Samba Member
Joined: April 27, 2002
Posts: 22464
Location: Escondido CA
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| Posted: Thu Mar 02, 2023 11:26 am Post subject: Re: 1970 Auto Fastback with FI |
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My go to has been Evaporust in a jar in a bath of hot water in my ultrasound tank. Ran at 2 to 3 30 min cycles.
Not for a tank resto, just the odds and ends shade tree tinkering shit on the bench  
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| t3kg wrote: |
OK, this thread is over. You win. |
Jason "notchboy" Weigel
1964 1500 S
1964 T34 S Convertible
1977 Westfalia Camper pop-top |
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W1K1
Samba Member
Joined: March 04, 2004
Posts: 4923
Location: Southern AB
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| Posted: Thu Mar 02, 2023 12:56 pm Post subject: Re: 1970 Auto Fastback with FI |
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our local radiator shop will do the muriatic acid, and Redcoat tank sealer, it cost $180CDN ( which is like $10 US ) to have it like new so I opted for that, instead of trying to do it myself. He does a pile of them for the hotrod guys in Alberta.
I still like the muriatic acid for stripping engine tin, 2 days in the tub will usually strip everything off the engine tins.
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1973 super
1965 squareback 1500E
1971 bay window westy- subi swap |
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secretsubmariner
Champagne Wrangler
Joined: January 08, 2011
Posts: 3104
Location: Tulsa, OK
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| Posted: Thu Mar 02, 2023 2:18 pm Post subject: Re: 1970 Auto Fastback with FI |
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| raygreenwood wrote: |
...
These are must haves:
big plastic tub for neutralizing the acid when done
About 8 pounds of baking soda.
Cross ventilation (outdoors)
An acid/VOC respirator (you should have this anyway)
Good gloves
Splash goggles.
A running garden hose.
...
Ray |
Wow, dude you are such a serious wealth of information. Invaluable must be your middle name. THANK YOU, seriously, for such a detailed comparison between the options for rust conversion. I am reconsidering my plan with your new knowledge in mind.
| notchboy wrote: |
My go to has been Evaporust in a jar in a bath of hot water in my ultrasound tank. Ran at 2 to 3 30 min cycles.
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I've actually been eyeing an ultrasonic cleaner online for a while now. I want to do exactly that with some of the dirty nasty fasteners and bits. Thanks for the info!
| W1K1 wrote: |
| our local radiator shop will do the muriatic acid, and Redcoat tank sealer, it cost $180CDN ( which is like $10 US Laughing ) |
It didn't even occur to me to ask the shop if they do any other stages of the gas tank refurbishing process. That's awesome though, nice tank!
_________________
-Tony
ᏣᎳᎩᎯ ᎠᏰᎵ
1978 Champagne Edition Bus FI
1970 Auto Fastback FI |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Thu Mar 02, 2023 3:03 pm Post subject: Re: 1970 Auto Fastback with FI |
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Seriously.....I would skip the "Red coat" or any other form of tank liner.
Out of all of the liquid liners...Redcoat is one of the better ones. It's a urethane based liner with chopped glass or polymer fibers added. Because it's purely solvent based it will not have risk of curing issues like POR-15.
The POR-15 is a catalyzed epoxy based coating. It can have failure issues from product shelf life, poor mixing, humidity during mixing and use or from solvent/oil contamination. Thats just curing. When it works perfectly.....curing wise....then we can get into questions of adhesion.
The Redcoat will not have curing issues but can just as easily have adhesion issues.
The last thing you want is any tank liner to have adhesion issues. It will be 10X harder to get the liner all out to do it again.
In reality.....if you simply COMPLETELY derust the tank....then let it grow a patina of flash rust inside....that is a seed layer for a phosphoric acid product to convert the flash rust to iron phosphate which is an oxide. That oxide will never rust....but it's thin. It's only where the rust WAS.
From that point on....as long as you keep the tank 1/3 full or better for periods when it's sitting around....there is not enough oxygen to start rust. It will never rust.
The obje t of removing ALL rust first is because thin liquids like Ospho/phosphoric acid...cannot penetrate more than about 0.003" of crusty rust.
So you get rid of the crusty rust....and then just let it flash rust to grow a thin lCOMPLETE layer of about 0.0005 to 0.001" thick to convert.it.
The only time I would use a fuel tank liner is if it's a tank you just cannot replace....that has very fine constellations of pinholes around the seams and its to thin to solder. A product like Redcoat would be excellent for that. Ray |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22438
Location: Kimball, Mi
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| Posted: Thu Mar 02, 2023 3:05 pm Post subject: Re: 1970 Auto Fastback with FI |
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| secretsubmariner wrote: |
| raygreenwood wrote: |
...
These are must haves:
big plastic tub for neutralizing the acid when done
About 8 pounds of baking soda.
Cross ventilation (outdoors)
An acid/VOC respirator (you should have this anyway)
Good gloves
Splash goggles.
A running garden hose.
...
Ray |
Wow, dude you are such a serious wealth of information. Invaluable must be your middle name. THANK YOU, seriously, for such a detailed comparison between the options for rust conversion. I am reconsidering my plan with your new knowledge in mind.
| notchboy wrote: |
My go to has been Evaporust in a jar in a bath of hot water in my ultrasound tank. Ran at 2 to 3 30 min cycles.
|
I've actually been eyeing an ultrasonic cleaner online for a while now. I want to do exactly that with some of the dirty nasty fasteners and bits. Thanks for the info!
| W1K1 wrote: |
| our local radiator shop will do the muriatic acid, and Redcoat tank sealer, it cost $180CDN ( which is like $10 US Laughing ) |
It didn't even occur to me to ask the shop if they do any other stages of the gas tank refurbishing process. That's awesome though, nice tank! |
Russ Wolfe when he was alive and on here recommended NOT coating the inside of the fuel tank with those tank sealer kits. This is mostly because some of today's fuels will eat that layer off the tank causing other problems. I've seen it happen to a friend, who got rear ended because of that crap clogging up the fuel line. Russ' big issue with tank sealer kits was they would clog the drain holes around the FI return cup in the tank. That cup keeps fuel around the tank drain to keep the pump full of fuel in turns.
Speaking of fuel line, have you cleaned yours out yet? I tried roto rootering my 64 T-34 fuel line, only to find a clog in it. I ended up using some liquid carb cleaner (Berryman's) with a hose and small funnel to build a "head" so that once the clog cleared, I was able to flush the line out. It took overnight just soaking the carb cleaner thru it, for it to actually pass thru. Then I used a throttle cable to pass thru end to end, followed by flushing it several times until it came out clear. Just something to keep in mind while you have the tank out.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34023
Location: Conejo Valley, CA
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secretsubmariner
Champagne Wrangler
Joined: January 08, 2011
Posts: 3104
Location: Tulsa, OK
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| Posted: Fri Apr 21, 2023 10:00 am Post subject: Re: 1970 Auto Fastback with FI |
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Thanks for the replies everyone!
1. Yes, I will absolutely AVOID all tank sealers. I already refurbished the fuel tank in my bus, and after finding 11 pounds (hyperbole) of crusty ol' tarred-out expired liner in it from a PO - I learned then and there its a bad idea.
2. I will definitely "roto-rooter" out the fuel lines in the tunnel before putting the tank back in - great idea! Although the goopy tank stuff wasn't in the lines past the old fuel pump, there's still a chance there's build up or a clog. Thanks for the suggestion!
NOW! I took a little time off from the car to get the garden ready for spring and fix up some stuff on my house. I'm back at it!
I have two things I'm thinking about before putting the tank back in.
The first, is the master cylinder. It looks OK, but the rubber grommets on top are kind of loose? I'm not sure how loose they should be. Fortunately, the MC and booster in the bus function perfectly and just needed a bleed and new fluid to work great again....but that means that I'm not personally well-versed in what to look for here. The grommets are a little cracked, but not really all that dry, if that's possible.
Now, I've scoured several master cylinder threads in this forum and I haven't really found what I'm looking for. There's many threads on what MC is swappable from late or early, or how do I rebuild this MC with this or that kit, etc.
Can you look at these pics and tell me if I need to replace these grommets? Or are they OK? Do I NEED to just buy a German MC to directly replace?
This is a pic of the grommet with me lifting up on the hose a little bit
And this is a pic of the grommet with me pushing down on the hose a lil bit
Here's a top view in case it's handy:
My second thing, since this is easy access for now, has to do with the steering box. I would guess it has coated the beam in gear oil. The fore section of the beam is darker than the aft section. I know I need to clean up the little ground wire and its connectors. But should I attempt to refill it? Is there a quick way to check the fluid?
The pittman arm also has a little bit of a clunk to it, which I thought was a tie rod end.
Here's an overview of the beam area, for funsies. Anything else look amiss?
the DS tie rod is not bolted in yet, I need to push the car out of the garage to access it and I didn't have time last night.
After this, I'm going to unhook the gas lines in the back so I can roto-rooter before buttoning up the front end. I even got a nice new bonnet seal
Thanks again everyone! Sorry I've been lurking so long without an update lol.
_________________
-Tony
ᏣᎳᎩᎯ ᎠᏰᎵ
1978 Champagne Edition Bus FI
1970 Auto Fastback FI |
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DariuszPlich
Samba Member
Joined: July 06, 2017
Posts: 60
Location: Polska
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| Posted: Tue Jan 23, 2024 12:28 pm Post subject: Re: 1970 Auto Fastback with FI |
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| Very nice Fastback. I see you have similar repairs as me. Good luck and I look forward to updates |
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Mike Fisher
Samba Member
Joined: January 30, 2006
Posts: 17974
Location: Eugene, OR
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| Posted: Tue Jan 23, 2024 12:59 pm Post subject: Re: 1970 Auto Fastback with FI |
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They make a blue smooth plastic hose for brake hoses.
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69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold
Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey |
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