re-visiting that fuel tank issue

[Sunroof]

I located several photographs of the 1973.5T fuel tank that were posted awhile back and they show the tank split open and the one (metal baffle) and plastic swirl pot exposed. This swirl pot was coated with "Redkote" when the tank was cleaned and coated. Its the redkote that is flaking off and clogging the mesh filter that screws in from under the tank within the pot..

Its the issue of whether or not acetone will impact this piece when attempting to get the redkote off. It looks like bakelite but very thin. I was considering talking to the factory to identify the material of this swirl pot.

I believe that if the filter was removed acetone can be poured into this swirl pot several time to allow for removal of the redkote. Its worth the try and savings over a new tank.

If anyone can provide any other methods to remove that tenacious redkote from the pot via the filter inlet, please chime in. For me no idea would be far fetched.

Thanks
Bob

1973.5T

[ossiblue]

I suspect the swirl pot would be impervious to acetone, but it would be better to get official confirmation. Do you know that Redkote will dissolve in the presence of acetone? If it will, then it might be possible to clean up the swirl pot a bit following your idea. Here's my take on it:

It would probably be more effective if you could circulate the acetone through the swirl pot to enhance the dissolving/cleaning process. My thought would be to remove the filter screen and reinstall the plug. Then, using some kind of pump, circulate acetone into the pot via the return tube and capture it from the outlet tube for another cycle. Periodically, you can clean out the returning acetone and proceed until it circulates and returns clear. The trick, of course, is to be able to have enough power in the pump to fill the pot with acetone yet not allow it to overflow through the hole in the top of the pot. Perhaps shifting the tank into different positions as you circulate the solvent will allow full coverage of the inside of the pot.

An alternate method might be to simply make sure the tank is level on the ground, remove the filter and replace the plug. Then, plug the end of the outlet tube and use the return tube to fill the pot with acetone. Remove the fuel gauge sender and peer into the tank and watch the top of the pot and stop adding acetone when you see it appear at the opening. Let the acetone set and dissolve the coating. Drain and repeat if necessary. The key to this is to be able to see the top of the pot from the hole for the fuel sender--don't know if that's possible. (edit: I forgot about the baffle. I don't think you can see the pot from the fuel sender hole.)

You could still fill the pot and avoid overflowing if you measure how high above the bottom of the tank the lid is by using a dowel and sticking it up through the filter hole until it touches the top of the pot. Mark it and measure it. Then, with the tank firmly on the ground and level, measure up the side of the tank and make a mark there. Now, when you fill the pot through the outlet tube, use a piece of clear tubing, hold it straight up against the side of the tank where you made your mark. Fill the pot through the tube as it's held vertically and when the acetone begins to fill the tube instead of emptying into the pot, stop when it hits your mark.

Anyway, just a couple of suggestions that, in theory, might clean up the mess, assuming acetone will dissolve the coating.

[SCadaddle]

I sent the link to your "unique repair in Atlanta" thread to my friend Bill here in Mississippi yesterday afternoon. Here is his reply. If you want to talk to him PM me your contact info and I'll pass his along.



"Dave, Phone service was down for a while today. I went to the pelican site. His problem is the plastic swirl tank is flaking the RedKote off. That's why I make one out of steel and weld it in when I do a CIS tank. Plus never never take it to a radiator shop... you can never get all the water out and that also causes the RedKote to let go. BTW who's that masks man behind the hood? Private message him and tell him to call me OR you call him and give him my contact info. Thanks for thinking about me.Bill"

[Sunroof]

Thanks for the responses. The chemist at the company that makes redlkote is on this as well as she received the photos and they are trying to figure out what that swirl pot is made of. Like I mentioned before I might ask the Porsche factory what these pots are made of so we can find the proper solvent that would work.

I noticed in the photo that the swirl pot has a top on it. I am not sure if it was cut off or attached by those metal connectors you can see on the top. That brings up the question of high pressure water through the screw in filter port to help flush the redkote off. I would hate to "blow" the top off!

I contacted a shop in LA that does the tank opening and repair and I was surprised to learn it was $800.00 without shipping or close to a new tank. I will check out the guy in Mississippi, but I am trying my best to save $$$$ on this process asit has become personal challenge as well. This is what makes owning these old models so interesting.

Thanks
Bob

[Sunroof]

...............of course another way to access the pot is to cut a piece of the top of the tank out which would be above the pot (maybe 4 x 4) and once the pot has been cleaned weld the piece back on..........no need to split the tank in half.

[SCadaddle]

PM received and PM sent.