SC Fuel Tank Cleaning Revisited
 

After reading the replies to my previous post on this subject I went back to the recommended radiator shop with some images of the inside of an SC tank and swirl pot (that had been posted on rennlist by a guy who had cut open a tank). I showed them the images and he assured me there would be no problem with his solution destroying the pot. He said the main key to success was to blow air through both inlets, particularly while recoating the inside of the tank. He also said that something similar exists in practically all cars that have their fuel pumps in the tank, and that of course includes about everything with injecton.

So I think I'll let him have a shot at it. If I have to I will have to replace the tank down the road. I have lots of other things to deal with before I need a fuel tank, believe me.

A question is how does one know if the swirl pot is doing it's job or not? ALSO, I wonder how the swirlpots made of thiry-year old plastics are coexisting with today's ethanol fuels (which I try to avoid anyway but it's not always possible)?

i wonder the same thing about todays cars .. just about all intakes runners for example are plastic these days .. you gotta figure some thought went into this given the constantly increasing pecentage of ethanol in fuels... maybe not tho .. time will tell..

Yes, and a lot of radiators are either all plastic or have a lot of plastic components, and these guys have to stay in business somehow. Not to mention the fact that the EPA/OSHA might have a hand in getting rid of some of the more noxious chemicals they used to use. I'm going to go ahead and give it a shot; if it ruins the tank I'm only out $110 for trying. And the tank is certainly useless as it is.

Now that it's dried out inside I can shoot a flashlight in the sender hole and indeed see the top of the swirl pot.

I promised I would follow up on this so here goes.

I took the tank to be dipped. It cleaned up wonderfully, and most importantly the plastic "swirl pot" inside came through with flying colors! No worries there. It's all orange and new looking along with the inside of the tank. Absolutely no visible damage.

The outside of the tank also still has it's coating, although it's no longer a pristine gray color and looks more like something that spent time on the bottom with the Titanic. So some cosmetic work would be necessary there.

Note the word "would" above; here's the "but" of the story. Some important items did not come through the process unscathed. They are the screw/flared fitting for the return line and the small studs that retain the fuel level sender. These items were almost totally eaten up/destroyed by the chemical dip! The guy at the shop said he had had similar experiences before with VW tanks so whatever the material issue is it must be a German thing.

As these would be about as difficult to repair as the swirl pot had it melted, I'm thinking the tank is scrap; clean but still scrap. I have no idea where to source that flare fitting, and then there's the issue of making sure it seals up properly with the line to the swirl pot if I had it.

Ideas are welcome, including perhaps sources for good used tanks.

Saw this on speed last weekend.

http://twoguysgarage.com/?p=5418

Here's my last word on this; next stop a repro or used tank.

The attached images show the result of the tank cleaning. The inside of the tank, the swirl pot, and to a certain extent the coating on the outside of the tank came out fine. (Well, the coating was certainly damaged, but not removed) However the steel (?) studs that retain the fuel gauge sender and the fuel return line inlet fitting were totally destroyed. But it wasn't usable as it was before dipping, so not a lot was lost that wouldn't have been anyway.