1969 deville fuel tank problem...

[1969cadillac]

hello out there ! I have rust in my fuel tank - please see pics attached . the tank was cleaned and repaired some years ago and has been sitting..

Q. will the rust cause a problem as it looks like it is NOT flaking off …

Q. is there something I cause use to dissolve it if it likely to cause a problem ?

I have heard of the POR15 fuel tank sealing treatment but as I am selling the car I don't want to spend the money

your thoughts would be appreciated , Murray Mules

[TJ Hopland]

Was there a reason you were checking in the tank in the first place?   Was it sitting empty?  If it wasn't empty was the fuel that came out rusty looking?  Have you already 'made the deal' for the sale?

DIY tank sealing seems to be a hit and miss, mostly miss on this sort of scale.   People do seem to have decent success with small engines and motorcycles so maybe its just the increased working time that makes it more difficult.  A bad sealing job seems to make things much worse than a little rust. 

Is the tank out or is there some sort of inspection hole you are using to see inside?   If its out you could try and clean it a bit.  A and improvement on an old trick I heard about recently is to use a couple pounds worth of random nuts and bolts.  Just like the gravel trick the sharp edges should chip away at the rust.  Reason I think hardware is an improvement over gravel is you can use a magnet to get ALL the hardware out.  With the gravel in some tanks it can be a real pain to get it out. 

[Big Fins]

Take the tank to a radiator shop and have it boiled out.

What really bothers me is the fact that he states he wants to sell the car, but not put any money in it. I can understand this to a degree.

My question is, and I don't want it to be taken out of context is, what else was done on the cheap that should have been done right? Brakes, steering components, other safety items?

Many people read this board, not just CLC members. You are severely hurting your potential sales audience with a post like that. Not every buyer has the ability to observe and inspect mechanically, a desired car. They sometimes have to rely on the honesty of the seller.

[The Tassie Devil(le)]

I have cleaned out a fuel tank with gravel, and then removed the gravel with a vacuum cleaner.

To rotate the tank, I tied it to the open end of a cement mixer, and set it in different positions to allow the stones to do the work.

Bruce.

PS.   Ever seen a rusty bowl on a mixer after it has been used?

[chrisntam]

Get one of these, do it right, add $500 to the price of the car and explain what you did and the cost.

https://www.ebay.com/itm/Fuel-tank-for-Cadillac-1969-1970-w-o-eec/232514043489?hash=item3622eabe61:g:1nUAAOSwK89Z14bV

I had the tank on my '75 olds cleaned out by a radiator shop, shortly after I put it back in, my fuel filter clogged to the point I couldn't drive it - it was clogged with rust.  I put a new tank in shortly thereafter...

[The Tassie Devil(le)]

Not bad with shipping to Australia of US$146.00, which equates to AU$214.00, bringing a total of AU$724.00

Bruce.

[Scot Minesinger]

The metal gas lines from tank to fuel pump and from fuel pump to carb. are probably rusted inside too and should be replaced.  On my 1970 SDV with low mileage, the tank was super clean, but the metal fuel lines were not.  In the interest of long term reliability I routinely replace the metal fuel lines and when I did rust poured out of them.

[Kevin Bielinski #13320]

Get one of these, do it right, add $500 to the price of the car and explain what you did and the cost.

https://www.ebay.com/itm/Fuel-tank-for-Cadillac-1969-1970-w-o-eec/232514043489?hash=item3622eabe61:g:1nUAAOSwK89Z14bV

I had the tank on my '75 olds cleaned out by a radiator shop, shortly after I put it back in, my fuel filter clogged to the point I couldn't drive it - it was clogged with rust.  I put a new tank in shortly thereafter...

Agreed!

[Scot Minesinger]

Unfortunately, mechanical improvements pay few dividends in resale value.  I often joke about how a complete suspension and steering restore, including tires and shocks (ball joints bushings front and rear) which could easily cost 4k to 6k, will add 15 cents to the value of a classic Cadillac.  Some things like working ac usually is worth doing.  This supports that old adage that the least costly classic is the best you can afford.  Generally, and especially a fuel system delivery improvement will not add any value to the car being sold, because all the value is perceived to be in the cosmetics and fuel systems are taken for granted.