Question: 84 Fuel Tanks - Are they lined?

[AussieCorvetteNut]

Hi Guys,

My two-tone 84 has some issues, too many to list here, but one I found from taking the old spare tyre holder out, was surface rust on the outside of the fuel tank.

I have a parts 84 Coupe that has a DANA 36 Diff and a fuel tank, the tank looks in better shape than mine.
I removed this tank a few weeks back and it was sitting with no cover on it, in my yard for quite a few weeks.
It now has some gum leaves in the tank, but I have drained the tank and was preparing to sell it as I thought I didn't need it.

I have since taken the spare tyre holder out, as I was going to replace it with an un-broken unit I picked up in Melbourne.
When I took it off, I noticed that my original tank has surface rust on the outside of it.
I was preparing to fix my sender unit anyway as it is sticking and not sending correctly and I though when I do this, I should replace the fuel pump at the same time. I might just get a new sender unit and pump.

So, my thought is to pull the tank out, yes I removed the parts car tank, so I am familiar with the process and the amount of swearing you have to do...

I am thinking I might just replace my tank with the parts car's tank, but I was thinking before I outlay $$$ for a new sender unit and fuel pump, I should prepare the old tank...for those wondering, the build sheet was there but when I dusted it, the writing came with it.

I know one of the posts has said that the tanks are plastic lined, and I can feel this when I put my fingers in the sender unit opening, and when I look inside.
Given that I do not want to damage this lining, I was wondering what to use to prepare this tank for resto.

I have been looking at the POR15 products, although very expensive here in Australia, I can get a fuel tank resto kit for $150.00 AUD.
It contains Marine 15 to clean, Metal Prep to prep the metal and the tank liner.

Has anyone used this on a C4 tank?

I have been looking at a new stainless sender unit on eBay and a Delco fuel pump, any thoughts on these units?



Tony

 

[forrest]

Hi Guys,

My two-tone 84 has some issues, too many to list here, but one I found from taking the old spare tyre holder out, was surface rust on the outside of the fuel tank.

I have a parts 84 Coupe that has a DANA 36 Diff and a fuel tank, the tank looks in better shape than mine.
I removed this tank a few weeks back and it was sitting with no cover on it, in my yard for quite a few weeks.
It now has some gum leaves in the tank, but I have drained the tank and was preparing to sell it as I thought I didn't need it.

I have since taken the spare tyre holder out, as I was going to replace it with an un-broken unit I picked up in Melbourne.
When I took it off, I noticed that my original tank has surface rust on the outside of it.
I was preparing to fix my sender unit anyway as it is sticking and not sending correctly and I though when I do this, I should replace the fuel pump at the same time. I might just get a new sender unit and pump.

So, my thought is to pull the tank out, yes I removed the parts car tank, so I am familiar with the process and the amount of swearing you have to do...

I am thinking I might just replace my tank with the parts car's tank, but I was thinking before I outlay $$$ for a new sender unit and fuel pump, I should prepare the old tank...for those wondering, the build sheet was there but when I dusted it, the writing came with it.

I know one of the posts has said that the tanks are plastic lined, and I can feel this when I put my fingers in the sender unit opening, and when I look inside.
Given that I do not want to damage this lining, I was wondering what to use to prepare this tank for resto.

I have been looking at the POR15 products, although very expensive here in Australia, I can get a fuel tank resto kit for $150.00 AUD.
It contains Marine 15 to clean, Metal Prep to prep the metal and the tank liner.

Has anyone used this on a C4 tank?

I have been looking at a new stainless sender unit on eBay and a Delco fuel pump, any thoughts on these units?



Tony

from what I remember of the tank liners there pretty thick and downright indestructible, so if your referring what needs to be done to clean up the good tank with Gum Leaves. As long it's in good shape inside and out, I would wipe it out good and clean and use a fuel system friendly solvent (sea foam/Lucas fuel treatments) to wipe down the insides, and without a doubt new fuel pump and strainer& pulsater if equipped. sending unit is a judgment call but recommended.

 

[AussieCorvetteNut]

from what I remember of the tank liners there pretty thick and downright indestructible, so if your referring what needs to be done to clean up the good tank with Gum Leaves. As long it's in good shape inside and out, I would wipe it out good and clean and use a fuel system friendly solvent (sea foam/Lucas fuel treatments) to wipe down the insides, and without a doubt new fuel pump and strainer& pulsater if equipped. sending unit is a judgment call but recommended.

Hi Forrest,

Yeah I was wondering how robust the internal lining on the tanks were, I didn't want to go through a process and get to the sealing stage if the lining is bullet proof anyway.
I can feel the lining inside the top of the tank.

The POR 15 treatment is cleaner, metal prep and sealer, but I would expect that process on tanks for older cars.

I might pull the tank outside and take another look.

Thanks for your help.



Tony

 

[forrest]

Hi Forrest,

Yeah I was wondering how robust the internal lining on the tanks were, I didn't want to go through a process and get to the sealing stage if the lining is bullet proof anyway.
I can feel the lining inside the top of the tank.

The POR 15 treatment is cleaner, metal prep and sealer, but I would expect that process on tanks for older cars.

I might pull the tank outside and take another look.

Thanks for your help.



Tony

Cool Tony you have already done what I had an after thought on, you already felt around inside the tank. make sure the tank feels consistent inside to the out side I have seen some way back when were the inner liner shrunk. so be aware that it can occur. but not likely. when it dose occur it usually buckles in the middle and can pull way from sending unit hole

 

[Hot Rod Roy]

Does your gasoline contain ethanol? Some aftermarket fuel tank coatings won't hold up for the long term continual contact with ethanol fuels.

 

[AussieCorvetteNut]

Good Point

Does your gasoline contain ethanol? Some aftermarket fuel tank coatings won't hold up for the long term continual contact with ethanol fuels.

Hi Roy,

Good point...


Our gas that contains ethanol are marked E10.
I run Shell or BP 98 RON and as far as I know, these are ethanol free.
I am pretty sure they have to be marked as so in Australia or there will be legal pain ad.

Good point though, I might do a bit more investigation into ethanol affecting the lining, especially if I need to use the POR 15 product.



Tony

 

[AussieCorvetteNut]

....I know one of the posts has said that the tanks are plastic lined, and I can feel this when I put my fingers in the sender unit opening, and when I look inside.
Given that I do not want to damage this lining, I was wondering what to use to prepare this tank for resto.

I have been looking at the POR15 products, although very expensive here in Australia, I can get a fuel tank resto kit for $150.00 AUD.
It contains Marine 15 to clean, Metal Prep to prep the metal and the tank liner.

Has anyone used this on a C4 tank?

I have been looking at a new stainless sender unit on eBay and a Delco fuel pump, any thoughts on these units?



Tony

Update:

I took the tank outside and threw a torch light in to inspect, put my arm as far as I could and only felt a residue on the bottom of the tank.
Only 4 gum leaves and no damage from them... Australian Gum Leaves leave a stain like concentrated tea leaves do in the bottom of a cup...those poor bloody Koalas, no wonder they just sit around :L
I think it only needs a clean out with a fuel type cleaner. The residue looks like it is old fuel and a bit like shellac from woodwork class.
I didn't seem to have any rust, well only around the top gasket area, which I can wire brush off.

The bottom lining did seem intact but I think it may also be porous due to age.

Not sure if I should shell out the $150.00 AUD for the POR 15 Fuel Tank Restoration Kit or not, don't want to get 5 or 10 years down the track and have to pull out the tank again.


What do you guys reckon?



Tony

 

[forrest]

Hi Roy,

Good point...


Our gas that contains ethanol are marked E10.
I run Shell or BP 98 RON and as far as I know, these are ethanol free.
I am pretty sure they have to be marked as so in Australia or there will be legal pain ad.

Good point though, I might do a bit more investigation into ethanol affecting the lining, especially if I need to use the POR 15 product.



Tony

I don't know that's one of those judgment calls its in front of you with your eyes on it. but from what I remember of those lining's I cant imagine it going porous. but 30 years of gas on two continent's could wear on the best of things. also when the tank was built & designed I think the term E85 or special blend gas was yet born. so a more modern protective layer might not be to far off base. my only concern with the coatings is adhesion we all know coating are a cover up and always seem to want to flake off, I would hate to have some poly paint flaking in my tank