MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - New Gas Tank

I'm about to replace my gas tank as there is a bit of rust in the gas. The bottom of the tank looks fine but it must have rusted on top. I assume the replacement tanks are painted on the outside but bare steel inside? ... I don't want to repeat the problem, so I was wondering if that "slushing" solution they sell at Moss -- to coat the inside of the tank -- is worth the cost. Anybody tried this stuff? (Also, just to have this replacement serve as The Final Solution, I was going to get the outside powder-coated to avoid all possible rust. Reasonable idea?)
Bill

Way back in 87 or 88 I had the gas tanked lined on my B. I understand they sloshed a solution around inside so it coated the tank. I have no idea how old the tank was at the time but there was no visible rust. At any rate here it is 2002 and the tank is still in great shape. Every time it is off, for one reason or another I wash it out to get any sludge etc out and repaint the outside.

Bruce

Bruce

Bill-
New fuel tanks have a protective coating inside of them. If they didn't, they'd have a coating of rust on the inside when they're delivered. The "slushing" compounds have one great disadvantage. Inside the tank there's a screen to help keep debris out of the fuel line. The slushing compound can plug it up and interfere with fuel flow. If your going to coat the interior of the tank in the interests of long-term protection (a good idea, actually), remove that screen and install a fuel filter between the fuel tank and the fuel pump.

Here's something you need to know: Not all MGB fuel tanks on the market today are equal. There's been some low-price, bargain-basement MGB fuel tanks that have no internal baffles to prevent the fuel from sloshing around inside. If the tank is low on fuel, you may not get any gas while going up a steep hill as it will simply go to the rear of the tank, leaving the fuel pickup high and dry.
Steve S.

Steve,

The one I bought, unfortunately, has no baffles. Oh well. But it's 12 gallons rather than the old one's 10, so my gas-swilling V8 may spend a tad less time at the station. Query: I get your message about the internal screen, but I don't see any way to remove it. Why not just blow hard through the pipe after slushing the tank, and thus blow any gunk out the screen before it dries?

(I've always run a fuel filter between the tank & the pump anyways -- no downside to doing so!)
Bill

When they lined my tank they inadvertently plugged the line which leads to the vapor recovery canister. So when the gas expanded in the tank it just expanded out the cap. When I contacted the company they were more than willing to address the problem but since we live in different towns he suggested filling the line with Acetone and once the Acetone level fell, to blow through the line and then flush the tank as Acetone will actually dissolve the lining. Hope this helps.

Bruce
Bruce

Bill,
The interior coating is an excellent idea and well worth the trouble to do.
They do work if applied correctly and the coating applied by the manufacturer is mariginal to say the least since they are making these things down to a cost remember.

Powder coating the extereior is also another excellent idea as the top of the tank is a notorious rust trap on 'B's.
The tank can rust from moisture getting into the space between the top of the tank and under the boot floor and any product offering any level of extra protection like POR 15 or powder coating is a definite worthwhile step to take in my opinion.

Cheers, Pete.
Peter Thomas

Where is the best and cheapest place to buy a tank, bearing in mind the various qualities around.

Also these slushing kits seem frightfully expensive, perhaps someone knows what the compounds are so we can go to an industrial chemical source, and get a bigger bang for our dollar, or pound in my case.
Tom

Tom,

I have just bought a new fuel tank from Moss Darlington. It was made in Canada and is galvanised. I think it cost me about 50 pounds and at such a price, for such a product, I simply could not be bothered to spend time or money on the old one.

Derrik, at Moss Darlington, is also incredibly helpful.

'Hope this helps,

Angus.
Angus Munro

MGOC also sell the galvanised tanks made in Canada for about £60. Cheapest place is probably a breakers yard, best place is wherever you can buy the highest quality; this is unlikely to be a breakers yard. Incidentally, British Motor Heritage are about to start manufacturing new US spec tanks.

Geoff

Geoff King

I had the tank cleaned and resealed by a radiator shop during restoration. I am now experiencing a intermintent fuel line blockage. The line from the pump to the carbs is clear and clean. I suspect that there is some coating material in the intake screen blocking the flow. How to I get to the screen and how do I remove it? 1968 MGB GT non vented tank.
Steve

I slushed a brand new tank on a midget some years ago. Completely blocked the gauze over the feed pipe. Could do nothing but throw the brand new tank out and get another one. Won't do that again! How long do you want your tank to last for goodness sake? I reckon my original one lasted at least 25 years - that'll do me.
Mike
Mike Howlett

My new tank slushing experience was a nightmare. I did it when the ambient temperature was much too cold, and the mix didn't work correctly; it set up much too thick and too soon. Plugged the 'sock' filter on the outlet. I took the tank to a stripping shop to have it burned out, which served to remove the plugged filter. After that, I started over, painting the tank exterior and simply coating the inside with ATF until use. Joe
Joe Ullman

I'm with Mike. My original lasted 25 years. If the car goes another 25, it's earned another new tank.

When replacing mine this year, I painted the outside with four coats of Rustoleum and two coats of carnauba wax. I think the important thing though, is that I trimmed the packing strips to match the tank ribs - so they won't trap water on top. Remember, these tanks rust from the outside in. Coating the inside won't protect from that.

Anyway, IMO the best way to keep the inside of your tank from rusting is to keep it full and drive your car a lot. You don't want a lot of air space in there to allow water vapor to condense. And you want to cycle the gas through it, so any contaminants don't sit in your tank and fester. They'll be carried away in small amounts to your filter. Driving the car also sloshes the fuel around, which coats the inside with petroleum - a marvelous rust inhibitor.

Matt Kulka

Stop messing about and get a stainless tank.....
Chris Betson

Chris, Who offers one? For future referance.
Luigi

I thought there was an issue with the stainless tanks leaking along the seams. On second thought, that's gotta be ridiculous, because every tanker truck on the highway would be leaking! You can also purchase an aluminum tank from Cambridge Motorsport -- spendy, but probably very light weight.
Ted

A comment and a question.

Check the archives. Back in November 2000 there was an extended thread "??? Can I use Rustolum Oilbased Paint for parts of my car?????". Mike Brown of Seven Shop British recommended using Rustoleum as a sealing compound. "We use it after cleaning fuel tanks as well to prevent rusting in these. We thin the primer about 50?50 with Rustoleum reducer, then use the mixture as a sloshing compound in the tank, being careful not to plug up any screens which may cover the tank pickup tube. We then force dry the inside of the tank for a couple of days in the hot sun or with a lamp attached to the outside, and the tank's ready for fuel."

Now the question, how do you determine if the replacement tank offered has the desired internal baffles? And who in the US offers a stainless tank with the baffles?

Thanks

Larry
58 A
69 C in restoration
Lawrence Hallanger

I specifically chose a new tank without the baffles for its larger capacity. With keeping the tank full and legal driving practises I decided the extended driving range was worth the odd chance of the float chamber running occasionally low.
Carl Holm

If a tank is not rusted on top what is the best (and safest) way to clean the outside of it before painting?

I need to repair some rust in the boot of my car so I will be dropping the tank first. Be nice to give it the treatment while it is off the car!

Simon
Simon Jansen

Carl

Baffles should not make any difference in the capacity of the tank. The difference in tank capacity is due to the evaporative loss system added in 1970, which reduced tank internal capacity about 2 gallons.

Larry
Lawrence Hallanger

Simon,

There is an excellent metal protecting paint called POR 15 which should be readily available there.

Tough durable and can be brush or spray painted to a good gloss finish. Good stone chip resistance too.

There is also the Hammerite range of finishes which give a different result but pleasing none the less.

Cheers, Pete.
Peter Thomas

Here's a funny twist on the new tank saga - I know it's stupid but it happened to me: after the installation, I noticed my fuel gague was operating in reverse. That's right, reading "E" on a full tank, and then trending towards "F" as fuel was used up. I believe this is a polarity problem, but it sure is quaint.

-D.
David

My tank looks OK but the mechanic who took it off put a screwdriver into it, presumably he could not be bothered to siphon it off, so it has a hole in the bottom.

Any ideas on repairing it, welding for instance.
Jack

Chaps

Interesting stuff. There are stories around that unleaded fuel reacts with slosh sealant???
After 20 yrs, my tank had gone rusty inside but only at the lowest point. (I looked inside with a torch).
The rust extended in a line across the front edge of the tank and in the recess where the fuel take off sits. This is where the water droplets sit. There was no sign of rust anywhere else, even on the inside of the top. I'm supposing that the fuel vapour stops the rot by purging the oxygen. Remember that school experiment? Nail in dry test tube - minimal rust. Nail in water in test tube - rust. Nail in boiled water in sealed test tube - no rust.
Welding a tank?? - no way without body armour. Quick story - friend has tank full of rusty shale. Concludes that solution is to vacuum out rusty shale with nozzle.
All went well until vacuum filled with fuel vapour, and electric motor ignited it. Exploding vacuum is spectacular party trick. Finally, if you have a length of door seal, it will fit well across the front edge of the tank where most of the moisture splashes up. When you tighten the tank it presses against the boot floor to make a good seal.
Dave
Dave Wellings

Jack, there are places that specialize in tank repair, even rusted out ones. Don't, Whatever else you do try, DON'T try welding your tank. A tank filled with gas is a thousand times more safe than an empty or nearly empty gas tank. The fumes are what cause the explosion. 14:1 is the perfect mixture ratio- like in your MGB combustion chamber. Only in Hollywood movies do 50 gallon tanks of gas explode in chain reactions when one is hit by a pistol bullet. The pros have safe techniques and equipment for tank repair, so leave it to them, please. Look in the yellow pages, ask around, but do not try to weld or bronze that patch. Remember that when Dave Wellings in Yorkshire looked inside his tank with a "torch" it wasn't attached to an oxy-acet unit, it was what we call a flashlight!
Ken R
Ken Rich

Oops!!
This transatlantic thing - quite right Ken, flashlight.
How did you know it wasn't the oxy torch????

Dave
Dave Wellings

Dave

Isn't it obvious? You are still here and posting on the BBS!

Larry
Lawrence Hallanger

I sloshed my tank last year after having it cleaned and hot tanked. I got a kit from a local harley davidson repair shop here in town. I guess harley's still have a problem with rusting tanks due to the fact many of them sit for months at a time and are not driven. Anyway, I used the solutions and it worked out well. takes a couple days to complete but worked fine.
andy heston

I sloshed my tank last year after having it cleaned and hot tanked. I got a kit from a local harley davidson repair shop here in town. I guess harley's still have a problem with rusting tanks due to the fact many of them sit for months at a time and are not driven. Anyway, I used the solutions and it worked out well. takes a couple days to complete but worked fine.
andy heston

Is hot tanking when you dip the tank in one of these diesel cleaning tanks, if so could I get it dipped, and then get the hole welded up.
Jack

Jack, go to those yellow pages- there is a place over here on the west coast of Canada ( and we, comparatively, are in the sticks!) called LEAKERS, which will make an old ,rusted out tank better than new, and they don't want you to meddle with the tank before they get it. There must be places like that in your area. Your problem seems to be very minor.
Ken R
Ken Rich

For holes in underside of tank I refer those listening to a sound and foolproof solution that a collegue of mine used when he owned an MGB some <ERHEM!> years ago.
Drain tank.
Wire brush around hole(s).
Smear hole with epoxy adhesive (Araldite).
Place old style 1d piece over same (One assumes that a new 2p would work equally as well).
Wedge same into position with a stick.
Place a 100W bulb worklight immediately under this and leave overnight.
Switch off light, remove stick, fill tank.
He swears this was still going stong when he sold the car some 8 years later. Total cost 1d, 9-odd hours of electricity at 100W and some Araldite.
Tim Cuthill

Funny, I repaired the oil pan in a Nissan Stanza in a similar way.

Drained the oil, cleaned the wound. Coated a sheet metal screw with a bunch of RTV silicone (race orange, yet) and screwed it into the pan. Let it dry a day or so, refilled with oil and on I went. It was intended as a temporary fix until I could get another pan and take the time to replace it. Thing is, it never leaked a drop. Stayed that way until the car was smashed into, a few years later.

As a junior mechanic, I was once ordered to coat a sheet metal screw with epoxy and screw it into a leaking gas tank. (The leak was in the bottom. It was a messy job, which is why they gave it to me.) We warned her it was just to get her wherever she was going, not a permanent fix. She never returned to let us know how it came out. I often wondered if some errant epoxy would make it into the fuel pickup.

Ah, glory days...
Matt Kulka

This thread was discussed between 25/09/2002 and 30/09/2002

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.