Fuel tank/s - you really don't want to know......but.....!

[Rick Fischer]

Hello all

As most of you will be aware the bottom skin of the fuel tank is double. The inner is part of the fuel carrying tank bit and the outer/lower skin is the fuel tank locator bit which bolts the tank into the carrier and chassis outriggers.

In the attached photos (start from left) note the amount of corrosion between the the tank skin and the outer carrier skin. The really bad news is that these two tanks came from Emerald and Cooma - good inland "dry" climate. The other not so good news is that the wee capillary gap between, can be full of dust mud, and of course it will get moist/wet and take a long time to dry. In my Emerald tank case, the expanding rust scale separated the soldered attachments between tank inner and outer. This was caused by a complete breakdown of what appears to be a lead wiped tank skin. [bigsad] I descaled mine with Jason pistol lowest setting.

I can only recommend that if you haven't got a record of the tank bottom/outer skin having been removed and the bottom of the tank checked for corrosion scale and pitting, and with an appropriate repair if needed e.g. sweated gal patch/s; one may risk a catastrophic failure of the tank skin proper. :BigCry: Considering getting a new lower outer skin fabricated from gal and sweated back on would be a good idea too.

In my two cases, it will be flapper wheel back to shiny steel and then solder wipe and sweat gal patches............................then re-sweat all the folded seams.

[mfc]

Yea I'm scared to even look at mine as it still holds fuel!!

[chazza]

I glued the outer skin on with Sikaflex adhesive; so much easier than soldering.

The original tank metal was Ternplate, which was lead-coated steel and is rather hard to find now,

Cheers Charlie

[JDNSW]

Tern plate was used extensively during and after WW2 instead of galvanised sheet steel as zinc was in shorter supply than lead. It ceased being used to any extent by about 1950, perhaps because the lead plated steel cannot be used safely for anything handling drinking water - and the majority of galvanised sheet steel production is used in roofing, where the use of it for drinking water is beyond the control of the supplier. I don't know, but I would be surprised if tern plate is not banned for use in roofing in most places. Without this market - why bother making it?

[Rick Fischer]

[QUOTE=chazza;2686610]I glued the outer skin on with Sikaflex adhesive; so much easier than soldering.


At least it will never come off :0)

May end up going that way too if I can find an RTV that is petrol resistant.

cheers

RF

[bemm52]

Tern plate was used extensively during and after WW2 instead of galvanised sheet steel as zinc was in shorter supply than lead. It ceased being used to any extent by about 1950, perhaps because the lead plated steel cannot be used safely for anything handling drinking water - and the majority of galvanised sheet steel production is used in roofing, where the use of it for drinking water is beyond the control of the supplier. I don't know, but I would be surprised if tern plate is not banned for use in roofing in most places. Without this market - why bother making it?

The other day I was delving into the bowels of my shed and I came across a container we were required to make as part of my sheet metal apprenticeship training at Adelaide School of Plumbing. It was made of tern plate and was still as good as the day I made it, it had been soldered, worked for wired edge, grooved seam and knocked over bottom. Not bad for a 45year old metal object that has kicked around various sheds for 45 years. Tern sheet is a a quality material, I vaguely remember our instructor saying it was used for fuel tanks, I think he said because the lead coating was less likely to be susceptible to sparking in a prang.
You brought back memories John.....I'm pretty sure it was in Grenfell Street I remember ducking into the pub next door at lunch time with my apprentice mates every tech day

Cheers Paul

[JDNSW]

The other day I was delving into the bowels of my shed and I came across a container we were required to make as part of my sheet metal apprenticeship training at Adelaide School of Plumbing. It was made of tern plate and was still as good as the day I made it, it had been soldered, worked for wired edge, grooved seam and knocked over bottom. Not bad for a 45year old metal object that has kicked around various sheds for 45 years. Tern sheet is a a quality material, I vaguely remember our instructor saying it was used for fuel tanks, I think he said because the lead coating was less likely to be susceptible to sparking in a prang.
You brought back memories John.....I'm pretty sure it was in Grenfell Street I remember ducking into the pub next door at lunch time with my apprentice mates every tech day

Cheers Paul

My first encounter with tern plate, actually corrugated iron, was when I was a high school cadet in the mid fifties - it was used in the ablutions blocks at Singleton army camp - and it was prominently labelled '"Tern - not to be used for drinking water" on the unpainted underside of the corrugated iron roof. I had never heard or seen the word before so asked my father about it when I got home. (Like most fathers when you are that age, he knew everything. And actually had a very wide knowledge - at that stage he was teaching apprentices in an aircraft engine factory.)

[mox]

I once owned a German made Claas header (combine harvester) built about 1963. Much of the tinwork was too light for the job it was intended to do and prone to cracking. Was very difficult to make oxy acetylene welds using steel filler rods stick. I gather this was due to lead on or in the steel which was probably tern plate. Maybe this was also later banned from use where it contacts raw materials of foodstuffs - in this case grains. Note that friction of straw and grain on tinwork polishes the surfaces.

Once I did a repair job using for a bloke working for a neighbour. Metal had cracked around the lock in door on XA Falcon Panel Van with same silly long door with no supporting frame for window glass as for same model utes. After removing lock, attempts to weld cracks using steel filler rids failed. Had to remove door and position it so surface to be welded was horizontal. For me this was necessary so could use bronze, would stick despite presence of lead but for me. Much harder to make it run where wanted and stick.