Japan drop-tank material ?

[Aardvark]

Hi, all!

 

I'm absolutely not understand in this thematic, so if this has already been discussed somewhere in topic BM, sorry, but the search did not find anything.

 

So, what was the material of the Japanese tanks: aluminum, fiberglass, cardboard?  Or did different firms do it differently?

 

What is the question for?  During storage, the drop-tank still receive damage to the paintwork, therefore, aluminum peeking out from under the paint, if the tank was made of fiberglass, will look somehow wrong.😁

 

 

B.R.

Serge 

[Toryu]

It depends...  Some were metal tanks, some wooden.  They did rarely (basically not all) show any signs of chipping because they came out of production and were expensed on their first mission. Training units used them longer, but still no wear, just dark scratches and signs of spilling gas around the filler.

The metal tanks were usually pre-painted with the typical rust brown primer and then received a coat of the underside colour. Exceptions were late JAAF tanks which appeared in a yellow-greenish overall coat, and IJN wooden tanks which were sometimes painted with a dark varnish (black and/or dark brown?)

 

Let me know about which aircraft you inquire and I might be able to give you more precise information.

 

Michael

[Aardvark]

31 minutes ago, Toryu said:

Let me know about which aircraft you inquire and I might be able to give you more precise information.

Kawanishi N1K1-Ja Shiden Type 11 & Kawanishi N1K2-J ShidenKai.

 

34 minutes ago, Toryu said:

They did rarely (basically not all) show any signs of chipping because they came out of production and were expensed on their first mission. Training units used them longer, but still no wear, just dark scratches and signs of spilling gas around the filler.

1. After completion of production, should the fuel tank be checked for leaks?  To do this, it must be filled with liquid fuel (?) (Water is not suitable because it has different characteristics compared to fuel ?!) after the liquid from the tank is drained and it is accepted by a representative of the military commission as suitable for operation? Is there any NON-CRITICAL damage to the paintwork?  I think it's possible....

2. After the plant, the drop- tank is transported directly to the consumer, that is, to the airfield.  Depending on the type and time of transportation, by train or car, in a closed carriage or on an open platform of a carriage or car and, accordingly, weather conditions, the drop-tank is also exposed to a certain environmental impact. It is commonplace that suspended tanks are taken from the factory to the airfield, on racks, in an open platform in dry weather, in a convoy of trucks.  Naturally, upon arrival at the airfield, such hanging tanks will be covered in road dust. Will they all be wiped off from road dust?  I dont know.  Are the tanks covered during transportation with caps?  I don't know, but why?  Fuel tanks are consumable items for single use.

3. Fuel tanks have arrived at the airfield, where they are kept empty for some time. From what I saw in the photos of modern airfields, fuel tanks are kept in the open air.

I do not think that the attitude towards consumables, which are outboard fuel tanks, has somehow changed for the worse since those times.

Therefore, they are also affected by the weather?

4. After being suspended under the aircraft, the drop-tank is filled with fuel.

After that, the plane can either take off or be at the airfield for some time, on alert waiting for the command to take off, depending on the tactical situation. In this case, the inevitably spilled fuel during refueling will somehow get airfield dust either from the wind, or from other aircraft taking off, i.e.  the drop-tank will be dirty.

 

Thus, a disposable drop-tank should theoretically have some paint chips and traces of exposure to dust and dirt during transportation and storage, and traces of contamination from fuel, in real conditions?

 

Of course, while doing this, the fuel tank shouldn't look like the Transformers team played football for them for many years! 😉😁

 

In any case,  thank You very much for your answer!

 

B.R.

Serge

 

P.S.

It's just that one of the models Japan WWII aircraft was destroyed on one of the Russian forums on the basis that its drop-tank had traces of contamination ...

[Toryu]

34 minutes ago, Aardvark said:

Kawanishi N1K1-Ja Shiden Type 11 & Kawanishi N1K2-J ShidenKai.

400 l presumably wooden tanks painted in underside J3 grey. Contemporary photos don‘t show any wear, just some smears, otherwise they look brand-new. I guess they were delivered in crates.

 

Sources -

FAOW 53; Aero Detail 26; Gakken 24

[Aardvark]

1 hour ago, Toryu said:

underside J3 grey.

For this colour best Tamiya XF-12 J.N. grey or Gunze Sangyo H61 IJN Gray?

1 hour ago, Toryu said:

I guess they were delivered in crates

Disposable drop-tank in crates, in resource-starved Japan at war? Maybe shelving and some kind of rice paper to wrap? As version...

1 hour ago, Toryu said:

wooden tanks

Do you think the primer was applied to the wood before painting?

 

Also another question, can these fuel tanks be moved manually by technicians, or in order to move them and hang them under the plane, did you need any transport trolleys and mechanisms?

 

B.R.

Serge

[Blimpyboy]

This may be of some use (it’s possibly an N1K1 series or a late model A6M family tank):

http://arawasi-wildeagles.blogspot.com/2019/12/ijaaf-ijnaf-photos-more_27.html?m=1

 

 

 

The links below don’t have any info for the N1K family’s drop tanks, but they are interesting nonetheless:

 

https://arawasi-wildeagles.blogspot.com/2020/06/ijaaf-ijnaf-drop-tanks-pt-1-nakajima-a4n.html?m=1

 

http://arawasi-wildeagles.blogspot.com/2020/07/ijaaf-ijnaf-drop-tanks-pt-2-mitsubishi.html?m=1

 

https://www.awm.gov.au/collection/C1071415

 

https://pacificwrecks.com/dataplates/ijn/a6m/droptank/droptank-front-doan.html

(data plate from an A6M drop tank)

 

https://www.macleayargus.com.au/story/3738408/from-zero-to-hero/

 

and

(this is for what is claimed to be an A6M tank {I’m doubtful} made mostly of wood)

 

 

 

 

Edited August 11, 2020 by Blimpyboy

[Blimpyboy]

On 8/7/2020 at 6:35 AM, Aardvark said:

Also another question, can these fuel tanks be moved manually by technicians, or in order to move them and hang them under the plane

Probably best done when empty!

 

Edited August 11, 2020 by Blimpyboy

[Aardvark]

4 hours ago, Blimpyboy said:

This may be of some use (it’s possibly an N1K1 series or a late model A6M family tank):

http://arawasi-wildeagles.blogspot.com/2019/12/ijaaf-ijnaf-photos-more_27.html?m=1

 

Very interesting.

How You think, this chips (or mud?):

 were obtained during the war period, or already in the post-war period of storage?

About "this N1K1 drop-tank or not?"...I'm not a expert, but where two "V" struts (typical for drop-tank N1K1) on this drop-tank or traces of their attachment?

 

4 hours ago, Blimpyboy said:

Probably best done when empty!

Ofcource, nobody will not carry a full drop-tank,

but when I asked, I had not the slightest idea of the tank's construction, its materials, or its weight.

 

B.R.

Serge

[Blimpyboy]

55 minutes ago, Aardvark said:

chips (or mud?)

I suspect (and it's purely guesswork on my part) that the spots on the top of the tank are mostly due to staining of the paintwork, from something that may have been spilled on it and then seeped into the paintwork. The spotting on the bottom looks rather like mildew (or something similar) to me!

I think that all the staining is due mostly to the age of the tank, and its storage conditions.

 

Having looked a bit more, I do now think that the tank is from a late model A6M, rather than an N1K (I'm not really au fait with drop tanks).

 

Still, I would expect that any drop tank would, over the course of their life, be subject to staining from petrol/oil spills, chipping and denting from stones being kicked up on take/off landing, and slight scrapes and more denting from rough handling by ground crew.

 

I must admit, having looked at the A6M drop tank data plate (here: https://pacificwrecks.com/dataplates/ijn/a6m/droptank/droptank-front-doan.html), l was a little surprised at the empty weight of 32.5 kg!

 

Edited August 11, 2020 by Blimpyboy

[Blimpyboy]

You can see a reasonable amount of staining - and some minor dings - on these tanks. I contend that this staining comes from general dirt and grime sticking to fuel spillage (much like you see on some diesel fuel tanks and bowsers); this would build up over time, particularly given that drop tanks could be kept on the aircraft for extended periods.

 

 

 

 

 

 

 

 

 

 

This J2M's tank has a few little dings in it:

 

Edited August 11, 2020 by Blimpyboy

[Aardvark]

1 hour ago, Blimpyboy said:

Still, I would expect that any drop tank would, over the course of their life, be subject to staining from petrol/oil spills, chipping and denting from stones being kicked up on take/off landing, and slight scrapes and more denting from rough handling by ground crew.

 

1 hour ago, Blimpyboy said:

You can see a reasonable amount of staining - and some minor dings - on these tanks. I contend that this staining comes from general dirt and grime sticking to fuel spillage (much like you see on some diesel fuel tanks and bowsers); this would build up over time, particularly given that drop tanks could be kept on the aircraft for extended periods

Thank!  This more than matches my vision for modeling a Japanese WWII  drop-tank......and all the critics who will tell me: "You painted the drop tank wrong! Because the Japanese drop-tanks were only sterile clean!"  I will sending to this topic!

😉😁

1 hour ago, Blimpyboy said:

l was a little surprised at the empty weight of 32.5 kg!

I was also surprised when I saw this, in fact, two pounds of weight if measured with old Russian weight measures or one 32 kilograms ( two pounds)

kettlebell: 😁

It's not critically difficult, but you won't drag this for a long time if you don't do kettlebell lifting:

(free internet image)

😁

 

B.R.

Serge

 

[tweeky]

Quote

1. After completion of production, should the fuel tank be checked for leaks?  To do this, it must be filled with liquid fuel (?) (Water is not suitable because it has different characteristics compared to fuel ?!) after the liquid from the tank is drained and it is accepted by a representative of the military commission as suitable for operation? Is there any NON-CRITICAL damage to the paintwork?  I think it's possible....

Now modern tanks are pressure checked with nitrogen its not explosive. i would imagine it was air back then.... why would want to use water ? that's the last thin you want in a fuel system/ 

[Toryu]

Well, if you build an N1K2-J then you will have to look at pictures of drop tanks on this plane, which was basically only used operationally by the 343rd Kokutai. A wooden tank wouldn't have any dents.

[Aardvark]

2 hours ago, tweeky said:

Now modern tanks are pressure checked with nitrogen its not explosive. i would imagine it was air back then.... why would want to use water ? that's the last thin you want in a fuel system/ 

I remembered the flaw detection lessons that I took 30 years ago in the course of materials science ...long time ago it's was.....If I remember correctly, kerosene, water-soap solution, water-fluorescent solution were used as primitive methods for flaw detection of surfaces for the presence of small cracks, ultrasonic checks, fluoroscopy and something else were more complicated methods ...therefore, based on my previous knowledge, I assumed that the cheapest way to test a tank for leaks is to use tinted water.

52 minutes ago, Toryu said:

A wooden tank wouldn't have any dents.

First of all very thank for You help!

Any dents from my side, only very many little chips! 😉😁 

 

B.R.

Serge

[Blimpyboy]

10 hours ago, Toryu said:

A wooden tank wouldn't have any dents.

I pity the ground crew member who putties the ‘ding’, paints it and says it’s good to go...

[Aardvark]

On 8/11/2020 at 1:43 PM, Blimpyboy said:

 

As I understand, are there traces of engine exhaust on the landing gear and also on drop-tank?

 

There is really one interesting  nuance .... N1K1 & N1K2 also had engine exhaust pipes that were located at the bottom of the fuselage, therefore, if the engine was tested before flight with a suspended tank and for some reason the plane remained at the airfield (for example, takeoff was canceled) then the tank should be  traces of engine exhaust?

 

B.R.

Serge