need of knowledge

[frank horton]

fairly soon I will need to make a mirror pair of fuel tanks for this m/cycle.......
they are not made as copies in India or elsewhere.......had a few totally stupid quote so will have a go myself.....
The main idea is not to have it full of welds and tons of body filler......
would like ally but dont have a TIG but I supose could get it done......
or sheet metal....0.5mm.
my next try would involve glueing loads of wooden blocks together to make beating block......only trouble with that is I need a left n right....
any good/better ideas out there....

 

[8ob]

Make a mold and cast them in Ali

Bob

 

[Rannsachair]

I assume the pre war Indian Chief repro tanks like https://www.indiamart.com/proddetai...s-fuel-petrol-tank-brand-new-20914731591.html could not be modified to suit?

 

[arther dailey]

I like the idea @8ob of alli , along the same lines what about fibreglass , my thought being where as the tin one will rust through standing half full 95% of its life putting rust particles into the fuel/engine fibre glass wont , so although not a prefered idea on a proper restoration long term it could be the better idea for the bike ? unless there is some truly great liner to pour into a metal one these days that doesnt degrade/

 

[Onoff]

Do you have existing but absolutely knackered tanks currently?

I believe that in the early days, Expressed-Steel Panels made moulds from what was essentially ultra tough concrete, to then shape the metal round.

Could you fill the tanks with "something" similar then cut the tank off the mould in two halves?

 

[Onoff]

What about.....square / flat faced tanks with say a 3D printed outer cover?

They did something similar on Vintage Voltage where the battery back replaced the engine, I think it was an old BSA. They then printed a facsimile of the original engine, essentially a battery cover.

 

[Nomad]

Someone I know hand formed a matched pair of front wings for a 1930s car (very flowing style, tapering to the running boards at the rear). I think he used basic panel beating tools and an english wheel
He made a frame to hold a set of templates to check the profile of the wing as it progressed.
When the first wing was complete he stripped the frame then reversed the templates, and used that when he built the other wing as a mirror image.
The whole rebuild was a long term retirement project over many years but I'm sure the wings could be made a lot quicker if needed, but I'd still expect the first attempts will take quite a while to get to a decent standard.

The frame looked something like an uncovered aeroplane wing but each "rib" was made as a cross-section of the finished wing (or tank in your case).

Good luck, keep us updated

 

[Onoff]

I grew up with a lad in Kent. We reconnected years later on a Capri forum. Now a fabrication / TIG guru living in Oz. He could do it.

The simple stuff.

This custom Capri quarter panel from scratch involved much wheeling:

 

[AndersK]

This is a quite simple method how to create a shape pattern and how to mirror it.

You were on the right path mentioning wooden blocks as well as Nomad showed.
Make a sectioned buck of one of the halves. Cover it with two layers of packing tape. The glass fibre reinforced version works best but even painters tape will do but need gentle handling. Make second layer about 45° against the first. When you lift it off the buck you have a perfect map of where you need to shrink and stretch.
I usually make two of these or make the second from paper which will serve as a cut template. If working with rape pattern, where you need to cut it to lay flat is the areas you need to shrink. The opposite shows areas to stretch.

When one side is done you simply push the tape pattern to flip inside out, now you got your mirrored pattern.

When you have shaped the sheet so it fits the pattern youre almost done and just need to manipulate it a bit to get into arrangement by simply bending or "massaging" it.
Another helpful tool is to make contour gauges, a strip of metal you shape to fit the buck a chosen locations.

Pics shows what I try to describe, a simple example where both halves are identical but works the same.
Both halves were welded together and planisher. Just some high build primer used, no filler, prior to paint.

 

[Matchless]

I would fabricate it as one tank, then cut in half to ensure they matched,

 

[AVI_8]

This is way above my skill set but it’s interesting to see how it can be done just with tools and a welder
part 1

part 2

 

[AVI_8]

What a cracking bike, very rare, must be worth a small fortune now

 

[colnerov]

Hi, I've put this video before, but it's a joy to watch. -

Colin

 

[stuvy]

If I was gonna make it…

I’d get some one to draw it and get it printed so I was happy with the shape

Then make an mdf block as a former even out of server so pieces glued and dowelled together and form some ali or steel over it

Add a baffle and if it was steel I would do it myself if it was Ali I would get someone else as I’m not as good with thin Ali as I’d like to be

It’s a hard shape to mirror it nicely

Will be following along as I love bikes with this shape

 

[m_c]

I wonder how 3D prints would hold up being used as a manual former for panel beating?

 

[AndersK]

One offs for aluminium probably. Shrinking steel, probably not

Tempted to give it a try though

 

[mike 109444]

Should be possible with a manual mill may be.

 

[Ali]

Allen Millyard has some good videos on this sort of thing.

 

[Maker]

This is way above my skill set but it’s interesting to see how it can be done just with tools and a welder
part 1

part 2

Beat me to it, I want just scrolling down to say you wanna watch some Ron Covell videos.

 

[pedrobedro]

along the same lines what about fibreglass

Fibreglass rots with the ethanol content in modern fuel, seen it happen to a few motorbike tanks and it blocks the jets in carbs or the injection system.