Alloy Fuel Tank Fabrication

[BAHNZY]

I’m sick & tired of chasing down plastic fuel tanks that are either faded & require a month of Sundays to recover them, only to see them go back to the original state 12 months later (or) they crack after being put back into service. I had a thought that fabricating a replacement tank mimicking the original from aluminium would be a better longer term solution. I’ve tried to come up with patterns but I get out of my depth when it comes to patterning off the original tank given that you are working from the outside surface of the tank not the inside. Trying to deduct the thickness of the tank in various points from the alloy plate whilst maintaining the compound bends is just too difficult and time consuming for a backyard fabricator like me.

I then had a thought that if I sacrificed an old (damaged) tank and filled it with concrete utilising a vibrating bench to remove all the air trapped in the tank, allowed sufficient curing time then cut away the plastic I would have a buck to work from. This would allow me to shape/fabricate the sheet using an English wheel to get the compound shapes then it would be a simple matter of having someone weld the fabricated pieces together.

Thoughts?

[Slakewell]

The only guy who I know of who can shape up something like this is Scotty from Scotties choppers the guy is a true artiste. If you need to sand the welds afterwards your going to need to weld both sides. Good luck.

[odd1]

Chris amber fabrications in the UK send him the tank he will copy it
made a tank for my SWM 

[Momus]

Bahnzy
I made some car dry break fuel valve equipment at one stage. Part of the job was forming the female on-car receivers from light guage aluminium sheet into a streamlined shape that promoted maximum flow.

These things are concentric so could be metal spun to a starting shape but because they had a belly they couldn't be finished without another process.

What I did was to make a 2 piece cavity die that the blanks fitted in and then used water via a  head set up attached to the die with piston sealed by a 2" brake caliper seal in a hydraulic press to form the finished shape. I just forced the piston into the job which had been sealed and filled with water. Lot of pressure but no explosion risk. Worked well and reproduced the shape of the die faithfully.

I've thought about doing a tank or two for myself in a similar way. I think concrete or plaster would make a fair buck but I would be considering making a pourable resin item and then casting that in aluminium for the working part.


To help finishing the roughed shape to a faithful shape I would make a heavy duty split mould from fiberglass conforming to the outside shape of the tank and use the piston method or a high pressure washer to finish expand the blank. The starting buck and hence the blank would have to be made so it fitted into the finishing mould, so would not necessarily be the same shape as the original tank.

1.2 or 1.6 '0' temper 5005 al. would be a start point for material

[Momus]

Chris amber fabrications in the UK send him the tank he will copy it
made a tank for my SWM

He might be the "bloke in England" that did Troy Bondarenko's KX500 tank.

[GD66]

Chris Ambler. With an L.   

[KTM47]

kdx 175  (Russell Brown) who has cast new clutch covers etc for CR 125 and 250 has cast a alloy petrol tank for his KDX175.

I don't know if he wants to do anymore but try him.  He is also on facebook 

[BAHNZY]

The only guy who I know of who can shape up something like this is Scotty from Scotties choppers the guy is a true artiste. If you need to sand the welds afterwards your going to need to weld both sides. Good luck.

If I did such a tank I’d be going with the welded look as a finish. I know someone who can weld alloy to a finish that you would think that it was done by a welding robot. The challenge will be convincing (i.e. threatening him) to take on such a fiddly job.

[BAHNZY]

Chris amber fabrications in the UK send him the tank he will copy it
made a tank for my SWM

Odd1,
The freight alone to get a plastic tank to the UK and return an alloy unit would be double the budget I have in mind, and that’s before I even talk $’s on the fabrication of the tank itself. These are race/ride bikes & I’m trying to do this at a cost comparative price to that of buying and restoring a plastic tank. It may be a foolish belief that it can be done, but I’m going to give it a try. I’m going to the VETS MXDN this year so perhaps I’ll look this bloke up and see what’s on offer.
Rod

[BAHNZY]

kdx 175 has cast an alloy petrol tank for his KDX175

KTM47,
I’ve seen Russell’s work & it fair to say that it’s nothing short of incredible.
I’d be wondering how durable a cast alloy tank would be in the long run?
(&)
What sort of weight it would end up being?

Rod

[Momus]

kdx 175  (Russell Brown) who has cast new clutch covers etc for CR 125 and 250 has cast a alloy petrol tank for his KDX175.

I don't know if he wants to do anymore but try him.  He is also on facebook

This would be a joke for a dirt bike, if it exists. I've seen cast  Harley tanks, but on a KDX? They end up being about 6 mm thick.

[smed]

This guy made the ally tank on his CR5Hungy, I was checking it out at Heaven's Cessnock round last year whilst on hols up there,It's a great job, He was also at the PC nats at Ravo,
 I said g'day & we had a quick chat, Dunno his name though, He may be worth talking to Bahnzy,someone from heaven will know him

[KTM47]

kdx 175  (Russell Brown) who has cast new clutch covers etc for CR 125 and 250 has cast a alloy petrol tank for his KDX175.

I don't know if he wants to do anymore but try him.  He is also on facebook

This would be a joke for a dirt bike, if it exists. I've seen cast  Harley tanks, but on a KDX? They end up being about 6 mm thick.

All I have done is pass the info on.  At the very least Russell is capable of making a patent to use to produce an alloy welded tank.  There are also youtube videos on making alloy tanks and there are companies in India that make them for Classic Road Race bikes.

And of course you can buy them for Maicos.  You can buy everything for Maicos.

[Nathan S]

The #97 belongs to Lard. His mum calls him Craig.
Pretty sure one of his mates made the tank. It was a big job.

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I'm reliably told that there's a resin that is strong enough to be used as both buck and die for moderate production runs.

[Rossvickicampbell]

I would think not cheap - although using your own labour would be helpful there.  I bought one for my 1980 CR250 from Japan - absolute work of art with a price to match - understand mark up but still would of cost him a bit to do.