Tank repair - any ideas please?

[Goofle]

Hi all,

As Mike has just posted I’ve got snags with the fuel tank on my Monstro. There’s a area about the size of my thumb nail that is leaking. It seems that the metal has just gone ‘soft’ not dissimilar to a chewing gum, and the fuel kind of oozes through. (I’ll try and post pictures shortly.) It’s not near a seam, but just in front of the seat (where a tank pad would be).
I’ve looked on the evil bay and tanks seem to be in the range of £100-£200 - but seem dented and (leak excepted) no better or worse condition than what I’ve got.
Another option would be to get the whole tank repaired / resprayed alongside the mudguard and seat cowl (if I can find it, it’s not been seen post house move).
Any ideas please?

[Nickj]

You sure it's not rusted through from the inside?
That would make it a bit soft as it would be very thin so don't go pushing too hard.
If you can get a repair done make sure that they have a good look around the hinge area which is one of those prone to failure areas due to water in the tank. This is much more of a problem now with that evil ethanol in fuel.

Good luck with the mending/replacement

[Jez900ie]

You need to first find out why it is leaking. Is it an old repair that was done with epoxy fillers? If so the old repair will need to be removed before anything can be done. its impossible to repair old expoxy that has degraded by fuel contact; it needs to be totally removed. Can you see inside the tank, or do you have one of those viewer/ cams to allow you to see?

If the tank is leaking because it has developed "pin holes" rust you might be able to apply POR PATCH directly to the pin holes from the inside. I Here is a link to their US site for info.
https://www.por15.com/POR-15-Patch-F...nd-Seam-Sealer

You can buy this on eBay or Amazon. I have used it myself and it really does work. As far as I know it is the only product that is fuel resistant -though others claim to be... Its easy to place in the right area as it has the consistency of silicone. Are you actually able to reach the area that leaks through the filler hole? If not find someone with smaller hands? Be sure to wear protective gloves as POR PATCH is not harmful, but it is difficult to get off your skin. Once dry, it is hard as steel and will give the thin metal reinforcement.

It sounds as it the exterior is currently in good shape. If I were in your shoes I would apply Helicopter transparent tape made by 3M to ensure it stays exactly as it is now - also available on eBay. Place the Heli tape as you would a tank saver, bearing in mind that it is going to be there permanently. Then provided you can see its just rust causing the problem, and you can reach it (from inside) put POR PATCH over the area and leave it for at least six days to set.

I hope all this makes sense. Its hard to envisage fully your situation without seeing it first hand. Get all the fuel out first and leave the tank a day to dry out fully to be on the safe side.

Co incidently I am selling a slightly dented & scratched 2002ie tank. A friend has first refusal and I gave him a week to decide which is up next Saturday. It is in usuable condition but you would want to get it painted at some point. It came off my own bike so I know it does not leak at all and has no rust anywhere. Still these Monster tanks vary considerably in the way they are shaped underneath so I don't know whether it is suitable for your bike!

Drop me a PM if you have any questions, and goodluck.

[chris.p]

This would be a better solution, used it on a race tank for a 600ss;

https://www.rust.co.uk/product/tank-re-new-kit-21

[BigOz]

Having done a few weld repairs to Ducati tanks I'd urge you to decide if the tank needs metalwork before applying a liquid fix or sealer.

I've had a couple where fixes were attempted in this way and it causes problems,nothing that can't be worked around but in one case it took ages to clean up the metal around the repair to avoid contaminating the weld.
Trying to remove an epoxy like finish without further thinning the already thin metal though a small hole in the tank is not fun and will cost an arm and a leg if you're paying a professional to spend the time.

I'd start by draining the tank and get a good look at the area from the inside, you might need to get a cheap inspection mirror and torch/light source you trust not to ignite the petrol vapor to see around the inside of the tank though the filler hole.

If it is going off for welding strip the parts off the tank, filler cap, pump e.t.c. so it is as open as possible and leave it somewhere warm and well ventilated and away from ignition sources (outside in nice warm sunny weather is good) for at least a week before handing it over to someone and warn them that it is a used tank that has and may still contain fuel no matter how obvious that might seem.

[Goofle]

Thanks all! I’ll be taking it to bits shortly!

[Goofle]

Right. The tank is now stripped and I haven’t learned a deal more as I can’t see inside. What I have learned however is that people seem reluctant to apply a welding torch to a metal can containing a potential petrol vapour...
I’ve taken it to my local trusted independent Ducati specialist. He’s going to have a look inside with his camera, then, subject to the inside not resembling a rusty mess braze up the hole and make it tight again. He agrees that the rest of the tank seems (from a visual external inspection at least) ok so I’m thinking / hoping it’ll be ok. From there it’s going straight to a spray company he recommends and getting resprayed. There’s a few imperfections as well as the leak site so it’s all being done. If he agrees that’s it’s viable I’m going to drop off the mudguard (bought second hand to replace one that decided to make its own way down the A69) and the seat cowl to be done at the same time.
My only concern is I’ll end up with decent (hopefully!) painted parts but a shabby frame, engine and it’ll look odd at best, ridiculous at worst!

[350TSS]

Nothing for it really, just a complete strip and total refresh ??????

[Goofle]

That’s about it. I could have left the repaired bit I sprayed I suppose but that would look daft - dafter even than immaculately sprayed red tank and mudguard on a tatty bike I think!

......easy Ian, this could be the start of something big..... look what happened to Luddite, and he aint finished yet !!

[Goofle]

Originally Posted by Moco1961

......easy Ian, this could be the start of something big..... look what happened to Luddite, and he aint finished yet !!

Ha, that would be great - unfortunately I’m short on time space and indeed skill to do that!

[Jez900ie]

f you remover the filler cap and the base it sits on you should be able to see inside like this

[Mr Gazza]

Carby tanks have a less generous filler opening than the ie bikes though.

When Monsters went to injection, an extra ring was added to the filler cap and the aperture opened so the pump would in, along with the filter and a portion of your arm.

[Goofle]

I removed the filler cap and it made very little difference to access, sadly.

[BigOz]

Originally Posted by Goofle

What I have learned however is that people seem reluctant to apply a welding torch to a metal can containing a potential petrol vapour...

More than a few have been killed welding or cutting vessels that contained flammable vapour. As I've mentioned I have the owner let the tank sit dry and vent for a week or so then I add a few more days to that once I get it. After that, if it has any significant smell of petrol it gets longer to sit and vent or completely filled with a detergent/water solution then drained and allowed to dry. Once I'm happy to start I leave a compressed air line in it on a flow of a few litres a minute using a low-pressure regulator and finally I swap to purging it internally with a good flow of argon for at least 10 minutes before I spark up, even after all that it still doesn't feel like a good thing to be doing.

Originally Posted by Goofle

I’ve taken it to my local trusted independent Ducati specialist. He’s going to have a look inside with his camera, then, subject to the inside not resembling a rusty mess braze up the hole and make it tight again.

Braze is a good repair, it allows the problem area to be closed up and reinforced without melting the base metal which if it is thin just wants to melt back and leave a huge area to repair.

Should the repair be more than they want to attempt and if the tank is essentially scrap at that point let me know and if we can get it down hear to Kent I can take a look. I'm not a professional and would do my best but I don't want to damage an otherwise repairable tank if I run out of skill.