CB550 Petrol tank leaking - hairline opening worn in the under side

[zebedee85]

I have a CB550F1 - I believe the F and later K's to be the same but I could be wrong.

I'd go for this http://www.ebay.co.uk/itm/Honda-CB-550-K-Petrol-Tank-/263189194643?hash=item3d474c6793:g:zV8AAOSwmPdZrwJu if it weren't for the fact that I'm waiting to find out if the guy is gong to find me a replacement and pay for it. It all gets a bit complicated. Or I could just buy this and spend me own money and forget it. Not ideal though.

[Trigger]

Make sure that they are not bidding against you, as he won't find a good replacement that easy. Don't let the muppet  get away with it, any good welder would know not to weld any sealed container.

[florence]

I've lead soldered a tank before with a blow torch but left the lid open.  I put the empty tank out in the sun for a few days with lid open and to check, put my nose in the hole before I started.  All fuel had evaporated.  Do not use detergent, it can form an emulsion with the residual fuel and trap it into the container rather than wash it out.

Also, I have sucessfully repaired a leaking seam on a tank with araldite, it seems completely inpervious to petrol.

No one should apply heat to a sealed box.  Perhaps they are too young to remember what a steam engine is.  I hope you are properly compensated.

[zebedee85]

Here is the damage

[hairygit]

Ooh, one seriously obese looking tank!

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[Tomb]

Yep, unfortunately that's a skip job, the top is wrecked too.

any good welder would know not to weld any sealed container.

+1

[Trigger]

That welder needs to go back to college and listen this time.

[zebedee85]

We reached an agreement. I have decided to purchase a NOS from CMS. I must be insane.

[hairygit]

You'll have to be quick, only one left!

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[AshimotoK0]

A few tanks here

https://www.ebay-kleinanzeigen.de/s-cb550-tank/k0

[zebedee85]

Well - for those interested, I have the bike back on the road, and ironed out the issues from the top end rebuild. New tank is fine (though I had to steal the 750s petcock because the old tank had a different size one. From when I bought it, a fairly well preserved example which ran like crap and leaked oil from many places to oil-tight nearly-new performance:

https://youtu.be/jMd8tn1D8Bo

[Trigger]

Looks and sounds sweet  I am doing the later F2 at the moment and can't find a OEM exhaust system for it.

[zebedee85]

I live in fear of the day that mine gives up the ghost, or I damage it. Now with motad out of business...

[Trigger]

I live in fear of the day that mine gives up the ghost, or I damage it. Now with motad out of business...

A lot of people remove the OEM pipes and fit a Motad, which are still available at some parts suppliers. There is a member on here that had a stainless steel one made to original spec.
Here is a very nice one but, still on the bike >>> http://www.carandclassic.co.uk/car/C913871

[toucheturtle]

First job I had when I left school was working at a petrol tank laminators. Back then you couldn't get pattern tanks and manufacturer's new tanks were too expensive. We were mad busy all day every day, there was a massive diesel powered pressure washer which I used. It had a detergent tank and produced high pressure steam. We'd remove the petrol tanks, take out the senders and thoroughly wash and rinse the tanks out, grind off all the paint, braze any holes or plate large patches and then laminate the whole tank in fibre glass mat and then tissue, finish off painting in gloss black.

The end result used to look pretty good but when pattern tanks came out they were more or less the same price, still did the odd car with a rare tank but eventually the firm folded. In the time I was there despite all the precautions we still had two tanks explode. One time we ran out of detergent & diesel so I was told just to give the tank a thorough wash with the steam cleaner set to high pressure cold wash. The welder lit the oxy/acet torch and went to scrape the torch tip on the tank filler pipe. Bang, the tank ripped apart at the seam and he suffered flash burns to his face and hands, all his hair and eyebrows singed off. Obviously I got the blame and a good bollocking. Made me very cautious when I started welding them.