Hi All,got some corrosion under the paint on the tank just in front of the filler what's the best way to tackle that?.Looks odd the way it's turning to a white powder,is the tank made of aluminium?,cheers All,Artie

Artie66,

Yes, the tank is aluminum, what has happened is that water in the fuel, being denser than the petrol, settles at the lowest point in the tank. Over time it oxidises the alloy, turning it to a powder like state in molecular sized corrosion leading to a tea bag effect where the eater settles.
I've just repaired mine. You only need to clear the area affected where the paint is bubbling, back to the alloy, then using a fie tip on a Dremmel, carefully clean out the corroded holes. This led to me having several holes, no larger than 3mm diameter to fill. I used a 2 part plastic padding fuel tank repair sealant. Goes off after 5 mins and you can sand it down easily. After coats of primer AMD filling inbetween coats, just used a spray can and laquer to finish.
USE CARE WITH THE TANK ! DRAIN IT AND LEAVE IT A COUPLE OF DAYS TO EVAPORATE ANY FUEL, THEN I FILLED THE TANK WITH CO2 FROM A FIRE EXTINGUISHER BEFORE CLOSING THE FUEL CAP.

Have a look at the thread on my repair here

I used devcon because I had it in the workshop but there are many products that will do the job.
88KE

Cleverbee wrote:Artie66,


USE CARE WITH THE TANK ! DRAIN IT AND LEAVE IT A COUPLE OF DAYS TO EVAPORATE ANY FUEL, THEN I FILLED THE TANK WITH CO2 FROM A FIRE EXTINGUISHER BEFORE CLOSING THE FUEL CAP.

If you were concerned about a spark from the grinding it isn't a problem as you cant get a spark from aluminium. But it was good thinking to do that

It was the motor on the Dremmel that was my concern...

Thanks guys,great advice,tank came with the new(to me)bodywork which is all colour matched so would be nice to put it all on.Will have to do the prep work on it and see how bad it is.Tank that came with the bike is thankfully in better shape.

88KE,many thanks for the thread on your tank repair,looks like the biz stuff to use for sure!

artie86 wrote:88KE,many thanks for the thread on your tank repair,looks like the biz stuff to use for sure!

No worries Artie. That product only comes in a 1 litre tin so its expensive. There are some links in the thread to other less expensive products.

88

You're a goodun,will follow that thru' and have a look,thanks my friend

Picking up on an old thread

Anyone used solder to fill small holes in K100 tanks?

Regarding residual tank / fuel fumes, a friend of mine sent his off for TIG welding and he was told to insert the end of a car exhaust pipe into the tank for a few mins.

Regards

GF

Guy I tried using ally solder on aluminium and it wasn't a success. There seems to be a fine line between getting it to run and adhere and blowing a hole. I tried oxy acetylene and a MAP gas torch. When I decide to get oxy back again I'll try again with thicker ally, the stuff I was  practising on was pretty thin.
Regards Martin.

Hi to GF/MW I Have had good results in the past,the trick is cleanliness,lots of fluks and WAFT the flame rather than hold in one place as for FUMES use a kettle  to put steam into the tank to remove petrol fumes.An old plumbers trick for smoothing/spreading the solder is use leather treated with fluks.Best of luck.

PS As for car exhaust CO2 gases might be why but im not sure.Steam is 100%safe