Fuel tank sealer (again)

[coldsummer]

Sorry to raise this again as it has been discussed quite a bit recently but I'd appreciate some feedback in view of the ever-evolving ethanol issue.

I have a two-week window of opportunity coming up to get the little 650 rebuilt and had planned to use the nice red bodywork from the bike I bought from Ralph earlier in the year. However, on closer inspection it is a bit rusty and more worrying the paint shows signs of bubbling around the badge which is a known weakpoint so I figured I would go for a proper respray (I prefer blue rather than red anyway) and de-rust and seal the fuel tank at the same time. I've decided to go with Frost's Bio-rust treatment as I've had good results with that in the past but can't decide on a sealant. Frost are now selling the new and improved Por15 system but I'm a bit put off as the instructions on the website say it should be brushed on (rather than swilled around).

Any ideas before I pour a can of sealant in and hope for the best? I need to get this thing finished so I can start on the no.7 project.

[kev edwards]

Unless the tank is leaking, i would clean with the bio rust solution, rinse it wih copious amounts of deionised water and then spray loads of wd in there let it dry out and keep it filled with petrol all year round, sealants are ok all the time they stay applied to the inside of the tank but when they lift they are a bugger to clean out and reseal, more often than not resulting in a srapped tank.

[rogz1a]

I've used POR15 in my tank and although it 's only been in there a year it hasn't peeled or cracked. Time will tell if it does fail but I didn't have much choice as I had rust deep in the lower seam with pinholes in a couple of places.
I used the 3 stage system- Marine clean, Dry out the tank with a hot air blower. Acid etch (same acid which is in coke apparently) and dry out again to leave a white residue in the tank and then a tin of the POR15. This is how Frost said to do it and it worked a treat
I just took off the fuel tap and sealed the hole up, poured it in, sealed up the fuel cap end and swirled it around for 15 minutes, checking that all surfaces were covered.
Then drain the remaining liquid out through the fuel tap hole.
It worked for me but as I say only time will tell. Many people on here don't like to use it and I wouldn't have if I had the choice but the seam had already gone in 2 places so there would be a good chance that the seam could have been weak elsewhere

[uk kev]

Por15 won't lift, as it is a paint and not a resin.

I have just done my tank with the full on £65 Marine Clean 3 part kit, it was an all day job to do it correctly following the instructions supplied, but then I only want it to be right first time!

[PAULJAC47]

Cant comment on how effective these modern sealers are but i know every bike i have seen usually from the states has sealant braking off and flaking off the inside of the tank,i reckon they did it even from new over there!!

[Mark Tiller]

Unless the tank is leaking, i would clean with the bio rust solution, rinse it wih copious amounts of deionised water and then spray loads of wd in there let it dry out and keep it filled with petrol all year round, sealants are ok all the time they stay applied to the inside of the tank but when they lift they are a bugger to clean out and reseal, more often than not resulting in a srapped tank.

i would agree with this