Fuel Resistant Finish

V

Vince

Hero member
I have an Aircraft style filler cap fitted to my 3c. The bit bolted to the tank top has the lower section in contact with the fuel. When I first fitted it I had it Powder coated to colour match the 2 pack paint the tank is done with.After a couple of years the powder coat got soft and blistered and pealed off.I am looking at fixing this and was thinking I might get it Anandised red so its at least heading closer to match the tank colour.I expect if its painted with 2 pack I will get the same pealing that happened with the powder coating.BTW its alloy so anadising will work.So whats the best at being modern fuel resistant proof as a coating.
 
Dellortoman said:
You'll need to get ell the powder coat off first. That could be a pain in the arse job.
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Find a paint stripper with Methylene chloride as an ingrediance. I stripped my powder coated frame using it and it was fairly easy.
 
was your powder coated frame actually stove enamelled ? I too have found that powder coat can be an female dog to remove.
CLEM
 
The fuel has done a good job of stripping it already. I was thinking anodising would be best. The reason why I did this years ago as I was sick of fuel leaking out of the original cap when the tank was really full and on braking hard. This was pre-internet, and before I saw one of those rubber hat like things that sit between the tank and original cap that stop leaks. Marty has one made out of alloy.That would have saved a lot of fucking about with this. I was telling Sasha about these gadgets on a recent ride.
 
CLEMTOG said:
was your powder coated frame actually stove enamelled ? I too have found that powder coat can be an female dog to remove.
CLEM
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Defind stove enamelled?

I wouldn't put stoved enamelled in the same cup as powder coating. My frame was powder coated as is 99.9% of discussions related to powder coating.

I'm not a fan of powder coating
 
Vince said:
... one of those rubber hat like things that sit between the tank and original cap that stop leaks.
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There was one of those rubber top-hat things in my Jota tank when I bought the bike. The cap leaked like a bastard. I took the rubber thing out and it was fine. Doesn't leak a drop.
 
I liked to brim my tank when i first bought it .Soon leaned that would result in a solid flow out of the cap.I havent tryed one of those anti leak things but others tell me they work.BTW isnt there 2 ways the caps open,hinged either front or rear or am I as usual got this wrong.
 
Thought you had an aircraft stile fuel cap fitted or are we talking about your Ducati? Cap were hinged both ways Vince but I have no idea which models came with which orientation.
 
They original cap leaked like crazy and that's why I went Aircraft style. It didn't leak but the breather I had to add did. I have found one that has the nut on the outside so I can nip it up if it losens. The internal nut on the breather it has now needed the aircraft cap unbolted to get at it. I wish I had found an easy fix for the std cap 15 years back.
 
Vince said:
I liked to brim my tank when i first bought it .Soon leaned that would result in a solid flow out of the cap.I havent tryed one of those anti leak things but others tell me they work.BTW isnt there 2 ways the caps open,hinged either front or rear or am I as usual got this wrong.
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No your right Vince, early 3c's had the cap hinged at the front, shortly thereafter, maybe 75? they changed to rear hinge.
Apparently it made all the difference and sales went through the roof.
 
Ditto with 750s - SF/1/2 front hinge, SF3 rear hinge ... or the other way round - can't be arsed going out into the rain and hail to check in the garage!

My fuel cap NEVER leaked and I never replaced the seal. Used to fill it right up to ensure long range. All paint must be removed from the surface of the filler that mates with the cap seal. I'm putting a Kwaka flush filler on the SFQ - pretty sure the Jap bikes don't have the leaky boat issue.

Be aware that petrol in the ground tank is probably heaps colder than once it reaches your tank. If you fill it to max it will expand quickly and start overflowing. In proddy endurance races they used to chill the fuel to get more in but they'd quickly counteract the expansion by thrashing the ring off it!
 
The important thing is not to fill above (or too close to) the vent hole in the side of the rubber top-hat. Otherwise expansion will force the fuel straight up and out the top.

I seem to remember that fuel can expand up to 8% from a cold underground forecourt tank to sitting in the bike for a while and warmed up.
 
Another trick is to fill to the brim, but not close the tank cap until you have paid your money, put your crash hat and gloves on, sat astride it, and then 2 seconds before you re-start the motor close the cap, the fuel level will be the same as when you put the filler back in its stirrup, I have no idea why the hot ambient temp or residual engine temp, cause the fuel to expand when the cap is closed, but doesn't when it is shut,
Cam will know, that almost a dead certainty.
CLEM
 
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