Stripping a fuel tank by dipping

[FTR]

Hoping for some advice on this. I want to get my fuel tank stripped prior to repainting. It's already been repainted by previous owners at least twice so wanting to go back to bear metal and start from scratch. A local place has offered to dip it for me in their stripping tank but it would be total immersion.

Ive removed everything from the tank but I'm concerned about the return valve or whatever it is from the fuel pressure regulator. My bike is an 83 so has a spigot for the return pipe to be connected but the part inside the tank that this connects to is not removable as far as I can see, and I don't know what's in it.  Would it be damaged by immersion in paint stripper, is there anything else in there that would make dipping it a bad idea?

Thanks in advance.
 

[Laitch]

There's just a standpipe within the tank. Check that it's open then plug it. Is the ball-and-spring assembly still withing the check valve?

[FTR]

I thought all I could see is the hose spigot under the tank and just a cylindrical thing in the tank directly above the under tank spigot position. The in tank bit has no obvious features and nothing apparently removable. I will need to take another look tomorrow as now im doubting my own memory if you think there might be some sort of Jon return valve in there :(

[Laitch]

I thought all I could see is the hose spigot under the tank and just a cylindrical thing in the tank directly above the under tank spigot position. The in tank bit has no obvious features and nothing apparently removable. I will need to take another look tomorrow as now im doubting my own memory if you think there might be some sort of Jon return valve in there :(

Don't let your heart be troubled.

The in-the-tank bit should just be the pipe. Early tanks had a check valve ball and spring assembly spliced into in the fuel return hose pipe beneath the tank floor so the pipe wouldn't leak fuel when the hose was removed from the fitting but in many Bricks the ball assembly buzzed so much the blasted spring and ball was removed. Later tanks just have the return pipe without the valve body under there.

[FTR]

Thank you, really helpful.

Attached is a photo of the inside of the tank directly above the pressure reg return. Sadly I can't get my hands in there sufficiently to feel around it and was puzzled as to what may contain. Need to invest in a dental mirror on a stick or similar.

[Laitch]

Thank you, really helpful.

Sadly I can't get my hands in there sufficiently to feel around it and was puzzled as to what may contain. Need to invest in a dental mirror on a stick or similar.

It shouldn't contain anything except an opening to the vast world below it. That's an excellent photo! let's have a photo taken from beneath the tank showing what's on the other side of the floor. Don't go to too much trouble though.

[Chaos]

It shouldn't contain anything except an opening to the vast world below it.

[daveson]

The barb and the valve are the one unit. It can be removed from the underside with a 19 mm spanner. As Laitch mentions, the cup arrangement seen on the inside only has an opening. The circular opening is on the forward side, so can't be seen from the filler opening. It's on the higher side, probably to minimise crap from accumulating around the valve. The poor resolution of the photo makes it difficult to see the opening.


IMG_20250523_162856.jpg (19.4 kB . 432x576 - viewed 324 times)

[Laitch]

As Laitch mentions, the cup arrangement seen on the inside only has an opening.

The "cup arrangement" within the tank is a pipe with an internally threaded receiver for the check valve assembly attached to its lower end. It was pushed into the hole from the underside of the tank floor and welded into position. Viewed from the fuel cap opening, the weld bead joining the assembly to the floor can be seen at the base of the pipe.

[FTR]

Thanks all for the information, very helpful.

I stripped all the gunk off the base of the tank and unscrewed the spigot from the underside and you are correct, nothing there to worry about so the tank is off being dipped/ stripped. Photo attached ... It came off very easily and there is a hole at the front (out of my view from the filler port)

[Kaos]

Better to have some info rather than non. Or better late than never.
I had mine glassbeat blasted to strip it from paint.
Also have done one by hand, rough grid to very fine grid (was also the reason I got the other blasted) because its a good day worth of work.
I would recommend an unpainted tank, finished with clear satin 2k.

[FTR]

On cleaning up the spigot thing its apparent that mine still has the ball bearing in it.

@Kaos - my tank has a bit of filler in it, so leaving it unpainted isn't going to be possible. I did think of leaving it bear - guess I could always get another tank ...

[Laitch]

On cleaning up the spigot thing its apparent that mine still has the ball bearing in it.

If by "spigot thing" you mean the one you removed from beneath the tank, remove the ball bearing and the spring, if there was one. In the future, whenever you need to remove the tank or to replace that hose, the classic method is to remove the hose with one hand and shove a golf tee in the spigot opening with the other but if you don't play golf, you can always make a custom plug from a dowel, rubber stopper, etc. If you depressurize the tank before removing the hose, there is not much fuel loss to trouble you, unless you're smoking a cigar. That's one reason why vaping has become popular.

[FTR]

Had a good look at it and it has a small ball bearing in it, but no spring. All seems in good condition. I did get the bike running when I first bought it and didn't notice any noise from it.

[Laitch]

10-4

[Duckbubbles]

If by "spigot thing" you mean the one you removed from beneath the tank, remove the ball bearing and the spring, if there was one. In the future, whenever you need to remove the tank or to replace that hose, the classic method is to remove the hose with one hand and shove a golf tee in the spigot opening with the other but if you don't play golf, you can always make a custom plug from a dowel, rubber stopper, etc. If you depressurize the tank before removing the hose, there is not much fuel loss to trouble you, unless you're smoking a cigar. That's one reason why vaping has become popular.

I think the best solution is to get a couple of straight fuel line quick disconnects from Beemer Boneyard and install them.  Took me 20+ years to figure this out.  Install them opposite each other so they can't be connected wrong.
The ball bearing in the spigot caused a rattling/hammering sound in early K100's and was removed on later models as far as I know.

Frank