Rusted fat bob gas tanks...

[Steve Galli]

Hi all...
Any ideas on cleaning the inside of gas tanks...
I have one that really bad inside... full of scale and rust...it’s original to the bike and really would like to save it...
Thanks

[slamiste]

Hi Steve,
Are you concerned with saving the paint job on the outside of the tank? If NOT I've had acceptable results by:

1. Add a couple of hands full of dry wall screws to the tank and shake and rotate the tank until all loose rust that can be removed is removed. This could take a long time and likely will mean a number of iterations of empting the screws from the tank along with the loose rust and doing it again and again until all loose stuff is removed.
2. If you've been lucky with step one, the next step I take is to add phosphoric acid to the tank and go through the routine of rotating the tank to get part of the inside covered with acid, let it sit for a few hours, rotate the tank to cover another part of the tank and so on until all internal areas have been soaked. Totally drain the acid from the tanks and rinse with water a bunch of times. Force dry the tank. When your sure it dry coat the inside of the tank with a sealer such as Red Kote.
3. If you didn't get good results in step 1, I've used Muriatic acid first but in this case you don't want it to set in the tank for too long. Add the acid, rotate the tank for a few minutes, drain and repeat until you're satisfied with the results. Flush with water to get all the acid out of the tank. Force dry and go to step 2.

This has worked well for me but the are some concerns:
1. Dealing with acids can be dangerous (particularly the Muriatic). If you decide to de this you need to research personal protective safety gear and proper disposal methods.
2. There is always the chance that when you remove the rust you will find that your tank has developed 1 or more leaks.
3. If you don't follow the directions for applying the sealer TO THE LETTER your sealing will fail and cause a whole new set of problems.


Steve Slaminko

[Steve Galli]

Hi Steve,
Are you concerned with saving the paint job on the outside of the tank? If NOT I've had acceptable results by:

1. Add a couple of hands full of dry wall screws to the tank and shake and rotate the tank until all loose rust that can be removed is removed. This could take a long time and likely will mean a number of iterations of empting the screws from the tank along with the loose rust and doing it again and again until all loose stuff is removed.
2. If you've been lucky with step one, the next step I take is to add phosphoric acid to the tank and go through the routine of rotating the tank to get part of the inside covered with acid, let it sit for a few hours, rotate the tank to cover another part of the tank and so on until all internal areas have been soaked. Totally drain the acid from the tanks and rinse with water a bunch of times. Force dry the tank. When your sure it dry coat the inside of the tank with a sealer such as Red Kote.
3. If you didn't get good results in step 1, I've used Muriatic acid first but in this case you don't want it to set in the tank for too long. Add the acid, rotate the tank for a few minutes, drain and repeat until you're satisfied with the results. Flush with water to get all the acid out of the tank. Force dry and go to step 2.

This has worked well for me but the are some concerns:
1. Dealing with acids can be dangerous (particularly the Muriatic). If you decide to de this you need to research personal protective safety gear and proper disposal methods.
2. There is always the chance that when you remove the rust you will find that your tank has developed 1 or more leaks.
3. If you don't follow the directions for applying the sealer TO THE LETTER your sealing will fail and cause a whole new set of problems.


Steve Slaminko

Thanks Steve...
paint job is trashed.... not concerned about it at all...

[RichO]

There's an ad in the national magazine and the product is available at most auto parts stores. It's a citrus based rust remover that can be reused, is envro safe, doesn't hurt paint, and will get rid of rust. I had laced up rims that the owners before me never replaced the rim strips when changing tires and the rust had the nipples firmly implanted. I put this material in a plastic tube and rolled the wheel every now and then. presto chango in a couple of days I screw out the nipples, recaded them and the spokes, primed the inside of the rim and reassembled. Stuff works great. One of the American pickers used to be in the ad. best product ever! lot's of friends have had good luck with it in gas tanks too!