Glass bead the inside of a HD gas tank or just clean up the worst?

[KNUCK]

So the paint on the outside is good and the tank steel is solid, but the inside lower portion has some fair to minor surface rust. I put in some nuts and solvent then shook it up and that loosened up all the scale pretty good. Wondering if I should glass bead the inside, I think I could get most of the remaining rust off that way. But concerned if I could get all the glass beads out with a good solvent and gas flush. Retired race bike not a driver. Has anybody done it that way???.

[pisten-bully]

Dunno HD tank insides, but my Indian tanks, with baffles and other nooks and crannies are still spitting out the occasional walnut shell fragment from my blasting them inside 10+ years ago. Take that for what it's worth, I felt good about how rigorously I cleaned them afterwards, but I was also anxious to get them on the bike and use them!

[joe fxs fxr]

I wouldn't - I'd just use one of the swish methods of surface rust removal. Maybe even just flush with gas a few times?

[PaulCDF]

I would stay away from glass beads last H-D tank I did I used an assortment of hardware: dry wall screws, nuts, a short link of dog chain and even some small rocks. BUT before putting anything
in I counted and made a record of it, like: 7 drywall screws, 6 square nuts, 10 rocks . . . you get the idea. Then when I would drain the tank I had on old screen sieve I'd dump everything in to
make sure I got all my "hardware" an rocks back.

[Skirted]

I'd probably only glass bead if you had to seal them. I have glass beaded tanks and with a lot of patience was able to flush/blow them out thoroughly. Hard to say without seeing. Would one of the rust neutralizers work? If its not scaly rust that would flake off could it be more of a visual issue than functional issue and maybe be fine as long as there is gas in it?

[chuckthebeatertruck]

This is a perfect use of plain, white vinegar.

Fill, cap, wait five to seven days.

Rinse, dry, and immediately wet down with your favorite oil film.

no rust, no paint damage, no work.

[rms337]

This is a perfect use of plain, white vinegar.

Fill, cap, wait five to seven days.

Rinse, dry, and immediately wet down with your favorite oil film.

no rust, no paint damage, no work.

+ 1 on the vinegar. I have a set of old tanks that I will be doing this too, but am considering electrolysis before the vinegar to get the heavy stuff out. You can find a bunch of videos on Youtube searching for "motorcycle tank electrolysis".

[T. Cotten]

Aquarium gravel, Folks!

I tumbled tanks at one rev per second, but even with vinegar it took days....

TUMBLER.jpg

Vinegar often leaves a black residue, which I tumbled out with a slurry of cracked corn and baking soda.

.....Cotten

[chuckthebeatertruck]

+ 1 on the vinegar. I have a set of old tanks that I will be doing this too, but am considering electrolysis before the vinegar to get the heavy stuff out. You can find a bunch of videos on Youtube searching for "motorcycle tank electrolysis".

totally unnecessary to treat the tank to electrolysis and vinegar as either will work well on their own. In my experience, vinegar does not, at all, care how much rust there is in the tank. You simply leave it longer. You'll also know how much garbage is in the tank by the color of the vinegar. Many older fuel additives turn the vinegar orange or leave the black oxide mess that Cotten referenced. I find that if I clean the living hell out of the tank first, I get most of that stuff out before vinegar soaking. I normally can reuse vinegar once or twice if I filter out the particles -- the exception being if it takes on that orange tinge. At that point, the PH is shifted enough that it just doesn't "bite" the rust.

Recently, I was dealing with an original paint '49 Moto Guzzi tank that had been left dry for 30 years - the rust was extensive inside and baffles to boot. What made it worse is that the oil tank had been stripped and also left bare inside and out for 30 years. I submerged the oil tank in a 5 gallon bucket of vinegar for 10 days and the tank was filled with vinegar for a total of 15 days -- about double the longest I've ever had to go. Tanks came out rust free.

I did try a "new" trick gleaned from another post on here and instead of swishing the tanks with mineral spirits and oil, I used Ospho. It worked a charm and the tanks did not get any flash rust. Made it super easy to paint the oil tank as well -- and the oshpo posed no danger to original paint on the fuel tank.

Like Cotten, I've also "tumbled" my fair share of tanks. I just tend to use the dryer:
https://forum.antiquemotorcycle.org/...736#post286736

[T. Cotten]

...Many older fuel additives turn the vinegar orange or leave the black oxide mess that Cotten referenced....

T'aint just gas nasties, Chuck!

Tossing anything rusty red in the vinegar bucket turns it black, probably some kind of iron acetate.

Sometimes it will scrub off. Sometimes.

....Cotten
PS: The price of white vinegar has doubled!

[KNUCK]

Thank you for all the great suggestions. I will not blast the inside just too much risk of left over media. Cotten that is an amazing contraption you have come up with, my arms are a little tired and that would be the answer if I did any more. One guy even told me to put in nuts and solvent then wrap the tank with old carpet and put in the dryer for a while. Not sure when my wife will be going out of town so will finish up by hand.

[T. Cotten]

...One guy even told me to put in nuts and solvent then wrap the tank with old carpet and put in the dryer for a while. Not sure when my wife will be going out of town so will finish up by hand.

She better leave for at least a week, Knuck!

I started out with a Red Devil paint shaker, honest.

A home dryer means the tank has to tumble.

A laundromat dryer stuffed with padding would be safer; How many quarters you got?

.....Cotten