Tank rust

[andyoutandabout]

Peeps,
My summer fling with the 91 teal striper was a real success and stands as testament to how solid the FJ is. The bike was in fair condition for the most part, bar some nasty looking rust in the tank. I ended up flushing this out best I could with a suggested coke and vinegar mix, though this didn't really do much of a job.
It did loosen a lot of crud, which was caught by the in line fuel filter (nice improvement Yamaha over the 86).
And the bike ran flawlessly for 6,500 miles round Europe.
In an attempt to stop further rusting during storage, I drained it and sloshed some old oil around inside to try an coat the interior.
Anyone got a fail proof tank rust removal technique?
I'm not keen on tank liners after watching Marsh pick the flakes of his liner out of his float bowls at a Petaluma rally.
Ideas welcomed
Andy

[Troyskie]

Mate, I've recently cleaned an amazing amount of rust out of three FJ tanks.

After watching a number of web vids on removing the rust, they all seemed very manual so I padded my cement mixer and dropped a few lengths of different size chain in the tank. I added a little kero to move the crud around, then race taped the tanks into the barrel of the mixer (one at a time). The petcock and sender were removed and race taped closed.

Major flushing required. I pulled about a litre, or quarter gallon, of muck out of the two worst ones. Pinholes developed in two of them. Of the three, two got a seal treatment and one was soldered.

As long as the tank filter is in you shouldn't get crud to the carbies, although the later model tank filter was missing on one of the tanks I fixed which might explain flakes in the bowls you mention.

When removing the rust, a clean, but now un galvanised tank will surface rust really quickly, flash rust I think it's called. Kero or diesel will help. but a cleaner and rust converter will be the best solution.

It will take ages and ages to get all the crap out, so be patient.

I also obsessively flushed (enough water to green the Sahara!) and dried the tanks (with a heat gun) then vacuumed them. I made a little extension hose and used my cheap arse vacuum (it died at the end) to get every last bit out. I also made a little wire extension to scrape the seams and vacuum again and again and again.

The interesting result was the worst tank cleaned up best, and the best tank had the most holes.

Also, the filler cap drain pipe runs through the tank and can catch the chain so, if you use my cement mixer method, reverse it if the noise of the chain sliding stops.

If you use washers to get into the seams wire them together with a longish fine wire otherwise you'll lose the will to live trying to fish them out.

This is a messy and very smelly process so do most of if outside if you can.

Troyskie

[red]

The bike was in fair condition for the most part, bar some nasty looking rust in the tank. I ended up flushing this out best I could with a suggested coke and vinegar mix, though this didn't really do much of a job.  I'm not keen on tank liners after watching Marsh pick the flakes of his liner out of his float bowls at a Petaluma rally.  Ideas welcomed
Andy

Anydy,

There are lots of posts here about using electrolysis to kill the rust in a tank.  Here are just a few:

http://www.fjowners.com/index.php?topic=13345.0

Tank coatings inside the tank can be very good after the mechanical cleaning and/or electrolysis, but tank coatings must be done correctly.  Oil, diesel fuel, or kerosene would be bad news, with any tank coatings.

[racerrad8]

Anyone got a fail proof tank rust removal technique?

I'm not keen on tank liners after watching Marsh pick the flakes of his liner out of his float bowls at a Petaluma rally.

Andy

Here is post from earlier this year: http://www.fjowners.com/index.php?topic=18001.msg181084#msg181084

It doesn't matter what tank sealer you use, the preparation before the sealer is applied is the key to success.

I stripped Marsh's tank after Scott bought the bike and used the POR15 motorcycle tank stripper & sealer kit: https://www.por15.com/POR-15-Motorcycle-Fuel-Tank-Strip-and-Repair-Kit

I have not heard any issue from Scott about the repairs since they were made back in 2016.

My buddy who owns the hardware store down the street is a big time car guy. He has added the KBS line of products to their inventory. I see they have a tank sealant kit as well. I will most likely try that kit on the next tank I have to do. https://www.kbs-coatings.com/large-cycle-tank-sealer-plus-kit.html

Now as far as storage, here is what I do. I grab up several desiccant bags that I collect from everything that they come in, I do not throw them away. I then wrap them in a piece of stainless steel wire around them. I hang them from the cap and then close the tank. The desiccant bags will absorb the moisture preventing future rust.

I also throw these desiccant bags in my tool box drawers. This keeps my tools from rusting during the minter months, especially the mobile toolbox we take outside in the inclement weather.

Randy - RPM

[Troyskie]

Of the two tanks I sealed, one was with POR15 and the other was the KBS Gold. Personally I found the KBS the better of the two, and quite a bit cheaper.

I've a very rough tank left over that I'm using while all my other tanks and fairings are getting a paint job.

I'm going to experiment with home brew galvanising on that one.

[red]

Now as far as storage, here is what I do. I grab up several desiccant bags that I collect from everything that they come in, I do not throw them away. I then wrap them in a piece of stainless steel wire around them. I hang them from the cap and then close the tank. The desiccant bags will absorb the moisture preventing future rust.  I also throw these desiccant bags in my tool box drawers. This keeps my tools from rusting during the minter months, especially the mobile toolbox we take outside in the inclement weather.
Randy - RPM

Randy,

You can buy silica gel desiccant crystals in packets, about US$14.00 for forty packets.  Silica gel crystals are also available in cans and jars. These silica gel crystals are renewable.  Once the blue crystals turn pink or white, they can absorb no more moisture.  Simply bake them in an oven at 200*F (~94*C) for an hour or two, and the crystals will become blue again, good as new.
 
You can "recycle" them in an oven repeatedly, maybe forever.  
https://www.amazon.com/DRY-Premium-Indicating-Silica-Packets/dp/B01MQWW643/ref=sr_1_23_sspa?ie=UTF8&qid=1536534491&sr=8-23-spons&keywords=silica+gel+desiccant&psc=1

[racerrad8]

Red, I fixed the temp for you.

Yeah I know you can buy them, but since they are also included in most things we buy, I just collect them for use later.

Randy - RPM

[andyoutandabout]

Thanks to all for a healthy variety of ideas.
I'll study up on electrolysis, but I won't get to try it on the tank until I'm next in England. I figure two years.
Much thanks for the storage ideas as well.
I think my Mum can dangle some silica gel sachets in the tank for me. After all , it was her expert 80 year old eyes and ears that looked for oil leaks and listened to it run and ultimately buying it all before I got there.
Andy

[ryanschoebel]

I was also just going to link my post, thanks Randy. I ended up not coating the tank, but did use the electrolysis. Worked like a charm too

[andyoutandabout]

Silica gel bags made by Mum, installed by step dad, inspired by Randy

[FJmonkey]

I have no words for that....

[balky1]

Put the gel occasionally in the oven at 50-80 °C for cca. 2-5 hours (I even put it on 105 °C) to remove the accumulated water out if it since it has a certain capacity. It doesn't absorb the moisture forever.

[red]

Silica gel bags made by Mum, installed by step dad, inspired by Randy

andyoutandabout,

When you put silica gel into white bags like that, how do you tell when the stuff is saturated with water, and will not do any more good against moisture?  I know the blue silica gel turns white or pink when saturated, but you need one side of the container to be clear, to see that change of color.

[andyoutandabout]

Red,
I'm lucky to have the optional extra of 'mother monitor'.
With this system, an all-seeing, nurturing eye scans the tank surface for any additional corrosion and sends an e-mail to alert the bike owner if things look unsavory.

[Tuned forks]

Ooooooo, the all knowing, all seeing mother monitor. You've got a secret weapon.