Q re: cleaning and lining 2001 carbed Monster tank

[NeilF]

TL;DR summary: How would you clean/line rusty tank for carbureted 2001 M750?

Detail:

I am trying to revive a tank with a rusty interior on my carbureted 2001 M750. I plan to use the POR 15 motorcycle kit to clean and line.

(By the way, this is my first experience with any work on my own bike, but I'm not a complete stranger to basic auto repairs)

Initially, the gas cap was rusted shut. I had to drill a hole in the outer gas cap surface to access the inner holding screw and remove the entire assembly.

This is also the style of tank with drain (overflow?) lines inside and fuel filter outside. As far as I can tell, there is no way to remove the internal lines.

To add insult to injury, I can't figure out how to remove the fuel-level sensor from the bottom of the tank. I've already inadvertently snapped the wires off the bottom (from aggressive shaking with water to rinse the inside), but the assembly remains firmly intact. If it unscrews (I'm told it does) I've not figured out how to do it.

Since I am more concerned with a clean tank than a functioning fuel sensor, I am thinking of just starting the POR 15 cleaning/lining process without removing the fuel sensor (I know this may kill low fuel light, but I can live with that...I think). But with the internal drain lines, I am concerned that I may ruin the whole tank if I just start the cleaning/lining process as is (and merely plug the existing holes while treating).

Might anyone have perspective on this variation of tank, whether I must do more to remove internal components before I clean (if so, how?), and/or whether I can proceed with POR 15 process without worrying about totally destroying the tank?

Any thoughts/suggestions would be greatly appreciated. Thanks!

[ducpainter]

I have a little experience with this.

First...Remove the sender. Loosen the large nut and pull it out. If you leave it in there will inevitably be rinse water trapped that will ruin your job.

Second...the acid for the POR works quite well, but with heavy scale it will take forever to remove it, and you'll be rolling the tank for days. Buy yourself a 5 gallon Evaporust kit. http://www.evapo-rust.com/  Plug all the holes and fill it to the top and let it sit until the rust is gone. Then do the POR process like you were just starting. Follow the directions exactly...right down to the temperature of your work area.

The internal steel lines are not removable. Make sure they are clear...not plugged.

I strongly recommend a blow dryer or heat gun to dry the tank. Use it on low. I've burned the paint on tanks before.

Depending on how rusty the tank is, it is possible it will be porous after the evaporust/POR treatment. If that happens all is not lost. We can deal with that when it happens.

[NeilF]

Thanks DP, this is great help.

Forgive me for potentially silly question. Once fuel sensor large nut is off (it is), if fuel sensor won't pull out (it won't), are there any special tricks? Or should I just brute force it out using whatever it takes?

[ducpainter]

I'd rather use the term finesse. It will come out. You'll likely need to replace it, or the oring, at least.

A screw driver between the flange and the threaded bung...a pair of channel locks on the flange.

It will come out.

[clubhousemotorsports]

If you are in the US I would not use POR any more.

Most POR I have seen is failing , even it should be done right. I would look at the caswell tank kits, they may not last forever but so far Kreem,redcote,POR-15 have all failed.

Other than that , painter is right on the money.

[ducpainter]

If you are in the US I would not use POR any more.

Most POR I have seen is failing , even it should be done right. I would look at the caswell tank kits, they may not last forever but so far Kreem,redcote,POR-15 have all failed.

Other than that , painter is right on the money.

You've seen some fail, but most, really? I've had a few fail, and I honestly don't know why, but with the number of tanks I coated over the years, I'd expect more complaints if the POR truly sucked.

I'm not a real fan of the Caswell product, because as packaged it's a real pain to work with. It isn't bad if reduced, but because it's an epoxy you have to be careful about compatibility with rust removal products. Caswell says leave the rust in there. I say bullshit.

[Howie]

Just a thought.  Could POR15 have changed chemically due to whatever environmental code might exist? 

[koko64]

Always a possibilty. I have seen Kreeme let go after a few years and clag carbs and filters. Maybe new fuel additives contribute, I'm not sure.

[Truckedup]

Always a possibilty. I have seen Kreeme let go after a few years and clag carbs and filters. Maybe new fuel additives contribute, I'm not sure.

  Any sealer can fail....it's an odds job, the odds are if you do it correctly it will be fine...But a percentage will fail because sealing a tank is a blind job you can never be 100 percent sure the entire interior is prepped properly....And a failure of the sealer is a real mess....I say only use sealer as a last resort.....

[clubhousemotorsports]

It has become rare for me to see a tank come into the shop with POR-15 in the tank that is NOT bubbling in spots. There was no problem for  many many years but about 2-3 years ago something changed and now it is common for me to give the news to customers that the tank they had sealed is now a big question mark.

Yes Truckedup the process needs to be done correctly for it to work, Given many of these obs I am seeing were done professionally by different  pro's  you would think I would see less problems if it was simply someone did not do a good job.

No one wants to re-coat tanks after they have been done  because it can take 2x the time to get the old coating out before a new coating goes in so many Pro's wont touch them. I certainly get that and it forces owners to start doing the work themselves, as a repair shop I have no interest in doing a job I cannot be sure will last. 

Painter I get you do not like the caswell process and tomorrow I may start seeing caswell failures, but as of today 12/2016 they are the only process I have seen that does not fail with our fuel. I would simply like to see our old fuel back and then 90% of these problems go away. Not going to happen.

[ducpainter]

<snip>

Painter I get you do not like the caswell process and tomorrow I may start seeing caswell failures, but as of today 12/2016 they are the only process I have seen that does not fail with our fuel. I would simply like to see our old fuel back and then 90% of these problems go away. Not going to happen.

I'm not saying that the Caswell will fail chemically, or bubble off the surface due to ethanol damage. If you simply add a layer of epoxy on one side of the cancer...it doesn't stop the cancer. It just stops the rust from clogging the filter. Is it better? I guess if your bike keeps running it is. My problem is that it isn't a real solution. It's just a band aid, and eventually you'll just have an epoxy bladder.

The fuel will get worse before it gets better.

[ducatiz]

Caswell or Bill Hirsch.

Bill Hirsch makes a kit for motorcycle tanks -- has the rust remover, etch. and coating all in one kit.

http://www.hirschauto.com/MOTOR-CYCLE-TANK-REPAIR-KIT/productinfo/CRK-01/

I use Bill Hirsch on all the metal tanks I refurb.  Never had a failure.  Follow the directions PRECISELY.  After you do the etch, the inside of the tank will be 100% virgin metal -- dry it well.  Try to do the work in a low humidity environment -- a small hair dryer helps a lot to blow out the moisture and prep it.

[Truckedup]

  Around here non ethanol fuel is readily available.....I work on vintage British bikes for a few guys..They are old and the fuel tanks get rusty inside...If the tank is solid I clean it by shaking it with a hand full of dry screws inside. Then remove the screws and use phosphoric acid.No sealer...For the most part the tank will stay clean enough inside as not to be a problem. Sometimes the tank flat bottom needs to be cut out and new metal welded in...Due to the shape of newer bike tanks it's not easy to do this..
I was given an old Triumph bike to repair and one problem was a Creme sealer failure...I cut a hole in the tank so I could be sure all the sealer was gone...Once removed I saw the tank interior was not rusty...So the sealer may have failed because of fuel or a bad prep job...
  If a tank leaks from crack or failed weld I can easily repair that after using proper precautions to purge the tank of fumes...But if the tank has sealer inside, all the sealer needs to be removed first...

[ducpainter]

Caswell or Bill Hirsch.

Bill Hirsch makes a kit for motorcycle tanks -- has the rust remover, etch. and coating all in one kit.

http://www.hirschauto.com/MOTOR-CYCLE-TANK-REPAIR-KIT/productinfo/CRK-01/

I use Bill Hirsch on all the metal tanks I refurb.  Never had a failure.  Follow the directions PRECISELY.  After you do the etch, the inside of the tank will be 100% virgin metal -- dry it well.  Try to do the work in a low humidity environment -- a small hair dryer helps a lot to blow out the moisture and prep it.

When was the last time you did one with the Hirsch product 'Tiz?

[Speeddog]

TL;DR summary: How would you clean/line rusty tank for carbureted 2001 M750?

~~~SNIP~~~

I'd send it to these guys:

http://www.gastanklining.com/