A little help with MC tanks

[maxpower_hd]

I am working on a friends bike that has been sitting for several years. I drained the fuel, removed the carb to rebuild it etc. The stench of the gas was awful! I looked inside and the tanks are all rusty and gummy.

I plan to use POR 15 tank repair kit which I have used a couple of times before with good success. My issue is these tanks have an expensive, multi color paint job on there that I really need to protect. I was thinking I might just mask everything but I was wondering if there is a plastic film or something that might be better than just masking tape. The tanks I did in the past had so so paint that we weren't worried about or were going to get painted anyway so it wasn't much of a concern.

Any thoughts?

Thanks.

 

[rlitman]

I wonder if you could spray on plasti-dip and peel it off after you're done.
Of course, don't try this until you've proven it's safe. Not just the plasti-dip peeling, which I'm fairly confident in, but in the POR 15 not melting through the plasti-dip too.

 

[maxpower_hd]

Good point. I do have a spare tank I could try it on. I might give that a shot. Thanks.

 

[rlitman]

On second thought, wouldn't masking tape be less time consuming?
I think plasti-dip would make a good flexible mask (which is what I think you asked for), but is that what you really want?

 

[maxpower_hd]

What I need to do is protect the tank from the repair chemicals. Two of the ingredients are corrosive during the prep. Which I thought the plastic might be good for. The last ingredient is the sealer which is like a super durable paint. I need to keep it off the finish. I don't think the tape will offer the protection but it might be good enough if I'm careful and wipe anything off it right away.

 

[tatra]

See if por15 will eat thru Vaseline . Obviously test it on paint also. If both pass muster then slather tank up and go to work . See this used on industrial paint jobs for overspray. Use appropriate cleaner to remove Vaseline . Cheap and effective possibly. Dunno. Just a suggestion. Have used it myself for overspray on tires when painting rims . Pressure washed off .

 

[maxpower_hd]

That may also be an option. I do need to handle the tanks though so the Vaseline might be like trying to hug a greased pig. LOL

 

[sberry]

Is the tank leaking now?

 

[maxpower_hd]

The tank is not leaking. I am trying to clean the inside and seal it up to prevent rust from reaching the carb.

 

[ZRX61]

Reaching the carb? you mean it's still on the bike??? Surely the first thing to do is remove it. Then just fill it with vinegar for a day or 3.

 

[Todd.Brock]

I would think if low tack painters tape ruined the finish, you would have bigger problems. I would tape it and then wrap in plastic and tape off around filler neck and petcock Have at it cleaning and sealing.

 

[atch]

ya might wanna go over to the Jockey Journal and ask...

http://www.jockeyjournal.com

Although if it's still on the scoot I agree with just turning the petcock off and filling it with vinegar. Of course disconnect the fuel line from the carb(s). After a few days drain into a jug or bucket. Repeat if necessary.

 

[Arkansas COB]

If it was me I would just remove the tanks. Seal off the petcock and any vent openings.Put some small nuts and bolts inside with some soap and water and start sloshing in a circle. Turn at different angles and slosh. Do not shake or you might dent from inside. Rinse and have a look see. Repeat till most of the rust is gone. Since you have a good paint job i would not use the tank liner at this time. If you get enough rust out you will be just fine. Use an in-line glass filter so you can see if any rust builds back up.

As long as you keep the tanks full most of the time they shouldnt rust any worse than they are.

Save the tank linewr for another time like maybe when you need to repaint the tanks for some reason. I can say from experience that trying to do what you want to do without damaging the paint will be a PITA.

Good Luck
COB

 

[bwringer]

I've seen people successfully use duct tape in the areas around the openings to mask out POR15 (along with plastic over the rest). As long as the paint/clear is in good enough shape that it won't lift when you peel off the tape and clean it up, you should be fine.

I'd also run duct tape along the edges in case cleaning the gunk out of the tank uncovers any pinholes.

For cleaning the tank, use the products provided in the POR15 kit. Hard to tell exactly what you're dealing with just sitting here in front of my computer hundreds of miles away. Sometimes all you have to do is clean the gunk out and the tank is fine, sometimes it's so far gone the epoxy is the only thing keeping it together.

 

[ZRX61]

Although if it's still on the scoot I agree with just turning the petcock off and filling it with vinegar. Of course disconnect the fuel line from the carb(s). After a few days drain into a jug or bucket. Repeat if necessary.

It most likely has a filter inside the tank that will just clog up with all the **** inside the tank when he tries to drain it.

 

[ZRX61]

If it was me I would just remove the tanks. Seal off the petcock and any vent openings.Put some small nuts and bolts inside with some soap and water and start sloshing in a circle. Turn at different angles and slosh. Do not shake or you might dent from inside. Rinse and have a look see. Repeat till most of the rust is gone.

Why on earth go through all that effort when just filling it with vinegar & walking away works?

 

[yhprum]

Watch out if the taps are aluminum and you use vinegar; it might eat them away. There was another thread on GJ not too ago where they used Oxalic acid that left behind a corrosion resistant coating after treatment.

 

[softailgarage]

Did this once with a sporty tank. I used Muriatic acid with some nuts & bolts to clean the rust. I was careful and it didn't affect the paint.

 

[vtcat]

If you wait for it to leak the paint is ruined any way.
KBS is good,they are some people that left POR
Por15 is good,but Caswell is the best right now.
Kreen is the worst.

 

[Leaflessshadetree]

Look into masking film often used with air brushing. It's a somewhat flexible plastic/rubber with a light adhesive.
I'd get the inside cleaned out before deciding to line or not.

 

[maxpower_hd]

Reaching the carb? you mean it's still on the bike??? Surely the first thing to do is remove it. Then just fill it with vinegar for a day or 3.

No the carb is not on the bike. (Previous post). I need to permanently remove the rust and seal the tank to prevent rust from reaching the carb and clogging it in the future.

 

[maxpower_hd]

I would think if low tack painters tape ruined the finish, you would have bigger problems. I would tape it and then wrap in plastic and tape off around filler neck and petcock Have at it cleaning and sealing.

This sounds like a good idea. I am not worried about the tape ruining the paint. It is the chemicals and sealer in the repair kit I am worried about eating through the tape. But tape and then plastic should work.

Thanks

 

[maxpower_hd]

I've seen people successfully use duct tape in the areas around the openings to mask out POR15 (along with plastic over the rest). As long as the paint/clear is in good enough shape that it won't lift when you peel off the tape and clean it up, you should be fine.

I'd also run duct tape along the edges in case cleaning the gunk out of the tank uncovers any pinholes.

For cleaning the tank, use the products provided in the POR15 kit. Hard to tell exactly what you're dealing with just sitting here in front of my computer hundreds of miles away. Sometimes all you have to do is clean the gunk out and the tank is fine, sometimes it's so far gone the epoxy is the only thing keeping it together.

This was exactly my plan. The two I have done in the past needed the epoxy. One of them never got used and the other is still on the bike and working nicely after at least 5 years.

I have seen worse rust so I am hoping just the cleaning agent will be enough but I want the prep and epoxy in case it isn't. And I want to use all POR 15 rather than other materials to be sure it is all compatible and prevent any extra steps having to start over.

 

[maxpower_hd]

It most likely has a filter inside the tank that will just clog up with all the **** inside the tank when he tries to drain it.

This has already happened with the rust and gunk. I had to remove the petcock to finish draining the tank after siphoning.

 

[maxpower_hd]

Look into masking film often used with air brushing. It's a somewhat flexible plastic/rubber with a light adhesive.
I'd get the inside cleaned out before deciding to line or not.

This was along the lines of what I was thinking. There is a body shop near me I have used before. Maybe I will ask them about buying some masking film from them.

Thanks for all the suggestions guys. Sometimes it just helps to bounce stuff off of other people to come up with some ideas.

If I can find masking film I will use that. Then clean out the tanks and go from there. If I coat I will just leave the film on and prep and seal.

Thanks again.

 

[Kevin54]

What about taking a piece of luan plywood that is relatively thin, bore a hole through it that is just the size of the neck of the filler, then tape around that with duct tape. Any splash will get on the plywood.

 

[JimVonBaden]

Wow, lots of interesting advice here. So I will add some as well.

First, the tank has to be off the bike. No other way to do this.

Remove the tank, remove the petcock and check to see if it is salvageable. It may be ruined already. Remove the prefilter from the petcock and reinstall it. Fill the tank about 1/3 with vinegar, add some small nuts, a handful is enough. Slosh the vinegar around with the nuts in it. Let it sit a couple hours, then shake the tank, turning it in all directions. Drain the tank of all fluids. At this point you may be done, but likely not.

Refill the tank with vinegar all the way and let it sit 24 hours, leave the cap open. Drain out the tank and strain the vinegar if you wish to reuse it. Repeat until all rust is gone. Clean and dry it, but not for long. Flash rust will take hold in just 15 minutes. I use compressed air.

Now you are ready for your sealant. Cover the tank with Saran Wrap, 2 layers, including the filler. Remove the petcock and seal the hole(s). Push a funnel through the Saran Wrap into the filler and add your sealant. Follow the directions on application. Make sure you rotate the tank in every direction to get the sealant everywhere. Use two layers of Saran Wrap over the cap opening and close the cap over the Saran Wrap. Again, follow the application directions for the sealant.

When done, open the cap and remove the wrap from under it. Let the tank air dry, then remove the rest of the wrap and the petcock plug.

This should keep it clean and help you seal it.

 

[chrisBTSC]

I've used Rustol from Sudco on many occasions for a rusted tank and it works wonders. I would never use anything else.

 

[maxpower_hd]

What about taking a piece of luan plywood that is relatively thin, bore a hole through it that is just the size of the neck of the filler, then tape around that with duct tape. Any splash will get on the plywood.

That's an excellent idea. I might even be able to use some sort of rubber plug too! I'm starting to form a plan!

 

[maxpower_hd]

Well I already ordered the POR 15 kit which I have used before so I am committed to that product now. I might have tried the vinegar if I hadn't already ordered it but since it comes with a little different chemistry I plan to stick with their cleaner/neutralizer and metal prep as well so it will all be compatible with their system.

I may not have been clear initially but the tanks will absolutely be removed from the tank. I also plan on using nuts and maybe some small gravel to help with rust removal.

The pre filter at the moment is still sort of glued to the inside of the tank. I might try to soak and salvage the expensive chrome unit but will replace if need be.

 

[bwringer]

That's an excellent idea. I might even be able to use some sort of rubber plug too! I'm starting to form a plan!

Depends on the bike, but quite often you can find an expanding rubber plumbing plug that will work to seal the gas cap opening.

 

[maxpower_hd]

So thanks again for all the ideas. I now have at least a pretty good plan going forward.

Just for a mental picture this is a custom built Softail style motorcycle with two separate stretch tanks.

Tentative Plan:

1. Remove tanks. (already half way there)

2. Obtain or make appropriate plug materials. Maybe expandable rubber, maybe make my own from plastic sheet or luan to tape/seal over filler neck and petcock hole. (hehehe....he said pet AND ****)

3. Wash exterior of tanks with mild soap and water and dry.

4. Mask with either good quality 3M masking film if obtainable or mask with good quality masking tape, then cover tape with plastic.

5. Plug petcock hole (hehehe again) and seal

6. Add nuts and maybe some small gravel peices

7. Add tank cleaner and soak/rotate according to directions

8. Drain, remove nuts and gravel and dry according directions using compressed air or maybe even nitrogen. (might be able to get if from work)

9. Inspect interior and decide if I need to seal. (my current hypothesis is I will need to)

11. Add metal prep solution, seal/rotate etc per instructions (I didn't skip 10. That was a drink break)

12. Drain, dry and inspect as above

13. Add sealer, seal/rotate again per instructions

14. Remove plugs and let air dry (I think it said 24 hrs but I will find out when I get the kit.)

I think that about covers the tanks. The rest should be repairs associated with the extended sitting. Like new fuel line, the petcock itself, rebuild and clean the carb, etc.

I'll let you know how I made out.

 

[Aimsmall]

You could try a liquid mask, brush it on and dries to a thin rubber film, easy to peel off and shouldn't damage the paint. If the rust is really bad you could cut open the bottom of the tank, sand blast the inside then weld the piece you cut back in too.

 

[maxpower_hd]

I don't think cutting the tank is going to be in the plan. At least I hope not. Here is a couple of pics of the tank. I think I would rather get new tanks at that point.

 

[LS6 Tommy]

I thought this was going to be about acetylene...

Tommy

 

[maxpower_hd]

A little trivia....the MC tanks were originally used to run gas lights on motorcycles and the B tanks did the same thing for buses. Thus the letter designations.

 

[maxpower_hd]

Someone yesterday just suggested that a radiator shop might be able to flush and clean the tanks and coat it with some red stuff. Anyone know what that might be? Or should I just stick with plan A you think?

I went to the hardware store and couldn't find exactly what I wanted for masking but ended up with Frogtape for delicate surfaces with an advertise 60 day lift off period. And I also found some clear poly adhesive floor protector film. I figured I would mask with the tape to protect the paint and then go over that with the plastic to protect both.

 

[yhprum]

Here is the redstuff: http://damonq.com/red-kote.html
Its supposed to be impervious to modern fuels. I have somee for my next project. I have been soaking a painted popsicle stick in a sealed jar of gasoline for several months, its still sticking and cured.
Before trying the radiator shop route, I would still try corrosion removal beforehand with one of the acids listed with paint protection.