Author Topic: Mavel Mystery Oil Vs tank Lining (Read 7414 times)

Ace Blackwell · « **on:** January 16, 2016, 11:03:13 AM »

All,

I'm getting back to my tank restoration after the holidays. I've read lots of approaches to removing rust. My approach is a combination like most others. However, I read where some uses the Mystery Oil as a tank coating and others POR-15 tank liner. Is there a condition where one would be used over the other? Or is one used until the other could be used? Or is it just personal preference?

Thanks
Ace

seanbarney41 · « **Reply #1 on:** January 16, 2016, 02:08:15 PM »

after you are done removing rust...and there are no leaks, there is absolutely no reason to use a liner. I f you have pinholes, then you may need a liner. Personally, I will do everything I can possibly do to avoid using tank liner, as I believe every liner available is a failure waiting to happen. Even if a liner holds up for 5 years, when it fails you have a huge problem to fix.

Ace Blackwell · « **Reply #2 on:** January 16, 2016, 03:14:05 PM »

Thanks for the advice. I didn't realize the liners were not permanent. Besides I don't have pin holes and I can always go to the liner later if I choose. I was just thinking long term about rust.

Ace

seanbarney41 · « **Reply #3 on:** January 16, 2016, 03:24:24 PM »

Liners are "supposed" to be permanent. The problem is 10 percent ethanol gas. Your tank will not rust once in regular use and cared for properly.

mystic_1 · « **Reply #4 on:** January 16, 2016, 03:27:53 PM »

Not to mention that tank liners can be tricky to apply well. If you don't get the tank completely clean inside, or if you don't apply the liner properly, it won't adhere well and will eventually start peeling off inside.

They're best avoided, I agree.

Quote from: seanbarney41 on January 16, 2016, 03:24:24 PM

Your tank will not rust once in regular use and cared for properly.

Agreed. In particular, try to keep the tank mostly full, as rust tends to form in the parts of the tank exposed to air.

mystic_1

carnivorous chicken · « **Reply #5 on:** January 16, 2016, 03:30:22 PM »

Pinholes are the main reason as stated. That being said, I have a tank that I lined with POR-15 10+ years ago and it's still fine. If you do it right, it won't fail, in my experience. Kreem is terrible, and I have a tank with Redkote in it that's been going strong for 6+ years. If you're repainting, you might want to consider lining as well -- if a pinhole leak develops, you're going to have to line it and repaint it.

calj737 · « **Reply #6 on:** January 16, 2016, 05:36:44 PM »

To answer your original question, Marvel is used to prevent flash rusting or "fogging" a tank after de-rusting. POR-15 is an applied epoxy liner. Many like liners, many don't. If you don't need a liner, I'd shy away from it until such time as you determine you need a liner.

But if you ever do need a liner, Caswell is the bomb and ethanol doesn't bother it one lick.

przjohn · « **Reply #7 on:** January 16, 2016, 05:51:08 PM »

I don't see how Marvel could be considered a tank liner. I have had very good luck with The Caswell Kit and have been lining all my resto tanks for the past 10 years. When you have a good investment in paint it makes sense to line the tank on old bikes IMO. If you follow the Caswell directions you will have no problems.

mystic_1 · « **Reply #8 on:** January 16, 2016, 07:36:26 PM »

Marvel Mystery Oil is not a tank lining.

It's an oil.

Like any other oil, it leaves a film on surfaces which help inhibit rust, but like any other oil it'll get washed away quickly by gasoline.

mystic_1

Don R · « **Reply #9 on:** January 16, 2016, 09:19:40 PM »

Some guys are using a little synthetic 2 stroke oil mixed in to help protect the tank and original type exhausts too. It burns clean and doesn't smoke when used lightly. Avoid storing it with gasohol if you can buy straight gas. Race gas or Avaition gas stores well too.
The marvel may also help ward off rust, in a high performance engine, burning oil can cause detonation. Not likely in our case if everything is in good working order. And of course some guys would never do either in any case.

dhall57 · « **Reply #10 on:** January 17, 2016, 01:13:12 AM »

Don't know about gas tanks but MMO works great on freeing up stuck engines

Powderman · « **Reply #11 on:** January 17, 2016, 08:30:48 AM »

The Marvel Mystery Oil is used to line the tank when it is empty and put in storage for a period to keep the rust from starting. I see no other benefit to it if there is gas sloshing around in the tank from use, the oil will just wash off.

BobbyR · « **Reply #12 on:** January 17, 2016, 11:15:22 AM »

If you do a search. you will find many threads on tank cleaning and lining, if necessary. It depends on how much rust there is. Some people have had good luck with Vinegar which is cheap and safe. Toilet bowl cleaner is good for some conditions. Electrolysis is used for some tanks. It is all there fro you to make an informed decision.

Coatings mentioned can be a problem, even if applied properly. I am not blowing you off reccomending a search. There are step by step tutorials on this site.

bochnak · « **Reply #13 on:** January 19, 2016, 07:29:55 AM »

I use vinegar or evaporust to remove as much rust as possible. If I have to coat the tank, I use Caswell epoxy.

I have a couple of videos on the process here:

https://www.howtomotorcyclerepair.com/restoring-a-rusty-motorcycle-tank/

-Matt

flybox1 · « **Reply #14 on:** January 19, 2016, 07:41:18 AM »

Quote from: Powderman on January 17, 2016, 08:30:48 AM

The Marvel Mystery Oil is used to line the tank when it is empty and put in storage for a period to keep the rust from starting. I see no other benefit to it if there is gas sloshing around in the tank from use, the oil will just wash off.

+1
Only for storing a (good on inside) empty tank.

Lostboy Steve · « **Reply #15 on:** January 20, 2016, 09:04:17 AM »

Quote from: bochnak on January 19, 2016, 07:29:55 AM

I use vinegar or evaporust to remove as much rust as possible. If I have to coat the tank, I use Caswell epoxy.

I have a couple of videos on the process here:

https://www.howtomotorcyclerepair.com/restoring-a-rusty-motorcycle-tank/

-Matt

I am doing my tank with the caswell even though I am usually a loyal por15 guy. You like it huh?

bochnak · « **Reply #16 on:** January 20, 2016, 09:15:45 AM »

I have done about 6 tanks in the past few years with no issues. I have never tried POR, though.

I have done both clear and black, which actually turns out to be translucent black. I prefer the black kit as it hides all the imperfections and you can see the coverage easier over the clear kit.

Ace Blackwell · « **Reply #17 on:** March 06, 2016, 08:27:56 AM »

All

Ok, was able to get the tank rust soaked and found that i have two small pin holes on the flat of the bottom. I am starting to get mixed feelings about epoxy lining. Given that the holes are in an unseen area of the tank, would it be easier / wiser to apply epoxy directly to the holes from the outside. Or is there enough confident in the POR / Caswell process to go that route. I like the idea of coating the tank permanently, not so fond of coating the inside of my carbs/engine permanently .

Thanks
Ace

calj737 · « **Reply #18 on:** March 06, 2016, 08:34:40 AM »

If your tank is clean inside, etch it with Prep and Etch. Dry overnight. Pour 1/2 of mixed Caswell in and gently rock the tank back forth covering the floor plates and up the side seams. Let sit 6-8 hours. Pour other 1/2 in and invert tank to get underside of top, and side panels. Cure overnight. Done. Permanent. Ride on!

mystic_1 · « **Reply #19 on:** March 06, 2016, 09:19:01 AM »

Are you sure you only have two pinholes?

Unless the holes are from impact damage or some other mechanical cause, then the holes came from rust, and if it rusted THERE then it probably rusted elsewhere also, maybe not enough to go all the way through, but my point is: how thin is the metal in that area now?

If you're pretty confident that there's really only two holes and the metal is sound, why not weld them up? That's a trivial job with a welder, and no worries about crapping up your fuel system. (naturally drain rinse and purge the tank before welding)

If the metal is sound and you can't get it welded up, then after making sure the metal isn't dangerously thin in that area I would apply a small amount of standard two-part epoxy from the outside to close the holes, AND then line it with your liner of choice. The epoxy from the outside is just to make the internal liner lay down nicely, if just used alone without an internal liner, it would be destined to fail.

All in all though my personal preference is not to line tanks, so get it welded up if possible. If they're literally pinholes, then you're talking about 5 seconds of actual welding trigger time, with time for prep and cleanup on either side.

BTW if it were me, before I did any lining, I'd also take the tank, seal up the fill hole, run a small amount of air pressure into the petcock hole, and immerse the tank in water. Don't rely on visual inspection if you're dealing with pinholes, a bubble test will reveal them for sure. Mark them by circling with a scribe, then dry off the tank and plug them by welding or with epoxy as per above. Then you can repeat the test until you're 100% sure the tank is airtight. THEN worry about the internal liner.

mystic_1

Ace Blackwell · « **Reply #20 on:** March 06, 2016, 09:36:31 AM »

Thx, you mean like concrete etch and prep? Or is there an epoxy etch and prep?

mystic_1 · « **Reply #21 on:** March 06, 2016, 09:39:19 AM »

Tank liner kits typically come with a mild acid solution to clean out an remaining residue and etch the metal slightly in preparation for the coating.

Get a kit so that you're sure all the component chemicals are compatible with each other, and follow the directions carefully. As said upthread, this is easy to screw up and there are plenty of stories about failed tank linings out there on the web.

mystic_1

calj737 · « **Reply #22 on:** March 06, 2016, 10:08:10 AM »

Quote from: Ace Blackwell on March 06, 2016, 09:36:31 AM

Thx, you mean like concrete etch and prep? Or is there an epoxy etch and prep?

Just like Concrete Prep 'n Etch. You can use the same product on metal to remove rust, on metal as pre-treatment for paint, or on concrete.

If the floor plates are rusted and thinned as ideated, the Caswell will more than strengthen that area. And the Caswell may bleed through the pinholes, but not likely. Its pretty thick and sets up quickly too. If it does seep through, you'll be assured of having the hole filled anyway. Scrape it smooth or back the hole from the outside with blue tape prior to lining.

grcamna2 · « **Reply #23 on:** March 06, 2016, 10:36:05 AM »

Quote from: carnivorous chicken on January 16, 2016, 03:30:22 PM

Pinholes are the main reason as stated. That being said, I have a tank that I lined with POR-15 10+ years ago and it's still fine. If you do it right, it won't fail, in my experience. Kreem is terrible, and I have a tank with Redkote in it that's been going strong for 6+ years. If you're repainting, you might want to consider lining as well -- if a pinhole leak develops, you're going to have to line it and repaint it.

przjohn · « **Reply #24 on:** March 06, 2016, 10:43:52 AM »

If you have pin holes you have a tank that could definitely benefit from a liner as odds are, there are many more areas ready to pop through. The Caswell kit is a 2 part kit and the POR15 is a single part kit that goes on thinner and is more like paint. You have absolutely no reason to fear applying The Caswell liner. I have done many tanks both metal and fiberglass with no failures. If you follow the simple instructions you will have a leak free tank that lasts.

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Author Topic: Mavel Mystery Oil Vs tank Lining (Read 7414 times)