Topic: Stubborn Tank Rust...

[farinhite]

So I tried using Evaporust in my tank, and it seems that I've caused quite a bit of flash rusting, even after dumping Marvel Miricle oil in the tank afterwards. I'm afraid that I'm going to cause further rust in the tank. 

At this point, I'm not sure if should I give it a go with Esprit, or take it to someone who knows what their doing?

Does anyone know of someone in the Los Angeles area that can remove the rust from the tank, while preserving the original pain job?

[dave500]

50/50 mollases and water,fill the tank with it and let it sit for a week or two,rinse out well,it wont hurt your paint.

[lucky]

50/50 mollases and water,fill the tank with it and let it sit for a week or two,rinse out well,it wont hurt your paint.

WOW ,I would never do that. What if you do not get it all out?

Anyway a light coat of rust is OK if you line the tank with CASWELLS tank liner.
Add white epoxy colorant to the Caswells liner .You can get it at TAP plastics in a small 2 oz. jar already mixed. Caswell said it is ok to do that.

[Lostboy Steve]

DIY electrolytic rust removal. BEST WAY!

[2wheels]

I just did a rusty tank.  Filled it with vinegar from the grocery store.
Left it in for 2 days,  I had some nuts and washers inside and shook it often.

Next, and I should say this step was done in 10 minutes so you have to have everything ready.
Dumped the vinegar out, not on the lawn as it kills grass.
Add water with some baking soda to rinse and neutralize the acid.
Dump water and blow out with compressed air.
Add a cup of alcohol (methyl hydrate is what I used)  Swish around.  Dump and blow dry.
Another cup of alcohol.  Swish around and blow dry.  This gets all the water out.
Add a cup of 2 stroke oil into the  tank.  Swish around.  You are done.

[Esprit Performance]

farinhite: I just noticed your comments concerning flash rust after I posted about varnish removal. An easy solution to the flash rust is to add a small amount of drygas and gasoline, slosh it, dump it out then slosh it with Marvel Mystery oil. Also choosing a dry, low humidity day will reduce flash rusting. This method will not fail to prevent flash rust.

Is there any possibility that you are seeing left over varnish in the tank that has covered some light rust? How long did the tank sit before using the MM oil? It is very unusual for a tank to develop flash rust if the clean, bare metal is sloshed immediately afterwards with MM oil.

I'm not sure there are any less hazardous or safer ways other than the chelant based rust removers, regardless of brand. The last thing you want is someone using phosphoric acid that will remove fresh metal with the rust. In response to twistedengineering: With electrolytic rust removal, metal is also sacrificed and all badges, chrome, etc would have to be removed.  With chelant type fluids, there is no worry about paint, badging, chrome, etc. An entire tank could be soaked.  The advantage with Esprit is that it costs much less, is pure chelant chemistry and will not remove metal, only the rust. The Evapo-Rust contains a sulphur based additive that precipitates out of solution. It is possible this could be what you are seeing as fash rust, but I doubt it would show up after treatment and rinsing.

I am still searching for a definitive way to remove stubborn varnish prior to rust removal as mentioned in my previous post reply.

Thank you all in advance for any suggestions, feedback and corrections.

2wheels: It is good that you had a positive experience using a non hazardous method and you have posted precicely what I did about flash rust. It is a great method. I must say though for those who don't want to take a longer time or use hardware, the chelant rust remover is ideal in terms of speed and ease since you don't have to shake anything inside or neutralize afterwards. Excellent suggestions though.
 

[madScientist]

I use CLR. Fill the tank as best you can. Turn it to a different side every 24 hours or so. In about 4 days you're done! I did a REALLY rusted up GL1000 tank this way and it turned out great! When i'm not on one of my 750's I'm on the 1000.

[dave500]

50/50 mollases and water,fill the tank with it and let it sit for a week or two,rinse out well,it wont hurt your paint.

WOW ,I would never do that. What if you do not get it all out?

Anyway a light coat of rust is OK if you line the tank with CASWELLS tank liner.
Add white epoxy colorant to the Caswells liner .You can get it at TAP plastics in a small 2 oz. jar already mixed. Caswell said it is ok to do that.

you probably wouldnt get it all out lucky,thats why you would never do that.

[Hot500]

+1 on the Mollases.   Absolute miracle cure for rust. Eats rust will not harm paint or metal.

It doesn't even have to be 50/50. 80 parts water 20 mollases will work fine. Maybe take a little longer.

If your not sure about the tank, find a rusty peice of junk and drop it in a bucket of mollases/water for a couple weeks.

You'll be amazed at how it comes out.

I've done a tank on my SL350 and CB550 with this method. Brilliant.

[farinhite]

+1 on the Mollases.   Absolute miracle cure for rust. Eats rust will not harm paint or metal.

It doesn't even have to be 50/50. 80 parts water 20 mollases will work fine. Maybe take a little longer.

If your not sure about the tank, find a rusty peice of junk and drop it in a bucket of mollases/water for a couple weeks.

You'll be amazed at how it comes out.

I've done a tank on my SL350 and CB550 with this method. Brilliant.

Hey exactly what molasses did you use? How long did you set it?

[Bailgang]

Electrolysis, then vinegar and now molasses. You guys continue to amaze me on all the DIY ideas you come up with.

[Hot500]

+1 on the Mollases.   Absolute miracle cure for rust. Eats rust will not harm paint or metal.

It doesn't even have to be 50/50. 80 parts water 20 mollases will work fine. Maybe take a little longer.

If your not sure about the tank, find a rusty peice of junk and drop it in a bucket of mollases/water for a couple weeks.

You'll be amazed at how it comes out.

I've done a tank on my SL350 and CB550 with this method. Brilliant.

Hey exactly what molasses did you use? How long did you set it?

In Australia we use a lot of molasses for animal feed, so just get it from the produce store. Mix it up well with warm water and then pour into tank to completely full. Depending on condition of the tank or whatever part your derusting at least 2 weeks.

My SL350 tank was pretty bad, so I gave it 3 weeks.

But you must be ready to treat your tank as soon as you empty the mix, otherwise rust takes up again.

Oh, by the way, the mix can be used over and again. Works just as well as the first time.

[dave500]

shake it up every other day,,the smell makes you want to crack a beer open,stuff will flash rust straight away so be ready with your primer etc,old bolts etc in a bucket of the stuff come out like new,i use a metal etch type prep on tanks like the stuff you get in the por kit,leaves a kind off coating you can paint over.


remove any aluminium and alloys though like your fuel tap,,i use those tapered rubber offcuts that come from a truck puncture repair plug for fuel tap bolt holes,masking tape works aswell.

[killersoundz]

fill it with small gravel pebbles, like aquarium gravel. wrap it in a big blanket, put it in your dryer and let it tumble around for a while. works great polishes it right up

[BeSeeingYou]

Is Evapo Rust phosphoric acid?  Never have used it but I have used Prep and Etch a phosphoric acid.  You don't rinse this out but let it dry in the tank and it leaves a protective coating.  Other acids need to be neutralized and then rinsed out and the tank dried quickly.  Does not seem to hurt the paint if you wipe it off right away.

[nccb]

I used 2 gallons of white vinegar and let it sit for 2 days but made sure to shake it vigorously every now and then.  When I dumped it it was crazy the crap that came out then sprayed it thoroughly with my water hose and stuck my wife's blow drier to it till it was dry inside.  I haven't had any flash rust but it did leave a little rust towards the back and bottom, doesn't look like a big deal though.

[Kickit85]

Go to youtube and look up "rusty gas tank cheap fix." This guy has a pretty ingenious method.
Then slosh around some diluted muratic acid and finish with a coat of por-15. It works miracles.

[farinhite]

Go to youtube and look up "rusty gas tank cheap fix." This guy has a pretty ingenious method.
Then slosh around some diluted muratic acid and finish with a coat of por-15. It works miracles.

How to Clean a Rusty Gas Tank

Hahah riiiiiighht. I'll go ahead and get a tractor then?

[Kickit85]

The one I was looking at was wrapping the tank in towels or blankets and tossing it in the drier on a no heat cycle. Although if I think the tractor method is much cooler...

[jstfkndi]

I did the tank in the dryer method with the large gravel to get the big stuff. I have all that out, but now I need to make it shiny inside. I have some very high concentration (82%) phosphoric acid, but am curious as to what percentage I should have it down to and should I flip it every day for how many days? I have read some stuff, but since I am making my own solution I haven't seen any info on the mix. I can do the math, I just don't want to hurt my tank. I am not worried about the paint as I plan on having it repainted anyway, but will do my best to keep it clean. And with this acid treatment, is it not necessary to throw some two stroke oil in to prevent the flash rusting? Don't want to thread jack, but this seems like the place to ask.

[farinhite]

So after trying Evaporust, with not great results, I went ahead and got 3 gallons of white vinegar and some screws and threw then in the tank to get some of the left over varnish.

It worked extremely well.

I would highly recommend this method before you move to any sort of acid dip process.

I neutralized with baking soda. Rinsed, then used a small bottle of Heet to get the water out. Stuck a blow drier in there for a couple mins, and then dumped a few cups of 2 stroke oil into the tank and filled the tank with gas. No flash rusting yet.

I feel like this is the cheapest, easiest first time around solution to get rid of rust. Perhaps later I'll take it to a real repair shop, have it sand blasted and coated, but for now, this is a heck of a lot cheaper, and paired with a couple fuel filters I think it should be fine for a while.

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