Hi,

 

I have cleaned a rusted tank for my Honda steed following youtube instructions with 15% hyperchlorid acid, using a houshold cleaner. It worked well and stripped the surface perfectly blank in under an hour.

Once stripped and rinsed, I neutralized the remaining acid with a baking soda water solution as instructed since the remaining acid on the surface would otherwise make it rusty again within minutes.

 

But it happened anyway, Flashrust, within 10 minutes, surface all brown, rusty and ugly again. What did I do wrong? Is it a question about quantities?

Or is the baking soda also corroding the metal when overdosed? Anyone knows, please advise.

 

An alternative option would be using a tank cleaner kit such as from Kreem, POR or others, are they available anywhere in Thailand?

Unfortunately those chemicals aren't shipped to Thailand,

https://www.amazon.com/Kreem-Products-Fuel-Liner-Combo-Pak/dp/B001J0DHZK

 

Thanks for any advice!

 

Phil

I used an old coat hanger to remove the rust by electrolysis instead of  using acid as there is no chance of the metal being eaten away

its tricky to insulate the two metals from touching inside the tank so I used an old pair of flipflops cut up to make insulators

the electrolyte was baking soda

 

 

 

You could try electroplating  I had some success using the same PC 12V power supply and a Zinc rod from the builders merchant as for rust removal but reverse the polarity.

 

 

 

 

 

 

Yes thats the kitchen sink !!!

 

You can also try de rust and then immediately  pouring in a quantity  of 2 stroke "autolube"  put on the  petrol cap and slosh it about  but the rust will come back as soon as you let the air get to it,  if you keep the tank full of petrol it will also slow the rust a lot.

 

Hi, I normally use white vinegar and leave it overnight, then mix in some vitamin C, and give it another 1 hour before cleaning out. I have been using a phenolic epoxy thick two part paint on the tank internals, once prepared. 

From the photos that tank looked quite heavily corroded, so there is a risk of pinholes forming as a result of the thinning metal.

 

It is a good idea to use gravel in the liquid mixture and then shake the mixture around to remove the rust and expose any heavily corroded areas.

 

Lightly planishing the underside of the tank too will also expose any bad areas, especially around welded joints where rust is likely to be heaviest.