21 replies to this topic

[MrBounce]

Read my rebuild thread - I have done the van tank on my Midas using the Frost kit. It is brilliant.

[Captain Mainwaring]

If the plan is to line the tank with a product like the POR kit, DO use the nut, bolts, rocks, etc.  Your goal is to get all the rust and deposits out so the liner will bond well to the inside of the tank. 

 

However, I do agree that if you are NOT going to line the tank, getting the rust out is likely to just open up pin holes (and larger holes) that are currently plugged with rust.  So... nuts and bolts if lining... don't do any aggressive cleaning at all if you are not going to line the tank.

 

 

Mini tanks aren't rare - I wonder if it's worth the effort to try and recover one.

 

You need chemi clean to get rid of the rust, even if it does leave pinholes - that won't matter to slosh tank sealant, if you don't get rid of the rust and then passivate the steel you are wasting your time, you'll get rust form under the sealant skin.

 

I've just pickled and passivated my triumph bonnie tank, but it was only light surface rust. The key is to get very step completed as quickly as possible so that corrosion doesn't start back up again.

[dklawson]

Passivation?  That term does apply to the use of phosphoric acid on mild steel but it is generally a term I am more familiar with when discussing nitric acid surface treatment of stainless steel.  In addition to removing the rust, with the POR coatings the acid performs an important etching function to give the steel surface a "tooth" the coating can lock into.

 

Regardless, we are not saying anything different.  We are both saying that you need to get rid of the rust prior to applying the coating.  As I mentioned previously the POR kits come with a strong caustic cleaner which is then followed by a phosphoric acid soak/wash.  My comment on the pin holes was to point out that the acid wash can open pin holes in a tank that might not currently be leaking because they are plugged with rust.  Once a tank is acid washed you may find you must line it to plug those pin holes. 

 

I also mentioned in a previous post in this thread that being in the U.K. replacement (new or used) tanks remain an option for you.  Mini tanks are available here but they are not readily availbe.  I am not able to pop down to the junk yard or call a friend and get one.  With shipping charges being what they are... a tank lining kit is more economical to me in the U.S.  I don't recommend lining when a new or better tank is available.

[SMP]

If your mini is not used much then even with a new tank are you going to end up with rust again unless you keep the tank full of petrol. Therefore is it not a good idea to line the tank anyway

[Captain Mainwaring]

Maybe not - I had an old CBR years back that had been sealed and the coating had come away and blocked the fuel outlet periodicall - it was a pig to diagnose - sometimes it would run for miles with no grief then stop ten times in a mile.

 

If it ain't broke it may not be a good idea to fix it....

[Carlos W]

Make sure the sealant is safe with fuel with ever increasing amounts of ethanol in it

[dklawson]

The POR coatings are compatible with fuels containing ethanol.  

 

For those unfamiliar with the POR coating and other POR products, the links below may prove informative.

 

The basic fuel tank coating...

http://www.por15.com...ealer_p_64.html

 

and the complete motorcycle tank lining kit which works well for a Mini...

http://www.por15.com...Kit-_p_106.html

 

Note that the kit comes with two prep products.  The "cleaner degreaser" is what they used to sell as "Marine Clean" and the "metal prep" is what they used to sell as "Metal Ready".  From the footnotes on the items it looks like they have renamed them twice.

Edited by dklawson, 26 April 2014 - 12:18 PM.