Author |
Message |
source_sco Samba Member
Joined: October 28, 2010 Posts: 14 Location: california
|
Posted: Wed Apr 22, 2015 9:59 pm Post subject: strange por-15 reaction |
|
|
hey guys. a friend of mine was generous enough to let me have a can of por-15 tank sealer which he picked up at the pomona swap meet this past weekend. a free can was just the motivation i needed to pull my tank and give it a good cleaning and sealing. i decided to use apple cider vinegar since the tank did not have a terrible amount of rust. after allowing the vinegar to sit for a whole day, i flushed the tank numerous times with a heavy spray of water...then i let the tank sit and dry for another full day. before pouring the por-15 i used a compressor to get rid of any moisture which may have been left behind. i then proceeded to pour the entire can of por-15 into the tank and slowly swooshed it around as per the instructions on the can. once i was satisfied that the whole inner surface of the tank was covered, i let the tank sit and drained all excess pot-15 back in to its can which i then closed tightly with the lid. i went in the house for a few minutes and when i came back out i saw the lid of the can on the floor and the por-15 itself had swollen up and was pouring down the side of the can...it looked like the spray foam the is used for insulation. what could have caused this? does por-15 have a shelf life and mine was no good anymore? could it have been tainted? anyone have a similar experience with por-15?
|
|
Back to top |
|
|
Pinetops Samba Member
Joined: March 24, 2007 Posts: 2987
|
Posted: Thu Apr 23, 2015 8:19 am Post subject: |
|
|
It's probably fine but next time I'd skip the tank sealer. Just clean the rust and reinstall. If it can't be cleaned with CLR or whatever and a chain or bb's then it's time for a new tank. Those tank sealants can and will flake off over time. _________________ "A rolling bus gathers no rust." |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
|
Posted: Thu Apr 23, 2015 9:20 am Post subject: |
|
|
Yep.....you put the POR-15 into the tank.....swooshed it around and then put it back in a sealed can. This happened because you still had rust or iron oxide in your tank probably aclityle bit more left than you thought.
One of the key ingredients in POR-15 is phosphoric acid. Thats what reacts with rust (iron oxide)...and converts it to iron phosphate. Its an acid reaction and it fizzes and out gasses.
The problem is that vinegar is not even close as a rust remover and it leaves to much residue because it still has some sugars in it. Also unless you are using phosphoric acid....any acid including vinegar should then be neutralized with a sodium bicarb rinse and then several complete water rinses.
You got rust back in the POR and that rust was fizzing with the phosphoric acid and created foam.
The way you are supposed to use any phosphoric acid product is to pour what you need into the tank or on the metal....treat it and then dump the excess into a seperate container. Then you can use the uncontaminated portion for a second treatment if necessary.
The POR-15 metal prep is a phosphoric acid based prep. It has more phosphoric acid than the coating itself. Its purpose is to dissolve crusty rust and convert surface rust to black irkn phosphate...which makes killer primer.
In serioulsy deep crusty rust you need to use a real acid like muriatic/hydrochloric. Then you neutralize. Then its going to flash rust from within minutes to overnight.....let it....then use Ospho or diluted phosphoric acid or POR metal prep to convert that micro thin flash rust to an iron phosphate primer....and then put on the POR-15 coating.
Your tank will probadly be fine.....but thats what happened to the POR....which you would have been throwing away anyway. Ray |
|
Back to top |
|
|
source_sco Samba Member
Joined: October 28, 2010 Posts: 14 Location: california
|
Posted: Thu Apr 23, 2015 10:54 pm Post subject: |
|
|
thanks guys...now it makes sense. as for the tank..well the por that adhered to the inside metal actually peeled off this morning. im picking up a used tank tomorrow and ill be putting this tank away until i can get around to taking it somewhere and having it cleaned and sealed by someone that knows how to do it. thanks again guys... |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
|
Posted: Fri Apr 24, 2015 7:46 am Post subject: |
|
|
source_sco wrote: |
thanks guys...now it makes sense. as for the tank..well the por that adhered to the inside metal actually peeled off this morning. im picking up a used tank tomorrow and ill be putting this tank away until i can get around to taking it somewhere and having it cleaned and sealed by someone that knows how to do it. thanks again guys... |
Its just too hard of a thing to get epoxy based products to really, stick. To many, chemical reaction issues. In your case the vinegar is your most probable problem. Its not the proper product to use. Its not a clean acid and its way too low in solution strength to docanying useful for this use. Its solution strength is 5% or less.
Also....I agree with the previous poster. If you have no rust throughs just lots of surface scale.....acid treat the tank....which will dissolve all the rust...ALL OF IT....right down to bare metal. Then use baking soda and water to neutralize it. Then rinse, rinse, rinse.......then dry it .....and let it sit. For a day to flash rust.
then pour in a pint of ospho and slosh for 10 minutes. Discard and pour in another pint. Repeat.
Then......you MUST let the ospho dry on the surfaces for 24 hours. This is the mustake most make. They rinse with water or solvent, to remove the ospho residue...which stops the chemical reaction you are working for.
Once you do all of this.......as long as you keep fuel in your tank it will likely never rust agajn in your lifetime. Ray |
|
Back to top |
|
|
g3bill Samba Member
Joined: March 30, 2015 Posts: 247 Location: So. Cal usa
|
Posted: Sat Apr 25, 2015 7:09 am Post subject: |
|
|
I think also 1 day isn't long enough to dry a tank, must have still been moisture in there. I like the info replies on the correct way of preping the metal, copied that;) _________________ I have Dial-Up an a hole in my pocket:)......Where are the 3 Stooges when we need them:)
'67 Camper PT westfail w/tent, hammock, jump seat. uping the motor to 1900 w/88bore/78crank.
& will be using carb 34 pict 3 ....Someday?
'82 Toyota 4x4 5sp PU lb, daily driver
Many Corvairs /& 4 rag tops
'63 Chevy 20 Truck w/4sp 292
Want, white plastic end pieces for dash grab handle |
|
Back to top |
|
|
source_sco Samba Member
Joined: October 28, 2010 Posts: 14 Location: california
|
Posted: Wed Apr 29, 2015 12:55 pm Post subject: |
|
|
i really appreciate the help with this guys. the used tank i was supposed to pick up was sold to someone else....so i decided to go with my second option and just have someone do it for me but im having a hell of a time finding someone that will do it. i called some auto shops and they wont clean out the tank....and the one shop that would do it wanted $250! the rest just didnt know how to go about cleaning the inside. my best bet is to just give it another try myself. ill try the ospho method that raygreenwood suggested. thanks again for your help guys! much appreciated! |
|
Back to top |
|
|
B Ramsey Samba Member
Joined: February 05, 2006 Posts: 477 Location: Ramona ca.
|
Posted: Wed Apr 29, 2015 2:33 pm Post subject: |
|
|
I seal my tanks with Red-Kote, from a midwest state, not california. Works great, doesnt flake off, seals small holes. Model A, numerous ATC's, jerry cans, etc. |
|
Back to top |
|
|
Emeraldlion Samba Member
Joined: April 13, 2005 Posts: 743 Location: Texarkana, TX
|
Posted: Thu May 07, 2015 8:38 pm Post subject: |
|
|
I just had to re-do a botched job from a radiator shop. Idiots did not clean well and put in red kote. I took it back and they pretty much put in more red kote, still dirty. I don't know about the por but I used 2 gallons of MEK from lowe's and a TON ob bolts and nuts and washers in the tank. Let it set for 5 hours, sloshed it around good, set some more sloshed it around. It took the red kote right off. Be careful with the MEK it is NASTY hazardous. I drained the MEK into it's original containers (it was now the color of koolaid) and rinsed the tank with water. Then went in 3 gallons muriatic acid from home depot. Full strength not the new NEXT crap. carefully sloshed it around and let it sit for about and hour. drained off 2 gallons and gave it some good shakes (careful not to spill!). Then in went some baking soda ...fiz fiz. Then rinsed with buncha water. My tank was shiny new inside! let it set out to dry for a day. Got all the bolts out, put in about a pint of ospho and sloshed around to be sure, drained that off and let it set. All in all was about 60 dollars worth of materials and a couple of days but I bet this tank will outlast me now. Should have done it myself from the beginning.
Note- all of this was done OUTSIDE in VERY good breezy dallas ventilation. The MEK has some serious fumes that can chemical burn your lungs and possibly give you cancer, the muriatic acid will give off fumes that WILL burn your sinuses and airways if inhaled. |
|
Back to top |
|
|
|