Topic: "Flash Rust"

[gaijin]

Hey everybody,
Finished with the POR-15 kit a few days ago and I think everything went ok. I'm about to fuel up the bike and see. But while I was drying the tank (with the hairdryer) after the acid wash, the shiny metal started to develop light orange streaks which spread to pretty much the whole interior of the tank, even as I dried the tank! I'm guessing this was the flash rust the POR-15 kit warned about. I wish I'd gotten photos but I was in a hurry to get the thing dry and sealed ASAP. Anyone else have this happen? The kit says the sealer can bond to the rust so it should be fine, but man it rusted right in front of me in only a few minutes..!

[Bob Wessner]

Just curious, how long did you keep the acid in? I also used the POR-15 kit, but decided to only use the Marine Clean and the Phosphoric acid (Steps 1 &2), skipped the liner. I didn't experience this on mine. It still looks good, almost new inside. I did the work more than a year ago.

[gaijin]

Bob,
I kept the acid in for about an hour. I'd actually read through your POR-15 experience prior to starting mine and was condsidering skipping the liner, until I saw the rust creeping. Maybe it's the weather.

[Bob Wessner]

I skipped the final step primarily because I had reservations about my getting it evenly distributed on all surfaces and decided I would make every effort to keep it topped-off, etc. and otherwise take better care of it than I had in the previous 22 years.. which would not take much effort, trust me. 

[Tim.]

The POR-15 liner spreads REALLY well.  It's amazing really.  I did mine, and it looks like someone sprayed the inside. Very even coverage.

http://www.sohc4.us/forums/index.php?topic=1586.0

I did marine-clean for 30 hours, and then the acid for an hour or so.  Then dried like crazy and then the liner.

Where in the instructions do they talk about 'flash rust'?  My only complaint about the instructions was they weren't as detailed as I'd hoped.

[shack]

Hi everyone,
I also did POR15 on my bike and it worked great.  I had trouble getting it dry.  This was 3 years ago and I can sorta remember getting some light flash rusting, but I have not had any problems since and I did do the liner.  Which did spread great.  it does look like someone has sparyed the tank.  Compared to an MT250 I just bought which had another product done on it some time ago the POR15 is a very slick job. 

My 2 cents
Andrew

[Robert]

So for planning this, how long does it take with the por 15 set to get it done really good. Are we talking like 3 days or is it more like a week? Bad rust in the notches, lightly rustes elsewhere. No holes.

[Tim.]

2 days.

30 hours with the Marine Clean
1 hour with the Metal Prep
1 hour drying
1 hour with the Liner

Of course, then you have to let the lining cure.  Mine sat for 2 weeks before I put gas in it (circumstances).  Minimum is 5 days.

So, if this is your only tank, you're out of commission for nearly a week.  Don't rush it.

[gaijin]

Tintin,
the instructions only mention flash rust briefly (right after the section on drying)

"NOTE: Once the metal is treated, it can flash rust. Though the coating is designed to bond with any new flash rust, ideally you'll want to perform the forced air drying promptly after draining the tank, and coat the tank with sealant soon after drying it."

Maybe my piddly little hairdrier wasn't beefy enough for the job  but the coating looks solid. I should have timed the process better so the drying coincided with the afternoon sun!

[Buffo]

i have used por-15 on all of my bikes. To dry my tanks i used a paint strip gun. Most of them get REAL hot, so you actually need to be carful you dont burn your tank paint. (paint stripper gun).

Don