Topic: How well does an old liner need to be removed before applying POR15?

[q2418130103p]

I have the full por15 kit (the stripper, the surface prep, and the coat).  I just finished the part of the process where I swish the paint stripper around for awhile then wash it out with hot water.

90% of the liner came out, then after many many gallons of hot water and a lot of violent sloshing with drywall screws it was up to 99% of the liner removed. 

When I look into the tank I can still see a couple spots here and there with liner left over, and those spots look pretty well adhered.

Is that good enough to start the surface prep part, or should I do another round of paint stripper?

[cheftuskey121]

when I did mine, before I used the por-15 kit I used a whole container of MEK, and got a lot of old liner out, as well as a whole container of aircraft remover and got even more liner out....THEN I used the stripper in the kit and got even more liner out...pretty much nailed it. then the cleaners and bone dry bone dry bone dry (ie. hairdryer in there for hours and hours and hours). I applied the liner with success (from what I can tell). my tank looked like the septic tank at the bottom of the sunken titanic

I'm not 100% sure I removed all of the old liner, and I know I did not get all of the rust out, but the inside is covered with por-15 and nothing else poking through

[ekpent]

Was there a lot of rust hidden under the old liner ? I have never used the POR product,hopefully not like a sealed membrane product like Kreeme.But any rust left in there, even hidden is like a cancer waiting to grow.  I have been in the Red-Kote camp for awhile.
   The big question though after you get it cleaned well is do you really even need the sealer. For me its a last resort or pinhole leak situation.

[Really?]

I used thier stripper on the liner that was in the tank.  It popped and cracked a lot.  Then I lined with POR-15 too early, it did not stick in some places.  Used thier stripper again.  Waited about a week this time to make sure it was dry.  The second time stuck.  Lined it again.  Been fine so far.

In short, thier stripper works well.  But make sure it is dry in that tank before you do the liner.  Or wyou will do it again, cost you more money and make it easier to ruin the paint on the tank.  I ruined the paint on the tank the second time.

[cheftuskey121]

Was there a lot of rust hidden under the old liner ? I have never used the POR product,hopefully not like a sealed membrane product like Kreeme.But any rust left in there, even hidden is like a cancer waiting to grow.  I have been in the Red-Kote camp for awhile.
   The big question though after you get it cleaned well is do you really even need the sealer. For me its a last resort or pinhole leak situation.

Por-15 states that their liner bonds over any left over rust and prevents rust from growing/returning. I'll be the first to know as my tank was a great candidate to test out their product. I will hopefully not have to report back in the months to come but if anything funky develops I will let you guys know!

Good luck with the tank

[q2418130103p]

As far as I can tell POR-Strip is just Methylene Chloride, so paint stripper.  So nothing is really stopping me but laziness from putting in a bottle.

There is no rust under the old liner in my tank.

Their stripper did a great job, its just a couple spots here and there that have some old liner still.  One of the spots is the front corner, where there was basically a guarantee that a quart of paint stripper was sitting right on top of it.... and it still didn't get eaten through.



You can never know for sure that the entirety of the old liner is gone, unless you look in with a scope or something.  That being said, was there any old liner left behind that you could see before continuing past the strip stage.

[Retro Rocket]

There is no rust under the old liner in my tank.

Then why line it...?

[trueblue]

There is no rust under the old liner in my tank.

Then why line it...?

That's one thing that I always find intriguing, if all these tanks need lining now, how have they survived the last 30-40 years without a liner

[q2418130103p]

Well... I guess I should have posted this thread under 'other' bikes because I am actually working on a tank from 2000.  I just figured the question was generic enough to apply to SOHC4 as well.

So, the tank I am working on had some factory liner which was defective.  I just figured it came with a liner so I should put one back in.  Plus since I am putting new paint on the outside I figured I would line it now rather than risk damaging the good paint in the future.



So if it has no rust should I just not bother to line it now that I have (nearly) removed the defective liner?

[trueblue]

If you keep fresh fuel in the tank it will exclude any water and oxygen which will stop the tank from rusting.  I don't like liners full stop, I have seen too many fail and cause issues with carbs.  It's like removing the rust and putting something in there to replace it.

[q2418130103p]

Since the tank is completely cleaned of all fuel right now on account of running paint stripper and lots of water through it, and I don't plan on putting fuel in it until after I sand blast it and paint it, is there anything I should put in it in the meantime to avoid some sort of flash rust?

[nate85]

Since the tank is completely cleaned of all fuel right now on account of running paint stripper and lots of water through it, and I don't plan on putting fuel in it until after I sand blast it and paint it, is there anything I should put in it in the meantime to avoid some sort of flash rust?

i would think you could use a light oil and do a nice coat on the inside of the tank. not gonna hurt anything

[CafeDawg]

+1^  Mystery Oil.

Respect
CD

[CB750F2]

Add a mixture of 2 stroke oil and petrol to your tank, slosh it around to wet all surfaces and then drain. The POR 15 product is a good product but if you do have a leak how to you fix it? If you braze or weld the liner is damaged and you cannot - according to the POR 15 suppliers - recoat over POR 15. Pat

[Really?]

I had some pinholes in the bottom of the tank.  They had a repair kit for the outside.  Basically like a fiberglass cloth and the POR15.

[iron_worker]

I recently stripped the failing liner out of my tank.... the product they used was TOUGH but the application was spotty and so rust crept under the edges and caused it to fail. Where the liner was in tact (the bottom ... they probably didn't rotate the tank around enough before the liner set up) I had to use some steel wool taped to dowel to scrub it. Then soak it in stripper again, then scrub, then rinse, then soak, etc. It was a lot of work and took two cans of stripper to get acceptable results and lots of elbow grease.

I have chosen not to re-line because of all I have heard on here of failed liners. I'm finishing up my cleaning process with a vinegar soak to remove any remaining rust.

The beauty of not lining is you could potentially vinegar soak it every couple of winters to take out any rust that may start to show. The vinegar also won't hurt your paint.

IW

[trueblue]

If you do have any pin holes in the tank it is easy enough to use a little plumbers solder to fix them, I did that on mine nearly 2 years ago and it is still holding strong .