Sealing gas tanks

[panmarkski]

Bought a set of 61-62 tanks a few years back and just now getting around to fixing them. Had quite a bit of rust ,gunk,and who know's what else plus dents and creases. Cut a window on inside face to clean and repair and will tig up. Will have inside nice and shiny when done. Question. what kind of coating did Harley use or applies now inside gas tanks, or should I use a sealer, or leave bare metal? Thanks for comments,GREAT site
Mark

[katto]

I once had a chopper tank chromed and it seemed to rust on the inside but never seemed to be a bother thow. I would leave it bare.

[FlatHeadSix]

Mark,
The inside of the tanks were parkerized, or similar, from the factory. So, bare metal, with some sort of anti-rust treatment is the original way to go.

If they are absolutley clean and rust free, rinse the inside with some type of parkerizing solution, rinse them again with something like WD-40, and then keep them full of water free fuel.

mike

[NightShift]

Question. what kind of coating did Harley use or applies now inside gas tanks, or should I use a sealer, or leave bare metal? Thanks for comments,GREAT site
Mark

Dear Mark,
Great question! Bare is best right this minute. But I found a goober inside of some '65 tanks that were only ten years old when I got them. It was only smeared on the bottom of one side, and really sloppy heavy tar like stuff.

It looks exactly like the goober they used to glue in felts in the rocker covers. Same swabby touch too.

The whole point is nothing touches this stuff. I cant get it out if I wanted to. I thought I did once.

We may never know what it was,

[panmarkski]

found a company "Bill Hirsch" they make all kinds of automotive restoration products. they make a gas tank etch and also a sealer,called them and said it was impervious to alcohol and ethanol, said it had a poly vinyl base. I might try it,let you know.
...Mark

[PanPal]

What is the name of the sealer he has?
If you look through the knowledge base, you will find a lot of tank sealer discusion.

I really think the best thing is to weld any holes or cracks and not install a sealer at all. On another forum one of the members mentioned taking tanks to a place that tins copper kettles and have the inside tinned. This sounded like it might work but I never tried it. I'm currently making a tank and I though I might try to put some heavy weight oil in it and heat the outside of the tank while rotating it. My thought is it will turn a black color inside as the metal soaks up some of the oil. I would leave the cap off while doing this.

[1964 pan]

I used a product called "Kreme", on my 1964 tanks about 30 years ago. They are still in good shape. I have used Kreme on several tanks and the only problem I have had is sand blasting and holding the gun too close to the tank for too long. The heat made the Kreme turn loose. Other than that, now problemno.

[Cotten]

I used a product called "Kreme", on my 1964 tanks about 30 years ago. They are still in good shape. I have used Kreme on several tanks and the only problem I have had is sand blasting and holding the gun too close to the tank for too long. The heat made the Kreme turn loose. Other than that, now problemno.

My wife's rat also has Kreme from the 80's and in great condition.
However I have encountered more modern installations that failed miserably, as has been reported on many forums by many folks.
I fear that Kreme was forced to change their formula at some time in the 1990s.

There are many fine sealers, but sealers are not the problem. It is the P4gas.
The only way to eliminate the risk of a sealer decomposing it to eliminate the use of a sealer.

....Cotten

[john HD]

Mark,
The inside of the tanks were parkerized, or similar, from the factory. So, bare metal, with some sort of anti-rust treatment is the original way to go.

If they are absolutley clean and rust free, rinse the inside with some type of parkerizing solution, rinse them again with something like WD-40, and then keep them full of water free fuel.

mike

yes both my panhead and wla have a whitish looking phosphate coating inside. somewhere in my collection of books is a photo of the dipping process the factory used to prep sheet metal.

when i prepped my oem pan tanks for paint i found spot welds on the very rear of the tanks. my theory is that they left a 1/8" hole in the bottom of the tank until after dipped to allow the solution to drain. they look like the holes were gas welded shut.

i have never been able to verify this, but if true it would be a way to identify aftermarket tanks from oem ones.

john

[panmarkski]

john HD
took a look at the inside of my tanks, I see what your talking about, possibly little drains the factory sealed. I'm not looking to finish inside of tanks to original cond just something I won't regret down the road, trying to get another 50 years out of these tanks . thanks....Mark

[Lowbikemike]

I also have the small spot welds on my 59-61 tanks, I figured they were there for the same reason.

[john HD]

mark

i was thinking one could recoat the tanks using a parkerizing solution as mike suggested.

have you considered using reverse electrolysis process to clean the tanks and see what you have left of the original coating?

john

[Service-Guy]

Hope this helps. I work for a shop that does restorations. Have sealed dozens of tanks, I'm building a Bobber for myself right now and the only sealer I would recommend (because it's the only one I'll use, and I'll seal the tanks on my Bobber with it) is POR15. Check out their web site, look under Fuel Systems Restoration, you'll find what you need. This stuff is great, the new fuels won't touch it, I've never had it separate from the tank. Just follow the instructions and never worry about a leak.

Every one has an opinion, few have knowledge

[Cotten]

ServiceGuy!

My opinion of POR-15 is based upon experience.
I lost a great deal of money when it failed.

Annually I test many products in summer-blend fuels upon etched glass.
POR-15 invariably softens and expands, and falls off over-night.

GLASTEST.jpg

It is the big gray flake at the lower left.

....Cotten

[Hog54]

I put kreem in my tanks on both my bikes 15 years ago and never had a problem.http://www.jpcycles.com/product/720-469 ... medium=cse" onclick="window.open(this.href);return false;

http://reviews.ebay.com/How-to-use-the- ... LISTINGS:2" onclick="window.open(this.href);return false;