V Twin tank sealer?

[FNG1]

I am working on a 1941 FL project with V Twin repop tanks. They recommend sealing. I have read so many reviews and I still can't decide what to use. Maybe Red Kote, maybe KBS? What about hot dip galvanize? Any one use these recently. The tanks leave a lot to be desired and need some cosmetic work to finish, but I would like to forget about them after they are mounted. Also what would be good to use to seal the engine cases. Thanks. P2240387.jpgP2240388.jpg

[Robert Luland]

Use the red coat. Bob L

[FNG1]

Thanks Bob. Any suggestions for prep.

[harleytoprock]

I would pressure test and repair with tig welds if there are any leaks. Then I would clean the tank inside surface with a etch cleaner, neutralize and then parkerize . To parkerize, the tank can be heated in an oven to about 180 F. and then pour pre-heated parkerizing solution in the tank. I think using tank sealers is a crap shoot with our ever changing fuels and should be used at a last resort.

[T. Cotten]

FNG1!

The best way to "pressure test" is to cork up each tank securely, and then immerse each one in a tub of hot water. The heat will build pressure safely, and bubbles will quickly locate any issues.

Any sealer would give you fits in the future if any repairs are needed, such as for a cracked mount, as it would require removal before any weld or silver-solder repairs.

Good luck!

...Cotten

[FNG1]

Thanks harleytoprock. I like the idea of it, the one filler neck and the fuel shut off are brazed . I looked in the tank with a mirror and it was welded first but I could not tell if any braze got on the inside. Definetly some flux or burnt oil. Would the braze affect the park?

[FNG1]

Thanks Cotton. I will try your way. The Setup I used to pressure test the tanks involves rubber caps and plugs with a tire valve stem, any thing over about 5 psi pops the caps. I am good as far as leaks but I think these are bare steel of questionable quality and I want to try to rust proof them. Maybe I'm worried too much about nothing. Thanks for taking the time to reply.

[harleytoprock]

I have parkerized some parts that were brazed and the Parkerizing process just does nothing to the brass.

[TechNoir]

As has been said, if you can repair a tank properly then that is preferable to a liner. If you do have to use a liner then I have had good results with POR15.

Re your pressure test corks. I also use rubber corks but then secure them with first masking tape to protect any paint and then duct tape. This prevents them popping out. Also for the pressure test rig I use a 12 volt tyre inflater rather than a big compressor. I find that it is quite controllable because it pumps air in quite slowly.

If your tanks are sound then, as has been said above, think about other options rather than sealer. If they are sound and clean then why not just leave them bare metal like they were from new?

John

[jim d]

The pressure tester that I made has a small gauge on it to register the pressure. I use about 3 lbs. I have a small hand pump similar to a suspension pump, but a hand tire pump or bicycle pump works fine.

[T. Cotten]

Jim D!

So... how do you see where it is leaking?
Soap suds?
Regulated pressure is good, but hand pumps and mattress inflators have gotten enough people in trouble testing manifold leaks that I cannot endorse them. Especially when a hot bath works so well. Today I tested a GX brass float in hot water,... and surprisingly it was fine! (Even though it rattled like a bell from solder loose inside.)

And John!

My luck with Por15 was anything but "good".

The issue most have with bare metal is corrosion, particularly with ethanol fuels, so we should consider two kinds of "sealers": Some to seal leaks (soldered-construction tanks have their own issues), and some to seal the surface from corrosion.

Parkerizing would seem great for the latter, but since the process depends upon its affinity for oils, and fuels will quickly steal that away, it makes me scratch my chin.
My favorite is an isocyanate urethane, but it just gets snivels from those who haven't applied it.

....Cotten

[FNG1]

Hi Jim, I used the gauge on my inflater. Pictures show more than I could explain.P2250390.jpgP2250389.jpgP2250391.jpg.

[TechNoir]

Hi Cotton, I can only go with my own experience with POR15 which, as I said, is good.

However in the UK there is still one vendor where I can get ethanol free gasoline which is what I mostly use in my old bikes and I also drain the tanks over winter. Perhaps the lack of ethanol (mostly) makes a difference?

I agree that isocyanate’s are great at resisting all sorts of chemicals.

John

[FNG1]

Hi Cotton, yes I did use soapy water in a spray bottle. I only used a few psi, as I said any more and it would safely pop the rubber cap before getting me into trouble. Now that I know another way I will try it in the future. I have decided against sealing for leaks, but I want some corosion resistance. I am curious, do you think the fuel would alter the parkerizings ability to protect against rust? Or that I would not be able to get the inside of the tank clean enough? Also do you have a favorite Isocyanate or will what ever I find on the web do? Thanks

[exeric]

By all means, test your tanks first. If they're leak free; everything is jake. If your tanks are leak free, harleytoprock's suggestion of Parkerizing the inside of the tank is a good one in this day of mystery gasoline; but that could be challenging in the execution. I guess you would just pour the properly heated solution into the tanks and let the miracle of chemistry do it's thing. Tank liners are a hail Mary solution to gas tanks that can't be realistically repaired, which is more common on early (non replaceable) soldered tanks. Tank sealer can be easily removed with paint remover, followed by MEK, or acetone. Stinky, but effective. As for reproduction tanks. . . Just buy another set if they fail.