Topic: Proper course of action?

[kidrcth]

Bought a tank a bit back. Was told it was a good tank, of course, they always are right? Start prepping tank for paint and notice some spots with filler already, keep going and rust underneith. One even had a spot through. I soldering that spot so for now it is good.

I'll explain my plan going forward and if I am doing it wrong please let me know. I'll finish removing the filler to expose all rust, remove as much as possible before acid prepping the rust. Then refill and paint.

The tank will be sealed with por15 sealer.

Any other prep required to make sure this rust doesn't haunt?

[strynboen]

glass blast it..so the rust is total gone..and prime..then the rust is cured..and vill not blow up under the paint

[kidrcth]

Nervous about blasting such thin metal because when I blasted yesterday it knocked away enough material to create a hole that had to be soldered.

[78whiteorbs]

Naval jelly

[ekpent]

 That tank is looking like its getting close to risky usable maybe, see what looks like more pretty severe rusting along the bottom edge ?. Look it over real well and see what happens when you acid it out. It would be a shame to put a nice paint job on it and have it start bubbling off. The tank sealer may save it but nothing last forever, especially Kreeme coating. People say good stuff on the POR though.

[78whiteorbs]

Naval jelly

Naval Jely won't remove the filler. Only sanding/grinding/blasting will. Use glass media and keep the nozzle angle more acute than perpendicular to the surface. It will remove the filler faster and won't attack the base metal as severely.

I would blast it then de-rust it, then seal the interior with a quality liner (Caswell or POR-15).

"I'll finish removing the filler to expose all rust"
My suggestion was taking into consideration that he could and had removed all the filler. The naval jelly would seek and destroy and specks hiding in in any porous little nook and cranny so itd be a safe foundation for filler and paint.
If he didnt have a media blast cabinent and was able to remove all the filler .....then my suggestion might make more sense.Maybe I misunderstood his post though...wait no my burnout brain does recall he said he didnt want to use media because he blasted through it already. Not trying to be a smart ass either lol....id be leary of spending alot painting a tank like that but if it was more a budget rider tank Id roll the dice....

[78whiteorbs]

That tank is looking like its getting close to risky usable maybe, see what looks like more pretty severe rusting along the bottom edge ?. Look it over real well and see what happens when you acid it out. It would be a shame to put a nice paint job on it and have it start bubbling off. The tank sealer may save it but nothing last forever, especially Kreeme coating. People say good stuff on the POR though.

Agree

[78whiteorbs]

Yes, that's why I warned him off expecting Naval Jelly to remove the filler (due to his aversion to finish blasting the tank).

It's pretty common for solder to fail if you blast it. There's no fusion between solver and the base metal like brazing or welding. Blast it to bare metal. Fix it once, right, line it and use it. It's part of a restoring a bike 

Sorry perhaps I misunderstood his wording-

[78whiteorbs]

Nervous about blasting such thin metal because when I blasted yesterday it knocked away enough material to create a hole that had to be soldered.

Just re-read this, what were you planing on finishing removing the filler with? Sounded like you didnt want to use media for fear of blasting through. I have found crushed glass to be far less abrassive than glass bead when you want a slower and slighly less abrassive media. They also make coal shlag (devils tooth) in different grades if you are concerned with not being able to control the blast power by angling you tool properly. Just a thought...
So many ways to skin a cat. Sure Calj's opinion is %100 on point. A tool is only as good as the hands weilding it!

[kidrcth]

So i finished removing the filler with a brass rotary brush. Causes minimal damage to the metal and removed the filler easier. I went and got some "nicer" abrasive, glass media. I normally use the black diamond stuff that's very hard on materials. It finished removing the rust and no new pin holes were exposed. I went ahead and blasted the bottom seems and they are fine. I did find another pit that went through on the bottom flat spot on one side. Removed the rust and soldered it shut so it'll hold sealer. I then treated it with more phosphoric acid to convert the rust.

The POR15 gas tank kit should be here this week.

Should i seal it up then prep the outside, or start prepping the outside then finish after the seal job?

[Terry in Australia]

"F" tanks are prone to rusting internally, way more than "K" series tanks, so looking at that moonscape on the outside, I'd hate to think what it's like inside? Junk it and find a better one. Tim Kasper (Kghost here) sent me one from Texas, and it was perfect.

Don't buy one that's been repainted if you can avoid it, I bought the first F tank from a dude in New York who swore that it was perfect underneath, when in fact some dick (probably the seller) punched a sheet metal screw through the metal to pull some dents, then just filled the holes with Bondo............. Cheers, Terry.

[kidrcth]

The inside is why I bought the tank, it is perfect.

[Terry in Australia]

That's good mate, just a pity that the outside is tissue thin...........

[754]

 for it to rust there. it was probably lying on its side. Easier to fix than seam rot..

[kidrcth]

I would love to get a rust free nice and meaty F tank. But obviously I was an easy sell when I paid $200 for this tank.

I'll finish prepping the outside with some self etching and hopefully it holds up for the seal.

[Terry in Australia]

Yep, 200 bucks was a rip for sure. If the inside is perfect, don't line it, fill all the external pitting with solder and spread the solder over the whole damaged area to hold the solder together, paint it, and with luck it should be OK. My biggest concern is that if you drop the bike, it might rupture. Cheers, Terry.

[firebane]

I picked up a 76 550f tank for cheap and glad I did. When I started to derust the tank I ended up punching a hole through the tank

[strynboen]

yes its my nightmare..on repareid and fiberglass tanks..if they open up by a crash..and you get" socket" in fuel...and you  meet a spark..and light up..like ghostrider...

a good metal tank..or proper solderet/repaerid tank  is solid as new..but a thin beercan thik Shell,,just vaiting to blast open....and the Money on paint..its just so expensive to get a good paintjob..vith decals and stripes..its kosts more then a good rustfree tank..and it all vasted if pinholes brake through the nice paint..and bubbel up the job

[b52bombardier1]

You may need to use some of that blue painters tape on those holes to keep the POR15 from seeping through. Then peel it away after it cures but I have lots of faith in the POR15 to make that repair.

Just go slowly on the internal rust removal because poor preparation there can cause you problems later. My tanks often take 3-5 days to derust before pouring in the urethane.  Boiling the phosphoric acid also speeds up the rust removal and leaves a good coating of iron phosphate. Use a heat gun to remove all water before the urethane goes in because it will not stick to water.

And finally, pour as much of the urethane as possible out after making certain you have it all covered on the inside. Too thick of a urethane layer can delaminate later. But in your case on this tank, I might leave a little extra inside oozed up in that pinhole area.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

[kidrcth]

I was thinking the same thing as far as lining all the spotty areas with something to make sure the sealant stays inside the tank. I know soldering tanks is most likely a good repair i just dont trust it alone, solder plus sealer gives me a little bit more confidence.