How do you get all the gas out of a tank?

[kevsLX]

A guy brought me the tank and fenders off a Wide Glide last night, but I can hear some gas still sloshing around in the tank. I've tried turning it every which way to get the remaining fule out but there's still some left. The tank needs a little body work, and I'm scared of a spark off the DA blowing me up

Any suggestions? Is there something I can flush through the tank that won't cause it to rust inside?

 

[ezrider]

Kev, whats up? i would recomend getting out whatever you can by just shakeing the tank upside down and put it out side away from any sparks or flames(just a little common sense, you would be suprised )and it should evaporare, make sure there are also no kids or pets around (not too much suprises me today ). then you will have the gas vapors to tend with, you might have to let air out for a week or so, the vapors are what you really have to worry about. a couple of years ago a friend of mine had a bad experiance fixing a gas tank.if your pressed for time and you have to use the stud gun or weld or grind you can fill it up with water, do what you have to do, empty the water do not dry with compressed air, it will promote rust dump in some dry gas and shake it up and get rid of the exess then let the dry gas fumes evaporate for a day or two. which ever method you choose make sure to get rid of the vapors, this can not be stressed enough.hopoefully this will get you in the right direction

 

[rex]

I take it this is a one piece tank.If the cap (right side),petcock and the crossover tube is pulled,you should be able to dump all but a few ounces.You might want to check that a crossover isn't blocked by crud if it's old.If it's above 80 degrees that should be gone in 2 days or less.I use a scotchbrite wheel for a die grinder to strip the filler area and get a spark here and there without a prob.Are you sure it isn't the fuel guage float you hear?If there's a plate in the bottom of the left bung with a few wires sticking up,the float assy is still in and it'll make noise when rotating the tank.Back when we were younger and dumber we had a game with 5 gallon reducer pails that started after doing a 'quick clean' on them to fill them with something else (and a few gas tank rewelds by myself).We'd set up an object about 20ft away and each of us would have a pail with the few remnants left when we changed to a new one.We'd lay it on it's side,remove the cap,line it up and pass a lit paintstick across the opening.Poof and it'd scoot about far enough to knock over the object if you did it right.I use this technique on tanks that need welding too,but.After dumping the gas and airing it enough time to be adequate,I flush it a few times with water until the small of gas is gone or extremely low.Pass a lit object across the largest opening and you might get a little poof.You have to be extremely critical of the initial cleaning taking into account the size of the tank,the material it's made of and welded,and the amount and size of the openings.Very dangerous and I recommend this to nobody!DO NOT DO THIS!There is a knowlege and skill required to do it without blowing welds,let alone injuring yourself seriously.This is for amusement purposes only and if I can't use my judgement,you're on your own.

 

[ezrider]

Rex, whats up? that friend of mine that had the bad experiance,well he cooked three quarters of his right fore arm, " luckily " it didnt blow up on him. "luckily" ment third degree burns on his forearm

, he said the flame only lasted a split second, thats how hot that flame was. special note to everyone be very cautious of high octane fuels (racing grade ) , the vapors stick around MUCH longer than regular grade fuels.

 

[kevsLX]

Thanks for tha advice fellas. The sending unit is still in the tank, so that could be some of the noise I'm hearing. Looks like a hot sunny day today so I'll set it outside for a while and see how much evaporates out, then try the water.

 

[rex]

EZ,glad your friend didn't have a catastrophy.I have misjudged before but luckily it was it just made a little more noise and bigger flame without blowing a weld or me.Now in my old wimpy age I do this much less and like your idea of filling with water.

Kev,if you're just doing prep and not welding,try to avoid the water.If they're stock unsealed tanks it just adds more rust.Set it in the sun a day with everything open and another should definately do it.The right side is easy to see in through the filler bung (it'll be orange but dry),but the left side is the prob.I poke a piece of insulated wire like in your car wiring through the crossover tube to be sure it's open.It might not dry out as fast but I plug all openings when the prep begins.Since the crossover is the only open spot on that side (unless you're brave enough to screw with the float assy.),plugging it along with everything else will usually be fine.If the dent is in an area that can be pulled with a stud welder,it's also 99% possible you can just fill it and blend it out.I've had **** poor luck pulling dents on tanks that are in an area that needs to be pulled because the high edge is so pronounced.Usually these dents are in a high crown area and studs just won't overcome the pressure,so I fill and melt it out if they don't want new steel.

 

[kevsLX]

Hey Rex. I would like to avoid getting water in it, and it is a stock tank. The dent is on the left side, right on the front but almost on the underside. You almost couldn't see it if it was mounted on the bike. He dropped it when he was taking it off. Bad thing is this tank has been painted twice over top of the factory paint and it's chipped pretty badly in some areas. I really want to take it back to bare metal.
I don't have a stud welder to pull it though

Would using filler be "hackish"?
I want to do it right and have it last, even if I have to pay somebody to pull the dent out.

 

[rex]

That sounds in a bad place to pull.Some say it's hacking but I don't think so if done right.If there's a really high edge around it from an angle hit I try to pull it but usually just end up hammering the high down a bit.A straight on 'perfect' hit I try to tap the whole edge a touch lower.Once you get the dent filled and shaped to the edge of the dent,another coat spread out a couple inches usually will melt it out.If you hit the high edge and it still feels funny,put another coat on but extend it out farther.If it's in the area I'm thinking,you might have to work out 4 or so" to melt it out.I'd definately strip it,there's alot of paint there,especially if it's 2 tone in there somewhere.I do all my body work over DP epoxy,but I almost always start from steel.I don't like water in my tanks either,the inside is probably already covered with an orange tinge.You'll probably be better with stipper,just stay away from openings ,seams and welds.The repaints will come right off but the factory stuff is harder.I finally got my tank stripped yesterday.The reclear (like 8 coats) peeled first shot but the factory 2tone took 2 more heavy coats and I still had spots that needed a good 180 to hit metal.If you sand it with 40 grit or scratch it up good first the stripper will work faster.Don't be surprised to wait 20 minutes for a coat to work,but keep it wet with another light coat if it starts to dry up.Wrapping it with thick visqueen will slow down the evaporation process.I use a 3M Scotchbrite on a die grinder to remove everything else possible (it's a black 1/2' thick wheel that mounts like a cutoff wheel).Anything I can't get with it gets sand or bead blasted.Make sure all openings are sealed up extemely tight though for blasting,the dust gets in places really easy if there's even a thought of a leak.If I can't get a tight fitting cap for the petcock or crossover and vent tubes,I wrap masking tape tightly around them until the tape is about 6 wraps thick and pinch off and rewrap the end.The gas filler gets a wide double layer of 2" tape so it's definately sealed to a few inches of steel surrounding the hole.This is the quickest way I've come up with to strip a tank that isn't sandable,but it still takes a while.Don't forget to neutralize the stripper by red scotchbriting while flushing with plenty of water or prep wash(the latter gets expensive).Post some pix when you're done.

 

[kevsLX]

Rex, man I really appreciate the info. Thanks.
He wants the bike completely red and white checkerboard

Can you say "Pizza Hut table cloth"?
Trying to get him to do something a little cooler. I'll post pics when it's done.

 

[rex]

Hahaha,some of these combos.I did a pearl white with fine gold flake for someone.Reminded me of a formica countertop.Post some pix for sure.Oh,no thanx required,but you're welcome.

 

[rex]

Excellent idea Scott,I'll have to try that next time.Never even thought of it.

 

[kevsLX]

Damn, that is a good idea. I let it sit in the sun and it seemed to have evaporated out, anyway I just shot an intercoat clear on it not 5 minutes ago. He came off the checkerboard idea to turquiose with ivory flames. Looks pretty sweet, I'll throw some pics up after I stripe it out and all that.

 

[Scott Gardner]

I didn't see this mentioned yet, but to help get rid of the last bit of gas, I've had good luck sticking the end of an air compressor hose in a tank, and just letting a trickle of air run into the tank for an hour or so. This gets the gas fumes out of the tank, so that more gas can evaporate to make new fumes. This evaporates that gas a *lot* faster than just letting the tank sit there on its own, since without some kind of forced ventilation, the gas fumes don't have much incentive to leave the tank.</cr>
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Scott

 

[mcd]

The best way to 'inert' a tank is to put in about 1/2 pound of dry ice, as long as the ice is changing into co2 any fuel or fumes can't burn or explode. Works great cause you can tell when the co2 is active, since it is very expansive.

 

[Mac_Muz]

In the past I have had to weld used car gas tanks the same day.... I ran water thru them as I welded and blew them dry.... I never had any flashes or problems with rusting.

In those days the gas that tremained went with the water, but you can use the above air dry first then water I would guess....

Sorry to be so late on this..... Mac

 

[Nathan]

alright dude this is what you do, take a long piece of shop rag and stick it down in your tank and let it absorb the gas then pull it out.

 

[dragon]

I had a welder in town bring in some stuff to get painted and I asked him the same question. He said he takes the mig and just turns off the wire feed and gases the inside. I showed him a tank that had to be done and he just went ahead and didn't even try to drain it further just turned on the panther and after a couple of mins. put the dent studs and let me finish.. he said he has welded tanks with fuel still in it...scary but proven..

 

[Jeremy Farny]

kevsLX

Just take a garden hose with water and fill the tank up with water, dump it out, flush it again, and then go in the shop, take your air hose nozzle, stick it in the gas cap hole and blow it dry. I've done it, it works fine.