need help with rusty screws

hi, i need to get the rusty screws out that hold the sending unit in the gas tank. i was hoping not to pull the tank. i've tried big screwdrivers. lot of penatrating oil. still no luck. any good ideas???

 

Most commonly used means of violence are inappropriate here...they'll either cave in the tank (like impact driver!) or blow you to bits...so that is a major handicap with poor access.
If no go with screwdriver, bite the bullet and remove tank...I assume some sort of round or pan headed screws...it may be that only reasonable next step would be to go straight to vise grips, new small ones with sharp teeth!

 

You might want to try a diffrent brand of peretrating oil. Be sure to clean the area being sprayed very good with a small wire bruch, then spray. I like PB Blaster. A little old trick is to also hit dirrectly down on the head of the screw with a brass drift and a small ball pean hammer. Brass drift in this case simply because of the gas and fumes, you dont need anything that could spark. You might want to tap around the area of the head of the screw also. Clean the area again, and spray your Blaster.

 

transmission fluid cut with accetone.50/50 what i use and a good pair of vice grips.good luck let us know how it turns out

 

Another of the VERY few tricks you can perform without ruining a gas tank: If there are washers under the screwheads, get a punch and tap them back and forth. Any movement here will tend to help, and if they are lock washers they may well crack ito 2 pieces that will come out...

 

Try to tighten and loosen and repeat. If the sender sits up off the tank drill off the heads and remove the studs with vice grips. Sometimes a left had drill bit will rattle and heat up the screw enough to get it out.

 

If its GM it could have clutch head screws. Vise grips is the answer.

 

Gets my vote also

Tig.

 

btt

 

I am fond of the impact driver. You will have to go at it from a stand point of only hitting it hard enough to pop the screw and not so hard as to cave the tank in, but tanks can be pretty resilient if they are still solid and not rusted badly. I like the kerosene/ tranny fluid mix as well but there used to be a product on the market called Gibbs, it was a blue fluid with what looked like graphite throughout it, and I had great success with stuck fasteners when I used it. I have not seen any for quite some time though, so may have to improvise.

 

both of you are quite crazy if you're serious about drilling or using a punch on a gas tank. please, tell my you're saying it tongue in cheek?

 

The trick I have learned that works really well (but not necessarily on fuel tanks) is to heat the offending bolt/nut/screw with a torch until it is red hot. Then quench it with WD40. It will smoke incessantly and smell funny, but after the temperature shock, most bolts will unscrew with finger pressure only. I work on a lot of rusted metal, and its the best way I know to get things apart without destroying your work piece.

 

all is not lost. if you already have the tank out, use a hot water power washer or steamer and clean inside the tank thoroughly. when you think it is clean enough to weld on clean it one more time. tack weld a washer on the screw head, then tack a small piece of rod or anything to the washer and turn it out. actually sometimes just the heat of washing good can be enough to be worth a try turning the screw again before welding. remember wash wash wash. good luck and be safe. often times we work ourselves into a corner and waste time when all it takes is just biting the bullet and doing it.

 

So you're going to use a torch on a gas tank until the bolts are red hot.

 

And after the explosion, you won't have fingers (or worse) to do much of anything

 

Wasn't there a thread on here about tacking a handle onto a driver bit and turning it while tapping the bit with the air chisel? I'll go look for it...


Thanks to SamIyam:


http://www.jalopyjournal.com/forum/showthread.php?t=6015

 

If the tank is out and rid of ALL fuel,try an old woodworkers trick, use a soldering gun on the top of the screw. It will generate heat to a specific area and out she comes.

 

KABOOM !! What is a little explosive expansion between friends?

I would never advocate torching a fuel tank, although I have seen it done in a junk yard much to the surprise of the torch operator. (he was blown back 15 feet)
I have also seen someone weld on a fuel tank by filling it with water (completely) I am not brave enough to try that, but I am just saying

 

done that. its the safest way to use ANY sort of heat on a vessel that's had fuel in it... better have a REAL hot welding rig... you'd be amazed at how fast that much water will wick away any heat you can make.

the solution i've come up with since thinking about this, assuming the tank is to stay on the vehicle...

coat the heads of the screws with a THICK coat of axle grease, take a cold chisel and bust the heads off the screws. once you have the sender out, you can reach in with an angled jaw pliers and pop the remains of the screw shanks off and out.

just my 2 cents... but after taxes and my wife, its about useless

 

Several ideas here would work very well on cars in the Middle east

 

The BEST penetrant I've used is Kroil. It's made by Kano Labs in Nashville,TN. Spray it on the screws and let it sit overnight. 95% of the screws will come out. Another
trick we used to use on fuel panel screws was to use left hand drill bits. Hope this helps!!

 

there was a thread on earlyer about customizing a air chisel and bit for removing rusted screws, try that out- it raps it enough to loosen the screw.. we use em alot in the aircraft world cause wwe got hundreds of screws

 

i,ve welded many tanks filled with water. fill it to the top, weld a washer or a nut on the screw head and the heat should break the rust loose. that's FULL OF WATER!!!

 

You are all going to call me crazy, but the best way to put any heat to a gas tank is to fill it full of... GAS. yeah thats right, gas. lol. No s***. Gas is not flammable the vapors are. However I say anyone willing to heat, or weld a gas tank full of gas is completely nuts. So for the next best way to heat or weld a gas tank: (I have done this 5 times. and still have all my fingers and eyebrows). Here's what you need: 1) a car (other than the one the tank is out of) without catalytic convertors. 2) some radiator hose, dryer ducting, or any piece of hearty tubing that will fit over the fuel fill neck. 3) An hour or so of down time. Fire the car, make sure you are in a well ventilated area and that the car isn't prone to overheating. Hook the tail pipe of the car to the fuel tank using the dryer duct. Use rags, duct tape, the nieghbors cat, what ever you have around to make a decent seal at the tailpipe end. Also seal the filler end side but leave some sort of opening for vapor to escape. The pickup tube is usually sufficient. Bring the car up above idle 8-900 rpm. Wait. After an hour you will not be able to touch the tank. This will boil out any fuel vapor and make it safe to weld to. Filling it full of water almost always results in a crummy weld and is a mess to clean especially if all that is being done is bolt extraction.

 

I have heard of the above method as well as the water method. One old timer told me when he was racing that they would braze the tanks with a blowtorch right there in the pits while the gas was pouring out. If that doesn't pucker you up tighter than a snaredrum I don't know what will.
Since the whole idea of heat on things that go boom scares the piss out of me, I recommend a concentrated hit or two with a hammer on the back of a screwdriver seated in the slot of the screw. Then try to tighten it and then back it out. Someone else mentioned this. It works.
Dropping the tank is probably a good idea. Another option might be to drill the screws all the way out. Then you can go take out your sending unit and shake the can a few times to get the old screws themselves.
While you're at it, Eastwood sells a handy little kit to coat the inside of your tank. Chances are good that if your sending unit is rusted up, the inside of the tank is in need of some TLC as well.
Be smart.

 

if you don't mind, i would like to come over to your house and maybe you could show me how you weld a crack or a pinhole on a tank full of gas. i was just wondering don't people put spark plugs in tail pipe to make flame come out?

 

While some of this sounds fun and entertaining I'll 2nd the Kroil option. I've used lots of different methods but after using Kroil I don't buy anything else. Give it a shot before going on to more dangerous methods.
Good luck

 

I had a rusty screw once... but I digress.

 

Any chance you can access the screw from the inside of tank through the filler tube hole with vice grips?

I'm all for NOT doing anything that risks life or limb.

WOOB...please pm me "the rest of the story"

Larry

 

thanks for all the ideas. i,ll let you what happens....