Easy way to clean out the gas tank

[nyncompute]

I had the same issue. I mulled over the options and went to the junk yard and was lucky enough to find a clean 72 tank. I popped the sender off 3 trucks to find a good one. $50 bucks later .. problem solved.
Below you see some of the horrors that awaited me all though the fuel system(that wasn't even half of it). If I hadn't found the good replacement I would have bought a new unit. If you can scrounge up the Benjamins it might be a good time for a rear tank conversion
That gas tank turner thingy is slick and ingenious, but way over the $149.00 hassle factor price for me.

[Youngbuck7072]

wow, my tank looks pretty clean from the outside, but i really dont want to get a new tank, i guess i will pull it our and see how bad it really is

[Dark Knight]

Another thing I just remembered is lacquer thinner. You can get 5 gallons from CarQuest and dump it in there. Slosh it around and let it sit for a couple of days. It's much safer than acid and works pretty darn well too. I cleaned my Jeep tank that way. Then, just blow it out with compressed air, making sure to be wearing a mask and eye protection.

[72lb4x4]

Originally Posted by nyncompute

I had the same issue. I mulled over the options and went to the junk yard and was lucky enough to find a clean 72 tank. I popped the sender off 3 trucks to find a good one. $50 bucks later .. problem solved.
Below you see some of the horrors that awaited me all though the fuel system(that wasn't even half of it). If I hadn't found the good replacement I would have bought a new unit. If you can scrounge up the Benjamins it might be a good time for a rear tank conversion
That gas tank turner thingy is slick and ingenious, but way over the $149.00 hassle factor price for me.

Even if you get a tank from the scrapyard, it needs to be cleaned. If cleaning it, you might as well coat it.

A 3 step kit from KBS costs $50 or so. There are vids out there demonstrating its use.

There are cleaners such as purple power that will take off the gas based residue in the tanks, and phosphoric acid seems less caustic than muriatic acid.

[Fitz]

Originally Posted by 72lb4x4

There are cleaners such as purple power that will take off the gas based residue in the tanks, and phosphoric acid seems less caustic than muriatic acid.

Phosphoric acid converts iron oxide into ferric phosphate, a hard black crystalline substance. It does not dissolve it so, while I use phosphoric acid to treat bolts...gives them that hard black coating, it does not work well in a tank as those crystals of ferric phosphate can still dislodge and end up in your carb! If you want to use it Caswell Plating sells a gel kit of it. The muriatic acid takes iron oxide into aqueous solution so when you pour the muriatic acid out of your tank you are removing everything from the inside. The residue can be diluted with water and poured out. Muriatic acid is the commercial name for hydrochloric acid---the acid in your stomach! If you dilute it greater than 5 to 1 it's no more toxic or dangerous than your own puke.

Acetone will dissolve the the hydrocarbon coating left from the gasoline and it's additives making either phosphoric acid or muriatic acid more effective but I'll stay with the muriatic as it leaves behind clean bare metal; just as your tank was when it left the factory. If you feel the need to coat it, use Caswell Tank sealer...a 20 gallon tank kit costs 69.00 but this is the only tank sealer that will not detach from the surface like Kreem will and you can put it right over the rust! It's a binary phenol novolac epoxy which will actually deaden the sounds from your tank as well. Available here:

http://www.caswellplating.com/aids/epoxygas.html

[72lb4x4]

My reference for the phosphoric acid is the process used by the KBS product and its commonly used to treat very light rust.

I'm not doubting the effectiveness of muriatic/hydrochloric acid. I was just thinking it might be overkill.

[Youngbuck7072]

so how much of this muratic acid should i mix up? 1 gallon, five?

[Fitz]

Originally Posted by Youngbuck7072

so how much of this muratic acid should i mix up? 1 gallon, five?

1 quart of acid to 1 gallon of water should do it. Just enough to cover a full side when you flop the tank over. Just be sure you pour the acid itto the water, not water into acid. When the acid and water mix it makes makes a bit of heat and can spatter if you pour the water into the acid. This acid does not attack steel like battery acid (sulfuric acid) but don't leave it long...20 minutes a side is probably enough.

[sleepertruck72]

I have a tank I want to clean out also, Would pressure washing at home and then using metal etch inside before coating it be effective ? Or should I stick to muriatic acid before coating ?

[Youngbuck7072]

so i pulled the tank, and it looks really clean. i am NOT going to coat the tank, just clean it out. here is a pic of the inside parts, with the float cleaned up. doesnt look that bad i have to say[IMG][/IMG]

[Youngbuck7072]

Question, when i put the muratic acid in, when i turn the tank, what should i put over the two holes to keep it from pouring out?

[Fitz]

Originally Posted by Youngbuck7072

Question, when i put the muratic acid in, when i turn the tank, what should i put over the two holes to keep it from pouring out?

I used duct tape, but even plastic package wrapping tape works too if the outside is clean enough to get it to stick.

[Youngbuck7072]

okay, thanks man

[68shortstep]

Most swimming pool supply stores & also building supply places carry muriatic acid, which is commonly used for cleaning & lime (water hardness scale) removal. Swimming pool companies wash pool walls with muriatic before they repaint them in the Springtime. (A pool is a big hole in the ground you try to fill by dumping money into).

Building supply stores also call muriatic acid by the name "brick bath" & sell it ready-to-use strentgh in 5 gallon jugs, which is used to get leftover mortar smears off the freshly-laid brick on brick house walls & commercial buildings.

I've forgotten my basic chemistry (almost 45 years ago), but I believe muriatic acid is 5 % strength in water, made from concentrated hydrochloric acid. Google it !!!!!!

Whoever it was above that said that muriatic acid's worse about burning / eating your hide off than battery acid (which much more concentrated sulfuric acid) is NOT correct. Most brick mason's apprentice helpers start out carrying bricks & by washing the laid bricks with brick bath. Toughens their hands & you find out if they're really serious or not about working. It'll eat on you, but not like battery acid will .....

The above answer of "add the acid to water & NOT water to the acid" is VERY correct. Dumping water into acid to dilute it can literally cause instantaneous boiling of the water, & cause it to blow right up into your face as acid & steam. Add the acid to the water SLOWWWWWWWLY.

Any acid is pretty unforgiving, & loss of eyesight is forever .................

[trev1]

Glad someone asked this question.... I have a tank to clean out, before we install it. I think I will build the rack suggested earlier in this Thread and use the Muratic Acid solution to clean it. Should be easy to do. Then I will have a way to rotate the tank when it is time to coat the inside. Besides the tank rack/rotator looks cool. ABSOLUTELY FANTASTIC Tank holder rig.

Thanks

Trev1

[nasqar]

Originally Posted by Fitz

Phosphoric acid converts iron oxide into ferric phosphate, a hard black crystalline substance. It does not dissolve it so, while I use phosphoric acid to treat bolts...gives them that hard black coating, it does not work well in a tank as those crystals of ferric phosphate can still dislodge and end up in your carb! If you want to use it Caswell Plating sells a gel kit of it. The muriatic acid takes iron oxide into aqueous solution so when you pour the muriatic acid out of your tank you are removing everything from the inside. The residue can be diluted with water and poured out. Muriatic acid is the commercial name for hydrochloric acid---the acid in your stomach! If you dilute it greater than 5 to 1 it's no more toxic or dangerous than your own puke.

Acetone will dissolve the the hydrocarbon coating left from the gasoline and it's additives making either phosphoric acid or muriatic acid more effective but I'll stay with the muriatic as it leaves behind clean bare metal; just as your tank was when it left the factory. If you feel the need to coat it, use Caswell Tank sealer...a 20 gallon tank kit costs 69.00 but this is the only tank sealer that will not detach from the surface like Kreem will and you can put it right over the rust! It's a binary phenol novolac epoxy which will actually deaden the sounds from your tank as well. Available here:

http://www.caswellplating.com/aids/epoxygas.html

FITZ....what in tarnation do you do for a living? A chemist/pharmacist? I havent heard talk like this since engineering school!

[72lb4x4]

I coated the tank last night and disassembled the tank rotisserie tonight. It worked well and was easier than rolling the tank around the yard.

[Youngbuck7072]

so guys, i got my tank cleaned out....just as i suspected, it wasnt that dirty, and i put more acid in than the recomended amount[IMG][/IMG]owell. so, i got all the water drained out of the tank, now what kind of alcohol do i put in it? rubbing? and how much? how long should i wait? will some pour out or will it all dry up? any answers would be great. thanks for the help so far guys

[Fitz]

Originally Posted by nasqar

FITZ....what in tarnation do you do for a living? A chemist/pharmacist? I havent heard talk like this since engineering school!

Sorry. I am an Engineering Director for Raytheon Missile Systems in Tucson.

I play with trucks on the weekend just to keep grease under my fingernails!

[nasqar]

Originally Posted by Fitz

Sorry. I am an Engineering Director for Raytheon Missile Systems in Tucson.

I play with trucks on the weekend just to keep grease under my fingernails!

Very nice......remind me not to post my GPS location if you become upset!!!

[TheWhiteElephant]

To add a little to the mix here, I do believe the rust issue is a bit overblown, ESPECIALLY on daily drivers. I had a K5 that sat pretty much on empty for 2+ years with just an occasional start. I removed the tank to clean out the sludge and assess the "rust", and it was clean as a whistle. Humidity is extremely high here pretty much year round.

I just removed the tank on my '73 from South Dakota that sat for long periods of time, and I was surprised at how clean the tank looks on the inside. Just some minor debris.

From the research that I've done, as long as the vehicle is used regularly--meaning regular fill-ups on a daily driver, there shouldn't be a rust issue because there won't be much (if any) moisture build-up on a full tank. The tanks are sealed very well. Of course this is different from state to state, but I've personally seen tanks that back this up from cold South Dakota to hot South Texas.

Just my .02.

[swamp rat]

Best thing you can do to prevent rust in the tank is keep your tank full, the least amount of metal surface area the less it will have the oppritunity to condensate and rust.

[68GMCCustom]

I've got a nice '68 tank I need to find a new home for!

[TheWhiteElephant]

Originally Posted by swamp rat

best thing you can do to prevent rust in the tank is keep your tank full, the least amount of metal surface area the less it will have the oppritunity to condensate and rust.

Exactly!

[eagleuh1]

I cleaned out my old one and drove on it for 6 months. No problems but occasionally got the laquer in my fuel filters. I had cleaned it before doing my LS install. No leaks, worked great. Took it out to do body work and install sound deadener. Sat next to my truck in garage for 2 months. With gas in it. Openings sealed with plumbing plugs and vacuum line plugs. Put it back in after draining old gas, flushing with garden hose and drying with alcohol for 2 days in the sun. Drove it for 2 days and started leaking at the bottom seam bad. Dissolved quite a bit of sound deadener. Luckily I ordered 100 sq. ft. I decided to go with a new tank since I was supposed to be in Pheonix in 2 days. NAPA sells a Red.. tank seal.Takes 2 quarts at $50 each. But it takes at least 2 days to do it right. And tank needs cleaned very well to use it. And dried completely. I just bought a new tank.