Sandblast Fuel Tank?

[MASTERBrian]

Trying to insure my tank is ready for some sealer, but I still have a few areas, I'm unsure of. Someone mentioned trying to blast the rust out, which in passing sounded like a good idea....

Issue is, my experience has been that when sand blasting a lot of static is sometimes built up and thus it worries me. Am I thinking correctly and thus wise NOT to blast it without experience in doing so, or am I over thinking? I suppose it could be grounded but I really don't want to take any chances.

[geezer#99]

Blasting inside or outside?
Inside needs to be cleaned with steam.
Outside could be bead blasted with something other than sand.

[Dead Parrot]

If the inside has enough rust that you think it needs sandblasting, time for a new tank. Even if you can get all the rust out, the tank will have a lot of thin spots where the rust used to be. And if the rust is bad enough, you might wind up with a sieve.

Compare the cost of cleaning, sandblasting, and sealing vs the cost of a new tank.

And you are correct to be worried about fumes in a used tank exploding.

[MASTERBrian]

Originally Posted by Dead Parrot

If the inside has enough rust that you think it needs sandblasting, time for a new tank. Even if you can get all the rust out, the tank will have a lot of thin spots where the rust used to be. And if the rust is bad enough, you might wind up with a sieve.

Compare the cost of cleaning, sandblasting, and sealing vs the cost of a new tank.

And you are correct to be worried about fumes in a used tank exploding.

I had taken it to a place that cleans tanks and they did use steam to do as much as they could, BUT they ran into a 'baffle' and thus couldn't get it as well as they said they hoped to. They said if I had the fill nozzle removed, it was soldered in place, they could reach the 'other' side. Not really thinking about, and I know some tanks have baffles, I took their advice and had a welding shop remove the fill nozzle. At that point I realized the 'baffle' was just the indentation where the spare tire fits up next to the tank.

At this point, I lost a bit of confidence in the cleaning place and have somewhat decided to try to see what I can come up with. POR-15 swears that with their degreaser, rust neutralizer and sealer even a rusty pitted tank can be salvaged. That said, I have noticed no pin holes and the outside and inside looks pretty good. The issue is just that there was about 10gallons of gas sitting in this tank for the last 15yrs. The way I see it, the tank shop cleaned it about 75% with steam, then the welder had to do something to keep from blowing up. I've cleaned it several times with gallons and gallons of high pressure water and several times with degreaser stuff. Last night I tried to let treat it with the rust neutralizer and it's looking probably 75% good. Lots of very clean metal, but still a few areas, I'm not sure about. Maybe I'll try degreaser again and then more rust neutralizer. I'll forgo the blasting, because I like to remain alive and in one piece and that worries me. Yes, I'm talking inside. Outside, I'm not worried about, I think it's close to ready for paint there.

Any harm in running another larger filter somewhere on the frame rail to try to catch anything large that come through? I'll have a new pickup assembly with new screen, so maybe not needed...

[MASTERBrian]

Here a picture, not as bad as it looked earlier. Must be drying....

[Ironangel]

I've restored many vintage bike tanks, with the amount of of money and labor involved to line a 20 gallon tank with Por-15 you'd money and time ahead to replace that tank. With that said, I saved a 10 gallon 1955 Siegler Oil Heater tank about 7 years ago with fiberglass. After cleaning the tank I held it up to the light and there were so many pin holes that it resembled stars in a night sky. I just simply wrapped the tank using fiberglass cloth and resin and it's still drip free and dry as a bone today. I've used it to heat my shop for 7 years now using diesel fuel, kerosene, among concoctions of mineral spirits, motor oil, and old gasoline. If you go with the Por-15 do not take any short cuts and follow the instructions to the letter! Make sure product you do use is ethanol compatible because many are not and will deteriorate with various solvents. "Just Sayin"

[TJ's Chevy]

Time for a new tank.

[MASTERBrian]

Originally Posted by Ironangel

I've restored many vintage bike tanks, with the amount of of money and labor involved to line a 20 gallon tank with Por-15 you'd money and time ahead to replace that tank. With that said, I saved a 10 gallon 1955 Siegler Oil Heater tank about 7 years ago with fiberglass. After cleaning the tank I held it up to the light and there were so many pin holes that it resembled stars in a night sky. I just simply wrapped the tank using fiberglass cloth and resin and it's still drip free and dry as a bone today. I've used it to heat my shop for 7 years now using diesel fuel, kerosene, among concoctions of mineral spirits, motor oil, and old gasoline. If you go with the Por-15 do not take any short cuts and follow the instructions to the letter! Make sure product you do use is ethanol compatible because many are not and will deteriorate with various solvents. "Just Sayin"

My understanding is the Por-15 sealer is Ethanol Compatible, so should be good there. As far as shortcuts, I'm not ordering the entire kit, just the sealer mainly because I had a complete bottle of their degreaser (kit calls for 2 bottles), I dumped the one in AFTER a steam clean, AFTER a soak in a cleaner water mix AFTER the welder did whatever he did to prep it for work. If that tank isn't degreased, I don't know what tank would be. I then dumped in a good amount of an etcher, which again is another brand that I bought a gallon of from Home Depot. I'll check on it again in a few hours and see how it looks, but am considering running some more degreaser, just to double check. Then some more of the acid etcher and then check it again tomorrow. My sealer won't be here until later tonight, but it's a cool day, so I prefer to wait to do that until it's sunny out again, so I can let it bake in the sun a bit after I do it.

As for saving money on another tank, I'm already $100+ in on this tank and it is not porous and doesn't have any areas that appear to be thin. The other thing is, I'd love to be able to get a spot to store my spare back up under the truck and I can't buy another tank that'll allow that. If it held gas for 15yrs in a field, there aren't any leaks....just want to keep it that way!!

The welding shop wants $600ish to build a tank and all aftermarket tanks I've seen are well over the $200 mark. If I'm missing something or if it appears I'm cutting corners I'm open to input on that.... Feels like I'm going overboard to insure I get a good result. I think, minus fuel filler, I'm only out $100-150 at max and stuff like the cleaner/degreaser and the etch, I've been using elsewhere so that's sort of in material cost but I've figured it into that number.

[68gmsee]

Just as an fyi.

You don't mention year/model of your truck but some of the Spectra fuel tanks are very reasonably priced and probably the best quality and fit for our old trucks. They used to be made in Canada and probably still are. I bought one for my 68 about 15 years ago for about $170. You truck may be cheaper.

[MASTERBrian]

Originally Posted by 68gmsee

Just as an fyi.

You don't mention year/model of your truck but some of the Spectra fuel tanks are very reasonably priced and probably the best quality and fit for our old trucks. They used to be made in Canada and probably still are. I bought one for my 68 about 15 years ago for about $170. You truck may be cheaper.

1960 suburban. Nothing easy to find that is direct fit.

[Captainfab]

If that was my tank I would buy several gallons of vinegar and dump in there and leave it for a couple days. Then pressure wash/steam clean it and the rust should be gone. Don't forget to have the filler neck resoldered prior to sealing the tank.

[MASTERBrian]

Originally Posted by Captainfab

If that was my tank I would buy several gallons of vinegar and dump in there and leave it for a couple days. Then pressure wash/steam clean it and the rust should be gone. Don't forget to have the filler neck resoldered prior to sealing the tank.

I've got another batch of the acid in there tonight. Tomorrow when I dump it I'll see what it looks like and try the vinegar approach. Another thing I've heard is livestock molasses mixed with water and leave for a weak, but I can't seem to find out.

Will a carwash work for the final clean? I've been using my well water, about 35 gallons per minute, with a small nozzle. It works pretty darn good.

I'll have it soldered first, the welder said bring it after sealed, but I think I'll take it to him first.

['63GENIII]

Originally Posted by MASTERBrian

I've got another batch of the acid in there tonight. Tomorrow when I dump it I'll see what it looks like and try the vinegar approach. Another thing I've heard is livestock molasses mixed with water and leave for a weak, but I can't seem to find out.

Will a carwash work for the final clean? I've been using my well water, about 35 gallons per minute, with a small nozzle. It works pretty darn good.

I'll have it soldered first, the welder said bring it after sealed, but I think I'll take it to him first.

Not a plug for the product or anything but Evaporust works really well. Its kinda pricey (20 - 25$) per gallon but it works really well, is reusable and is amazing at the rust it can take off. It says its non toxic, doesnt smell funny and has left everything that Ive used it on looking new. My only issue is that Ive had to use soap and water (preferably Dawn - the old blue stuff) to get the dissolved rust which turns into a black film off of the parts. Ive painted several parts after using it and the paint sticks to it like new metal.

For tank coatings, Ive used motorcycle tank sealers with good success. Ill try to find the name of the sealer.

[Ironangel]

Originally Posted by '63GENIII

Not a plug for the product or anything but Evaporust works really well. Its kinda pricey (20 - 25$) per gallon but it works really well, is reusable and is amazing at the rust it can take off. It says its non toxic, doesnt smell funny and has left everything that Ive used it on looking new. My only issue is that Ive had to use soap and water (preferably Dawn - the old blue stuff) to get the dissolved rust which turns into a black film off of the parts. Ive painted several parts after using it and the paint sticks to it like new metal.

For tank coatings, Ive used motorcycle tank sealers with good success. Ill try to find the name of the sealer.

Kreem is what alot of people use to seal bike tanks. https://www.amazon.com/KREEM-Gas-Tan.../dp/B00IKKQ2U4 Maybe the new formulas have been improved but in my experience once the tanks preliminary galvanized coating is compromised nothing will work for long. Nothing wrong with acid cleaning, steam cleaning, or adding an aggregate such as chain, nuts and bolts, penny's, or what ever to knock the loose stuff free. But before using any tank liners I would simply spray the interior of the tank with WD-40 immediately after drying with a hair dryer or heat gun. The drying process would follow an acid wash simple "CLR". Once the tank is clean, spray it thoroughly with WD-40 and fill it with gasoline ASAP to curtail the rusting process. I could go into alot of chemistry and experience but the fact remains, the more crap you put in a tank, the more crap there is to clog filters, pumps and carbs. The only permanent fix is a new tank. Plastic tanks dont corrode. If your metallic tank has an electrical sending unit the best rust preventative is a well grounded tank! If your welder wants to weld or solder on your tank "after" the sealer is applied, fire him! In short, forgo the tank liner and just use the tank as is, I've seen alot worse. Go with it and save your money for a new tank in the future. Do not use Phosphoric Acid in a fuel tank, the Iron Phosphate will kill screens, pumps and carbs. Heres a read on Kreem... https://kzrider.com/forum/6-paint-a-...reem-from-tank. The internet is full of past experiences such as yours, read up and stock up on inline filters...

[StingRay]

Evaporust, molasses/water and citric acid all remove rust through selective chelation. There are other chelators as well. Evaporust is fast and expensive. They don't attack the material itself. Phosphoric acid is also a good rust remover that is not hard on the steel as well.

[MASTERBrian]

Originally Posted by Captainfab

If that was my tank I would buy several gallons of vinegar and dump in there and leave it for a couple days. Then pressure wash/steam clean it and the rust should be gone. Don't forget to have the filler neck resoldered prior to sealing the tank.

Welder can't get solder it until Monday, so I guess I'll wash out my metal prep this evening and if still have some rust then I'll go buy vinegar....how many gallons is enough for a 15 gallon tank?

***I just looked something up and it says to possibly add salt to the vinegar to help as well, creates a different reaction. Sounded like a gallon or two mixed with 1-1/2-3cups of salt is enough. Then they say to neutralize with baking soda/water mix, then the WD-40 and fill with fuel. This adds to the questions....
1) Is the vinegar followed by baking soda mix ok IF I decide to seal it with the POR-15 or do I skip this step and seal it?
2) If I decide not to seal it with POR-15, is the WD-40 ok to apply before going in to have neck soldered back on?

I'll post updated pictures once I rinse it back out.

[Captainfab]

I have never used vinegar in a gas tank. I do use it quite frequently on the products that I fabricate to remove the mill scale. Then I neutralize with a water and baking soda mix and then rinse with clean water. You will need enough vinegar to submerge all of the rust in the tank. I would also forego any tank sealer and just coat with some sort of light oil.

[Ironangel]

Do not use WD-40 or any other light oil before soldering or before using the Por-15. Once that neck is soldered (depending on how much crap enters the tank from the soldering process) then use either the Por-15 or the light oil. The idea for the use of the oil is to stop the rusting process that immediately begins when the clean steel is exposed to air. (oxygen)...Thats why in days of old when gasoline was really gasoline and you stored a bike or a boat, "or a tractor" for any length of time you fill them. "Simple science" once upon a time until moonshine was added to gasoline to please the tree huggers...