Rust Inside Gas Tank -- Help (Total Noob First Build/Bike)
- Thread starter reborn291
- Start date
jacksondee
Active Member
maxDTM said:
Very cool, thanks. Lets hope the 10 min of Muriatic doesn't eat the cork...
I would not use muriatic acid on steel. It's hydrochloric acid. It will deposit Cl ions into the surface and contribute to rusting forever. You will make it worse. Use phosphoric acid or citric acid.jacksondee said:
jacksondee
Active Member
deviant said:
How much phosphoric? My tank is about 4.5 gallons.
I use vinegar to get all the fuel out first. I don't think it's necessary, it just like to have it clean before I start the etch. Pour a half gallon of vinegar in the tank and swish it around a lot, then pour it out. You can get a gallon of phosphoric acid from Home Depot, Lowe's or somewhere like that. It's usually labeled Phosphoric etch and prep or something like that. Pour a quart to 1/3 gallon into the tank and swish it around really good so it completely wets the inside. You can leave the quart in the tank or pour it out and reuse the etch again. I usually pour it into a plastic bowl that I'll use for rusty nuts and bolts or other parts. I keep a separate batch of dirty acid and a batch of clean, unused acid. If you leave the quart of acid in the tank, let it sit for an hour or so, swish it again and pour it out. Typically, the etch has done its job when it starts to dry and turn white. You can then rinse it with water. Let the tank dry out and check for how well it worked. If it needs another treatment, pour another quart to 1/3 gallon in the tank and do it all again. If you want to speed up the water drying, you can pour isopropyl alcohol into the tank, swish it around and dump it out. You can also use a hair dryer or heat gun to encourage evaporation. If you fill the tank with etch, it will speed up the process. You just have a lot of etch to deal with later.
jacksondee
Active Member
thanks. have a bunch of paint prep on side panels and fenders I can do while i let the acid sit in the tank tomorrow. I'm about 2/3 done with cleaning and modding the carb.. its going to be a good summer..
jacksondee
Active Member
Deviant your technique with the Phosphoric worked pretty perfectly. I think I might need one more dose of it. I'm going to let it dry a bit and take a closer look. But even without a flashlight I can tell its much much cleaner in there. I am getting antsy to put some primer on this freaking tank so I can be done with bodywork/paint prep!
