Originally Posted by Flat Ernie

Tanks are relatively inexpensive for our old trucks. However, if you want to tackle it yourself, it's pretty straight-forward. Here's my method:

1 - Rinse & flush with water to get larger particles out.

2 - Put about 1 gallon of denatured alcohol, along with a handful of roofing nails, nuts & bolts, or something else you can use to shake around - seal up the openings well with duct tape.

3 - Shake, rattle, & roll. Be sure to shake and slosh with all 6 sides at the 'bottom' of however you hold it. I've even heard of folks strapping it to a tractor tire and driving around the field for a while. You can't shake it enough. When you're tired. Shake it some more.

4 - Did I mention to shake it?

5 - Open it up and rattle all the junk out. Rinse with denatured alcohol until it's clean.

6 - Pour in about 1/2 gallon of muriatic acid. Be very careful with this step as it will burn you, etch concrete, and create fumes you don't really want to inhale - do it outside. Carefully slosh the acid around all 6 surfaces of the tank - be sure to get the top well. This step removes the rust.

7 - Rinse with water.

8 - Rinse with alcohol.

9 - Put about a 1/2 gallon of phosphoric acid in and slosh it around carefully. Same precautions as muriatic acid, but it's not nearly as caustic - still, you don't want it on your, concrete, or your clothes. When done and certain all 6 sides are coated, dump it out and let it dry overnight.

10 - The next day, rinse with water.

11 - Rinse with alcohol.

12 - Reinstall.

13 - Forget about your tank and move on to the next project....

Originally Posted by bhalemail

I used the POR-15 kit but did most of what you mentioned below. I have an electric cement mixer and tack welded a scrap piece of flat bar to it, drilled a couple holes to match up to the gas tank mounting holes and fastened it to the mixer. added a gallon or so of gravel from the driveway, duct taped the holes and turned it on for about 4 hours. no rust after that! then rinsed with water several times and did the POR-15 kit. Worked great. Did this for my 50 and 52 tanks. Probably would've made sense to buy new tanks but it was fun.