I was thinking about making a container big enough to hold a fender and fill with Vinegar to get ride of all the rust. I was wondering if anyone has tried to do anything like that before and how well it works.
That much Vinegar is going to get pricy.You might be better off using the citrus acid powder price wise. Build a wooden frame big enough to hold the fender.Line it with heavy plastic like a painters drop cloth.As long as your careful not to poke a hole it will work fine.
As above, citric acid works great, and you can buy it in powdered form online. Make a box, lined with plastic, or on old kiddy pool, and you're off, or the rust is off. I agitate the solution when I do mine, but I usually am doing smaller parts in a tub, and it's easy to do.
Vinegar eats good metal and rust simultaneiously. It works OK on heavy hard parts, but is too aggressive for sheetmetal. I have a damaged hood as a reminder not to do this. I've never tried citric acid. If you go that route, do some research on the process; it's my understanding you need to neutralize the acid when done. The safest and simplest method is molasses. (Unfortunately it's also the slowest.) You can buy cheap feed-grade molasses in bulk from a feed store, then mix it 8:1 with water (some guys stretch this to 10:1). Your fender can sit in that solution for months without damage to the metal. I usally allow 2 weeks to a month. When you pull your fender out, it may look like nothing happened, but when you blast it with a garden hose, the rust will wash away. If there's still significant rust, put it back in the solution for a while. The one drawback is that the molasses solution will eventually start to stink, and you'll need to get rid of it. If you've got a big property, no problem--its safe to dump on the ground. I live on a small city lot, so I try to time the dumping of molasses to occur in winter, so the rains can wash it in. I dumped it once in summer, and that area of the yard stunk for a month. The neighbors thought I was brewing beer! I told them I was experimenting with a special garden fertilizer (which is technically true).
Citric acid works good, and is relatively cheap to buy. Any acid should have a neutralizing, baking soda works good for this.
I bought one of those totes that was used for fertilizer/ag use. Washed it out well and used citric acid in it. If I can get a rusted part in the vat, I will put it in there. Give it 2 or 3 days and it will be rust free without damaging the metal. Just be sure to be ready to coat it with something, because it flash rusts almost instantly.
I vote black strap molasses, eats only rust so no worry about metal decay. Also just hose off with high pressure and go. No neutralizing necessary and just pour out when done. Totally bio degradable. Mix it stronger, around 6 or 5 to 1 and it works A little faster.
I have used molasses a few times, it works ok for the price. One more thing, it works better in warm temps, so doing it now in a northern climate is out, and it stinks too much to do it inside. Citric acid does not stink, and can be done inside where its warm
I met a gent who built a big tank to drop doors and wheels into off of his model A, he said he put a cattle water tank heater in it and that it worked awesome. He had heard that the hotter the water the better it worked and he said the cattle tank heater was the easiest and cheapest thing he could think of and that the results were awesome. Considered building a bigger tank to drop my doors and cowl into and if I do I'm going to try the heater trick.
I recently had to de-rust a part that was too big to submerge. I was using Evaporust but this technique would probably work with vinegar as well: I soaked paper towels in the liquid, put them on the surface of the part, and wrapped everything up in Saran Wrap to keep the paper towels from drying out.
I did what Stuart did, take some old towels, soak in vinegar lay on the surface, keep moist for several hours. Let dry overnight. Wire brush the rust residue off the next day. Neutralize with baking soda/water. repeat as necessary. I did this for the surface rust on the top surfaces of my '51 Jag, worked surprisingly well.
Citric acid all the way. I like it because it’s not messy and it’s relatively cheap. I heard good things about molasses, but have never tried it.
I vote for citric acid. I buy food grade powdered citric acid on EBay. Like $15 for 5lbs. I rinse with baking soda to neutralize after a good soak. It eats rust, but leaves paint and doesn’t seem to hurt chrome. I found a 60’s era Corvette shifter which was completely frozen from rust. Threw it in a bucket with citric acid for a week. Pulled it out and rinsed with garden hose and soft brush and it worked like new. Really amazing. Don't spill it on your concrete garage floor or drive, it eats concrete.
Molasses worked great for me. Took a week or so and no smell. I just removed the back of the tank and it all flowed out. Doesn't hurt pot metal, rubber or paint....just attacks rust. I did a write-up on it a couple of years back............ https://www.jalopyjournal.com/forum/threads/rust-removal-the-miracle-of-molasses.557996/
Molasses works well, see - evintho - post above. RUST-BAN 392 is to protect against the evils of rust.
Is dipping something like the bottom of a door where it gets into the pinch weld/seam a problem? What do you do to neutralize the citric acid, or effectively clean out the molasses?
I have used molasses, but prefer citric acid. It’s just easier to mix and doesn’t ferment like molasses I also have concerns that the molasses may attract critters, while the citric acid may not.
I use dilute Muriatic acid. Neutralize with baking soda or lye solution then wash thoroughly with water. Blow it dry with the air hose. A pint of acid in 10 gallons of water will do the job.
I really don’t measure out the citric acid amount nor the baking soda amount for rinsing. I just pour some in a ice cream bucket of water, stir and rinse the parts with it. Pretty unscientific I know. Then rinse really well with plain water and dry quickly and thoroughly.
I think you could do that with molasses. Vinegar would leave an ugly etch line, as I learned the hard way. Do a test with a rusty piece of sheet metal. How to clean it? Blast the hell out of it with a garden hose or pressure washer.
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