I have the fuel tank removed and it had ran vegetable oil in the past. Inside doesn’t look that bad but some rust. What’s the best thing to let soak or any tips and tricks removing rust? Thanks
Some solvent and a bunch of nuts and bolts thrown in it and shaken as violently as you can. Not sure the shape of the tank but have seen where someone clamped a tank on their tractor wheel and drove around for a few minutes.
I use citric acid as a rust removing chemical, with about a 5% to 8% solution. It's safe to use and works well. Some people claim molasses works for them. If you can't find citric acid, you can gather up rotten citrus fruit, throw it in a barrel and fill it with water and let it soak for 3 weeks. Decant the liquid out of the barrel, and you have a citric acid solution! The only downside with this method - it doesn't exactly smell like roses! - more like rotten fruit!
To add to Welder Dave's suggestion, I've heard of using a short piece of chain, say a couple of feet give or take of 5/16 or 3/8 in size and put that in other than nuts and bolts (they say it's easier to retrieve) and roll the tank around for a while. I also what to say there's an acid us3d to remove rust...Muriatic acid? However it is a corrosive so you need to treat it with respect, also be sure it's well flushed so as not to allow it to get into the fuel system. It's used in the swimming pool business so it can be found anywhere they sell those products I would assume.