Rust removal via chemical means

I tried the electrolysis five gallon bucket battery charger method on a cast water pump housing.
It worked good to a point. I wound up sand blasting it to get bare metal inside of it.

All this has gotten me to thinking about my next hood.
The last one I sand blasted it but that doesn't get into the bottom of the rib channels.
Underneath.
So I was thinking about making a tray and laying the hood in it.
Then pressure washing the thing.
Splish splash taking a bath.
Now, does a five gallon bucket of Evapo-rust need to be diluted?
That would make it very cost effective.
In a search I found the following.
Someone suggest the very thing.


Will the real Evapo-rust please stand up?
Hi again
I would like to add a few comments to last evening's post. First someone mentioned a salt and vinegar. One needs to realize that these are both corrosive, just look at what that does to an automobile in the regions where we get snow. You can never neutralize these enough to be safe. However that mixture will make a great weed killer. I believe 1 cup salt to a quart of vinegar.
Further it was mentioned that yo should use Evapo-Rust sparingly, small container to fit the part. This too is wrong. A small container will saturate very quickly and the product will quit working much too soon. I use a 5 gal. pail all the time and I probably clean a thousand parts in it over a period of a year. I am restoring a 56 Studebaker, and every small part that will fit into the pail gets cleaned. If the piece is too long it gets one end done then turned over. Large parts such as a door off the car goes flat into a tray made from 2x6 and plywood with a heavy plastic sheet in it. Door bottoms alone can be done on the car using a trough such as a piece of gutter strung up around the door bottom. Flat surfaces vertical or horizontal can be cleaned if it is only surface rust by soaking an orange chamois, soaking it with product and then laying it on the rusted area covered with a sheet of plastic to slow down the evaporation time. Rinsing it off with water will immediately neutralize it and remove it, leaving undamaged virgin metal behind. No further neutralizing required. Machinery such as lathe parts and beds can be de-rusted in this same manner. This product is entirely biodegradable and requires no special handling unless contaminants have been introduced so disposable is very simple.
Then there was the question about watering down the concentrate. This concentrate must be mixed 1 - 5 with water or it will not work. Less won't work nor will more. The reason for shipping concentrate instead of mix is that we don't want to pay $200 or $399 to ship a drum full of water. Just a few drums worth of concentrate at six drums a piece in mixed form would soon fill a transport trailer. See the logic in that?
We ourselves have numerous customers who use our product in their manufacturing process. For instance West Cast Industries makes manifolds for several car companies. When these come out of their molds they flash rust very quickly and sit for some time before machining to normalize the castings. These are them dipped in Evapo-Rust for 1/2 hour and them machined when drip dried. We have a customer in tn the east coast that reconditions rail cars and all the brake lines have to be cleaned or replaced. Cleaning would require a product that when flushed of/out would not leave a residue that could damage the rebuilt cylinders and valves. This was the only product that worked. We have a customer called Auto-Tube who manufactures all those steel tubes you see under the hood of your car. Being new steel it quickly gets a film of rust when the humid summer weather comes. Again these tubes must be clean before being shipped to the car companies. Chrysler uses this on warranty work on door bottoms using the method described earlier. This has saved them from sandblasting and repainting the entire door. This product cleans the rust away without harming the paint on the outside of the door thus saving them millions on repairs. Our product does the job. We could go on and on but I think that is sufficient information for now. Let me say this product is probably the safest product you can use and requires no special handling and disposal.