I have a 1950's formica table that's been exposed light for years and had a discoloration. I discovered that lemon juice and sunlight seemed to remove the stain. I got the table completely back to original look and then had it in the sun and all of the staining came back. Does anyone have an idea about what's going on or how to clean this table so it says clean?
This link provides some ways to clean the stain, if you can't find a solution elsewhere, maybe it's worth a try. 5 Ways to Remove Stains from Formica
First, if it's due to age or natural discoloration, it's suggested that you just replace your countertop.
If you are dealing with actual stains, you can soak it with soap water or detergent.
For stubborn stains on your Formica, blend a pasty mix of water and your choice of powdered cleanser. Depending on the size of your stain, you may not need more than a few tablespoons of water. Once you have your paste, smear it out over the stain, covering it completely. Let it fully dry out and crust over, and then remove it with a warm wet washcloth, being careful to not let the abrasive nature of the dried paste scratch the surface. A quick wash down with some soap and water and you should be stain-free.
An alternative paste would be using baking soda:
[U]se baking soda and soda water, instead. Brush the paste on the stain, and cover it with some plastic wrap. This time, you're going to need to leave it alone for a full 24 hours for best results. Wipe the surface clean with warm water and a washcloth the following day and your stain should be a thing of the past.
If it's some very stubborn stain like coffee, hair dye, watermarks, nail polish remover can be used:
[B]rush some acetone nail polish remover onto the stain with some cotton balls. Before using it on a colored countertop, test it out in a hidden corner and see if it changes the color. If it does, you might want to just live with the stain. If it seems like it will work, though, try it out, and then wash down the counter with some soap and warm water.
With all those said, if you are not able to clean the stain off and you cannot tolerate the stain on there, you should probably just replace your countertop.