I have a black pegasas kitchen sink and it has a brown film on the sides of the sink. how do i clean this and get it off.

a moth

Remove tubular pipes under sink and clean out disposal.
Copy following links for steps for clogged disposal:
http://waterheatertimer.org/How-to-repair-and-install-Garbage-disposal.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

If the hot water side of the kitchen faucet will not shut off valve under the sink, dirt,rust,and/or scale could have been forced into the faucet along with the possibility of flux and some old rubber washer from the old valve. You will need to take the kitchen sink faucet apart and most likely only need to clean it out, looking for any little black,brown, or white pieces to remove. If cleaning does not work because you cannot get into an area of the cartridge, you will need to replace the carteidge and or rubber seals. Make sure to clean out the aerator on the end of the spout when completed also.

You can use Kohler cast iron kitchen sink cleaner, available on line, Jacuzzi recommends warm water, mild non-abrasive liquid soap for everyday cleaning and Barkeepers Friend or Zud for tougher stains. No Abrasives whatsoever. like Comet etc.

A Master Collection designer Thermocast cast acrylic double bowl kitchen sink with a rich high gloss finish that is easy to clean with non-abrasive cleaners.

1. 1

   Put on rubber gloves. Spray the sink with a nonabrasive commercial kitchen cleaner, covering all surfaces of the sink with the spray.
   

2. 2

   Dampen a sponge in warm water. Wipe the sponge over the sink, scrubbing at any visible dirt.
   

3. 3

   Rinse the sink with warm water and then dry it with a clean towel.
   

4. 4

   Fill the sink with warm water and add 1 tsp. of chlorine bleach per gallon of water, once a month. This will sanitize the sink, and is recommended by Thermocast. Let the bleach-water mixture remain in the sink for 15 minutes, then drain the sink. Rinse.
   

5. 5

   Apply liquid automotive polish to a clean, soft cloth. Wipe the cloth over the sink to remove any scratches that may have occurred. Buff the sink using a circular motion. Rinse.
   

Abrasive cleaners may scratch Thermocast sink surfaces--using abrasive cleaners may also void the warranty.

It is probably only calcium deposits from hard water. 'Lime Away' will remove such deposits easily.
Black may be beautiful in the showroom or on people but not very practical for household stuff; we will never buy black kitchen appliances again.

If you have changed the drum then probably your fixing film was torn. Check if the black streaks on paper is erasable (not fixed on the paper). Check also for signs of film (gray on one side and brown on the other very thin plastic-like material) falling out from your fixing assembly (if you open the left side cover with caution sign the hot portion area).

Scouring powders or cleansers contain abrasives commonly used to clean and remove stubborn stains that are slow to respond to chemical action alone.

However, use of an abrasive cleaner may scratch and damage smooth finishes such as porcelain, fiberglass or enamel making it even more difficult to clean the surface in the future.

New kitchen and bathroom fixtures do not require a scouring cleanser to clean them of soap films and body oils. Dissolving soil by soaking with the correct non-abrasive cleaner (especially a foaming type that sticks to the surface) then wiping and rinsing usually does the job.
When cleaning older, abused fixtures, choose the mildest abrasive cleaner available such as a Soft Scrub -type product or baking soda, and apply just enough that, with light pressure, the embedded soils are loosened and may be rinsed away.

Using soft scrub or some brand similar is the best thing to use. Manufacturers reccomend only soap and water, but soft scrub is best. Be sure to never use abrasives on any fixture, it will scratch and void warranty
Kohler makes a cleaning agent for cast iron sinks, if this is what you have.

hope this helps