Symptoms
- Orange or brown rust visible on the disposal exterior
- Rust around the sink flange or mounting ring
- Flaking metal near the bottom of the unit
- Unit is many years old
Likely causes
- CommonAge and prolonged moisture exposureStandard disposal housings are steel and will eventually rust, especially in humid cabinets.
- CommonChronic minor leaks feeding the corrosionA slow leak keeps metal wet and speeds up rusting.
- PossibleStainless-steel-lined unit with only the outer shell rustingCosmetic rust on the shell doesn't always mean the grind chamber is affected.
What to do
- Wipe the unit dry and inspect closely to see whether rust is surface-level on the housing or has reached the grind chamber or seams.
- Check for any active dripping near the rusted areas.
- If rust is only cosmetic on the outer shell and there's no leak, it can usually be left alone or lightly wiped and monitored.
- If rust has created pitting, holes, or is near the flange or bottom seam, treat it as a sign the unit is failing.
- Plan for replacement rather than attempting to patch or seal a rusted-through disposal housing.
- When replacing, consider a model with a stainless steel grind chamber for better rust resistance going forward.
Tools and parts
- Flashlight
- Rag
Stainless steel grind chamber garbage disposalSearch: “garbage disposal stainless steel grind chamber”
When to call a pro
Once rust reaches the grind chamber, drain seam, or mounting area, replacement is safer and more cost-effective than repair.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.