To remove powder coating from metal, choose a removal method that suits the coating and the metal underneath. At EZ Home, we use a heated chemical stripping bath, then clean and prepare the exposed metal before applying a new finish.
I used to sandblast every piece. The frustration was how long it took. When we started making batches of custom Milwaukee Fastback knives, spending a few minutes on every handle piece added up quickly.
For one batch of 25 knives, we went from 100–150 minutes of sandblasting to a stripping soak of about 10 minutes for all 50 handle pieces together. Heating the bath, handling the parts, rinsing, drying, and preparing them for new powder coating are additional steps.
The product we use is Nanner Peel Mad Scientist, which we sell through our collaboration with Cherokee Chemical Company. This is the process we use in our shop and the experience behind our results.
What changed with a batch of 25 knives
Each knife has two handle pieces, so a batch of 25 knives means 50 pieces to strip. Sandblasting took us about two to three minutes per piece.
|
Removal method |
Time for 50 handle pieces |
|
Sandblasting one piece at a time |
100-150 minutes |
|
Chemical stripping in one batch |
About 10 minutes of soaking |
That is a difference of 90–140 minutes for the coating-removal stage, or approximately 90–93% less time. The comparison is specific to our parts and stripping conditions; heating, handling, cleanup, and preparation still need to be included when comparing the complete process.
Our bath takes about an hour to heat up. We arrange that warm-up before our 8 a.m. start so the solution is ready when we begin. If you start with a cold bath, include heating time in your own comparison.
For us, the useful change was being able to strip the whole batch together. We still have preparation work afterward, but we are no longer blasting the coating off every handle individually.
Our stripping setup
We have a 3-liter tank, a 10-gallon tank, and a 55-gallon drum. Each has its own heater, and we choose the tank according to the parts we are working on.
My preferred bath temperature is 175°F. For the 10-minute example above, we used the product at full strength, meaning as supplied with no water added at the start.
The current published mixing directions specify one part Nanner Peel Mad Scientist to one part water. One gallon of product plus one gallon of water makes approximately two gallons of working solution. Follow the current label for your setup; our undiluted shop example describes a different concentration.
We have also used the product on wheels, valve covers, coilovers, and license plates. Those examples show the range of projects we have worked on, but the material and construction of each part still need to be checked.
How to remove the coating with a stripping bath
1. Check the metal and the product directions
Identify the metal before putting a part in a chemical bath. The product is intended for aluminum and compatible non-ferrous metals, and its directions also allow some ferrous-metal applications. Magnesium alloys require particular caution because damage can occur. Confirm unfamiliar materials with the supplier.
A wheel, valve cover, or coilover can include different materials and components. Confirm what must be removed or protected before treatment, especially seals, bearings, plastics, and assembled mechanisms. Our experience with a type of part does not establish that every version of that part can be immersed as a complete assembly.
2. Set up ventilation and protection before starting
The biggest mistake I would warn a beginner about is poor ventilation. Plan the work area before heating the bath. Work outdoors with good airflow where suitable, or use ventilation designed to carry vapors away from the work area. Simply circulating air around a tank does not establish that exposure is controlled.
Read the Safety Data Sheet before use. It warns of severe skin burns and eye damage. Wear suitable chemical-resistant gloves, protective clothing, and the specified eye and face protection. Commercial users should assess their need for local exhaust or respiratory protection.
Use a tank and temperature-controlled heating equipment suitable for the chemical and operating temperature. The product directions recommend stainless steel. Follow the equipment instructions for heating, supervision, and shutdown.
3. Prepare and heat the bath
Prepare the solution according to the current directions, and check the bath temperature before loading the parts. My preferred setting is 175°F; the product FAQ gives a recommended operating range of 150–175°F.
Allow for warm-up in your schedule. The approximately one-hour heating time I described is from our setup. Tank size, heater capacity, starting temperature, and the amount of solution affect how long another setup takes to get ready.
4. Submerge the parts and check the coating
Fully submerge the compatible parts being stripped, following the product directions. Our 50 Fastback handle pieces took about 10 minutes in the heated bath. Check the actual coating removal and follow the directions for further soaking if needed.
Coating type, thickness, temperature, and bath condition affect stripping time. Use our result as a specific shop example, and allow for different results on a wheel, a heavily coated part, or another coating system.
5. Rinse and dry the parts
After removal, rinse thoroughly with fresh water according to the directions, then dry the parts before continuing with the next preparation stage. Rinsing and drying are straightforward in our workflow, but they are separate from the 10-minute soak.
Collect used solution and contaminated rinse water for appropriate disposal. Keep stripper out of drains and the environment, and check disposal arrangements with the manufacturer or a qualified waste service.
What we do before applying new powder coating
Removing the old finish is one part of getting our pieces ready. After stripping, rinsing, and drying, our shop process continues with:
- Ceramic tumbling
- Outgassing
- A final chemical wipe-down
- Powder coating
We use the ceramic tumbler as part of our surface preparation. Outgassing and the final wipe are additional preparation steps in our workflow. Choose the preparation and cleaning products appropriate to your metal and coating system; our sequence describes how we handle our own parts.
That is why I separate stripping time from total preparation time. A 10-minute soak gets the old coating off our example batch, while the remaining work prepares the pieces for their next finish.
How we watch the condition of the bath
Stripping speed is the first thing I watch. When similar parts start taking longer under the same conditions, it tells me the bath needs attention. Check temperature and the coating being removed as well as the condition of the solution before deciding how to service it.
We start our shop bath with undiluted product and have used water top-offs as the level drops. Replenishment needs more care than simply returning the liquid to the same level: evaporation and solution carried out on parts are different losses. Water does not replace the stripping chemical that leaves on a part, so repeated water-only additions can dilute the bath.
Use the manufacturer’s maintenance guidance to decide when to add water, fresh product, or replace the bath. The official FAQ notes that removing accumulated coating residue and replenishing with fresh product may extend its useful life.
Questions about timing and temperature
Will every part strip in 10 minutes?
No. That was our result for 50 Fastback handle pieces using our preferred bath conditions. Different coatings, parts, and solution conditions can take different amounts of time.
Can I use a lower temperature or soak parts overnight?
My experience is that cooler baths take longer. The published operating range is 150–175°F. Confirm any unheated or extended-soak process with the manufacturer for the specific alloy and coating; overnight soaking should not be treated as a general instruction for every part.
Do I still need to prepare the surface after stripping?
Yes, plan for the preparation required by the new coating. In our shop, the process includes ceramic tumbling, outgassing, and a final wipe after the old coating is removed.
Why we use this process at EZ Home
I started looking for another way to remove powder coating because sandblasting every piece took too long. Being able to strip 50 handle pieces in one bath changed how we handle our knife batches.
If coating removal is slowing down your work, compare a batch using your own parts, coating, and complete process. Include warm-up, handling, rinsing, drying, and surface preparation so you know what the change would mean in your shop.
See Nanner Peel Mad Scientist and read the current directions and Safety Data Sheet before setting up your stripping bath.