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Ultra-Blak Rectifier - Liquid Additive for Black Oxide Chemicals

Ultra-Blak Rectifier - Liquid Additive for Black Oxide Chemicals

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How to Use Ultra-Blak Rectifier

Adding Ultra-Blak Rectifier to a black-oxide bath forces iron sludge or buildup to float to the top, making it easy to skim from the surface and remove the contaminants.

Use Ultra-Blak Rectifier to:

Control the buildup of iron sludge and contaminants in black-oxide baths
Decontaminate black-oxide baths in 10–15 minutes
Avoid undesirable copper deposits and iron films
Achieve purer, more beautiful black finishes

Ultra-Blak Rectifier is used to control the buildup of sludge, red iron oxide, zinc, aluminum, and copper in Ultra-Blak 400 or other black-oxide solutions.

Samples available to purchase - CALL #262-786-9330.

PLEASE NOTE: Orders ship within 3 business days.

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How to Use Ultra-Blak Rectifier

Adding Ultra-Blak Rectifier to a black-oxide bath forces iron sludge or buildup to float to the top, making it easy to skim from the surface and remove the contaminants.

Use Ultra-Blak Rectifier to:

Control the buildup of iron sludge and contaminants in black-oxide baths
Decontaminate black-oxide baths in 10–15 minutes
Avoid undesirable copper deposits and iron films
Achieve purer, more beautiful black finishes

Product Questions (15)

Customer Questions

Can EPi process parts for me?

Yes! EPi's staff would be more than happy to process sample parts for you. We actually prefer it that way, so that you can see exactly how the finishing looks on your parts, and you can be sure you'll be happy with the results. Please fill out the Parts Submission Form here.

Are there distributors of EPi products near my location?

Please call EPi at 262-786-9330 or email: us-sales@epi.com.

Where can I find a technical data sheet (TDS) or safety data sheet (SDS) for EPi's products?

These documents can be found on each product page. You can download PDFs of TDSs, SDSs, product brochures, and more.

When will my order ship?

Please see each individual product page for more information on the availability of each item. We try to process and ship non-sample orders in 3 business days. Samples and Trial Kits have a 5 business day lead time to process and ship. Also, after placing your order, you may click the "Account" link at the top right-hand side of our site to track the status of your order. You will receive a shipment confirmation when your order has shipped and tracking information within 24–48 hours of shipment.

How do I track my order?

Click the "Account" link at the top right-hand side of our site to track your order.

How do I return a product?

Please call us at 262-786-9330 or email: us-sales@epi.com.

Does EPi ship to international countries?

EPi's ecommerce site cannot accept online online orders from outside the continental United States. To place an order for shipment to Alaska, Hawaii, Puerto Rico, or an international country, please call 262-786-9330 or email us-sales@epi.com.

How do I create an account?

Click the "Login or Register" link at the top right-hand side of site.

What is black oxide?

Black oxide is a blend of caustic, oxidizers, and additives that is used on ferrous metals. There are three types of metal blackening: hot, mid, and room temperature blackening. EPi was the first company to offer all three processes. Hot black oxide (285 F°) is a conventional hot process which produces a true black oxide iron magnetite (Fe3O4) finish. It is a premium-grade salt mixture which will blacken a wider range of steel alloys than any other process on the market. Mid-temperature black oxide (225–245 F°) is the latest development in blackening processes, producing a true black oxide iron magnetite (Fe3O4) finish. It produces no caustic boiling fumes and provides a safer working environment. Room-temperature blackening (65–85° F) is the preferred metal-blackening process for safe and convenient in-house blackening. It is an excellent non-bleed black finish for powdered metal and cast iron. It produces super deep blackness and corrosion resistance equal to hot oxide blackeners. It is important to note this is not a true black oxide process; however, it may be referred to as room-temperature black oxide. Room-temperature blackening processes are autocatalytic reactions of a black selenium-copper compound that deposits on ferrous parts through an immersion process.

What makes EPI’s black oxide and metal-blackening processes better?

Insta-Blak processes do not produce smutty rub-offs like other room-temperature products. Our Ultra-Blak products are premium-grade black oxide, and Kool-Blak does not produce a smutty rub off like other mid-temperature processes. They are easy-to-use with wide windows of operation.

What are the advantages of black oxide and metal blackening?

Ultra-Blak:

Produces true black oxide finish Fe3O4 magnetite finish
Abrasion resistance
Corrosion protection
Meets military spec MIL-DTL-13924D and AMS 2485H
Blackens faster than other hot black oxides
Less sludge generation than other hot black oxides, which means lower gas bills

Insta-Blak:

Capital costs less than $10,000–15,000 for turnkey operations
Energy savings
No CO2 emissions or green house gases
1–5 minute process time for blackening
Powder metal does not bleed-out white salts like hot black oxide
Cast iron and steel castings do not turn red
No ventilation costs
Provides corrosion resistance
Dimensional stability thickness 5–10 millionths of an inch
Can be painted over
Anti-galling properties
Aesthetic appeal

What can black oxide be used for?

Black oxide can be used on a wide variety of metals. Examples of specific products that can be blackened with black oxide are listed below.

Locks
Automobile and motorcycle parts
Machine parts
Power tools
Hardware and electornic hardware
Architectural applications
Furniture
Ironware
Exercise equipment
Large metal sheets
Gears
Hydraulic and pneumatic components
Lawn and garden equipment
Candle holders
Fasteners
Storefronts or displays

Who uses black oxide?

Large companies such as lock manufacturers or auto manufacturers use black oxide on a large-scale basis to blacken metal parts. Black oxide can also be used by the home hobbyist who would prefer to blacken just a few items. Below are some of the major industries that use black oxide coating.

Ammunition manufacturers
Appliance industry
Architectural industry
Auto industry
Camping and hunting
Collars/coupling industry
Construction equipment industry
Fastener industry
Firearms
Hardware industry
Metal stampers
Military components
Oilfield Industry
Power hand tool manufacturers
Recreational vehicle industry
Tool & die industry
Tube cutters/fabricators

How is black oxide applied?

Hot- and mid-temperature black oxide is applied through a seven-step process.

Clean and degrease metal parts
Rinse metal parts
Hydrochloric acid
Rinse metal parts
Blacken parts in boiling solution (hot: approximately 285 F°, mid: no boiling, 225–245 F°)
Rinse metal parts
Seal and finish

Room-temperature metal blackening is applied through a five-step process.

Clean and degrease metal parts
Rinse metal parts
Blacken metal parts 1–5 minutes at 65–85 F°
Rinse metal parts
Seal and finish

Some steels require an additional prep and rinse, adding two more steps.

How to prevent blackened parts from getting rusty?

Customers reach out to us asking how to prevent their freshly blackened parts from rusting. EPi recommends: Use running water to rinse the parts for 1-2 minutes; Do not dry the parts between prepping, cleaning, and blackening; Do not use compressed air to dry the parts as it contains water droplets; Apply E-Tec (see instructions) sealer to extend the life of the finish and protect the surface. One of our customers shared their experience/process with us. After analyzing their process, we concluded that using compressed air for drying the parts may lead to rusting. Below is their process:

Using a cleaning solution on the parts
Rinse in Distilled water
Soak in Black Oxide Concentrate, currently mixing 8 to 1 with Distilled Water
Rinse in Distilled Water
Soak in oil

We weren’t originally drying the part between each stage, except when we went from cleaning solution to initial rinse. We are now drying each part with compressed air between each stage, but finding similar issues. Freshly blackened parts The same part overnight The same parts after a week.

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