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Bonderized Steel: A Comprehensive Guide
Paul Rubio

By: Paul Rubio on February 28th, 2020

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Bonderized Steel: A Comprehensive Guide

Education | Homeowner Education | Bonderized Steel

So, you want a roof or a wall panel that looks old and has a dull matte gray finish. You are looking for a product that is inexpensive and not as shiny as galvanized or galvalume. The pictures of Bonderized corrugated or standing seam roofing look beautiful. Unfortunately, it is not that simple. Bonderized was NOT intended to be used as an unpainted and exposed roofing or siding panel.


Nowadays, Bonderized or Paint Grip is a fairly common type of metal roofing, but there are specifics about the product that you will need to understand. The first question that needs to be answered is “ Are you painting the Bonderized ?” Whether Bonderized is the correct fit for your project starts with that question as the material will perform differently when painted versus left exposed.

It will be in your best interest to contact a company that specializes in this type of material. You do not want to work with a company in which this is just another product. You need an expert that understands the intricacies of Bonderized, Rezibond®, Paint Grip, or painted products that look old and weathered gray. Our experts will answer all of your questions and then get you the best price on your Bonderized sheeting, coils, drip edge, gutters, downspouts, roofing, and wall panels.

This guide will cover:

  • What is Bonderized Steel?
  • Exposed Bonderized vs Painted Bonderized
  • Bonderized vs alternative products
  • How much does Bonderized cost?

What Is Bonderized Steel?


Bonderized is often referred to as " Paint Grip ". Bonderized steel is galvanized G90 that has gone through a phosphate bath. The phosphate acts as an insulator between the drying action of the galvanized coating and the paint, promoting longer paint adhesion. Then a layer of Chromate is applied and dried which makes it ready to accept paint. It is an excellent “ primer “ for painting applications. The bonderizing process produces a dull matte gray finish.

Paint Grip or Bonderized was designed to be painted. It holds paint well and is popular in the rainwater products industry. Typical uses are, rain gutters, downspouts, roof flashings, and roof valleys. Bonderized is NOT intended to be left exposed to the weather without being painted first. Bonderized should be painted immediately after installation as the phosphate coating can develop white rust if left exposed. However, it is commonly used in an exposed application for roofing, metal siding, and wall panels.


Bonderized Steel Finishes

Bonderized will perform differently when painted versus left exposed to the weather. Paint grip was created for the rainwater goods industry because it is easier to paint than galvanized. However, architects have fallen in love with this product because it is inexpensive and it has an old weathered gray look. They want it installed without a paint finish. Each of these conditions must be looked at differently.

Painted Bonderized Steel

When you purchase Bonderized the application matters. If you are painting the Bonderized then there is not much that can go wrong. The color consistency of the finish is irrelevant. It doesn’t matter who you purchase the Paint Grip from and I would recommend that you buy the cheapest Bonderized steel that you can find. It is completely different than buying Bonderized that will be used in an exposed application. All you need to know is how to paint the Bonderized.

Non-Painted Bonderized

Paint Grip is often installed in an exposed application such as Bonderized roofing or wall panels. When you have this type of field condition than you need to work with an expert. You need a company that specializes in selling Bonderized for exposed applications.

These are the most common issues when Bonderized is left UNPAINTED.

  1. No Warranty
  2. Inconsistent Finish
  3. Scratches Easily
  4. White Rust
  5. Wet Stacking

If you enjoyed this article we suggest that you read: Five Problems With Bonderized Steel And How To Solve Them


Bonderized vs Alternate Roofing Panels

Bonderized vs Paint Grip

Bonderized and Paint Grip are actually the same thing. Paint Grip is just a generic name that was given to Bonderized. The term originates from the fact that Bonderized was developed as a better solution than galvanized to have paint adhere to. If you have a galvanized job that needs to be painted Bonderized would be a better solution as it has a galvanized substrate and the paint will stick to it better.

Bonderized vs Rezibond Steel

Bonderized and Rezibond are very similar. They are both products that have a galvanized substrate and are designed as a better solution for paint to adhere to than galvanized.

Here are the differences:

    • Bonderized is dull gray and there is NO consistency to the finish. Some batches of Bonderized are a beautiful dark gray and others have a light gray finish with a yellow or green tint.
    • Rezibond is dark gray with black lines that run throughout the finish. The main advantage is the finish is much more consistent than Bonderized.

Bonderized vs Galvanized

Bonderized provides an ideal surface for field painting of wall panels, metal roofing, trim and flashings, gutters, downspouts, and signs. Both materials are bare steel that has a galvanized finish. Bonderized is just an extra coating that is applied on top of a galvanized finish. Here are the main differences:

    • Bonderized is ready to paint
    • Galvanized requires a primer coat
    • Bonderized cost more

You do NOT need to apply a primer coat to Bonderized. Simply clean the surface and apply a finish paint.

You have to clean, dry, etch, and apply a primer coat prior to painting galvanized.

Bonderized steel will cost about 20 percent more than galvanized steel. That number is misleading though as it does not account for all of the cost savings that are eliminated by not having to apply a primer coat to the steel.


Bonderized vs Painted Products

There is an alternate choice that will offer the same look and has a paint warranty. Painted panels that have a weathered gray finish. You are able to recreate the look of a 100 year old panel with new steel. This is a better product in every way except it will be forty percent more expensive than Bonderized.

Pre-Painted Metal That Looks Weathered Gray

How Much Does Bonderized Steel Cost?

Bonderized will cost 20 percent more than galvanized in coil or flat sheets. It is hard to list exact prices for this type of steel, but I will attempt to give a price range that will help with budgeting decisions

  • Bonderized Coil and Flats Cost
  • Bonderized Roofing Cost
  • Bonderized Wall Panels and Metal Siding Cost

The pricing for Bonderized coil and flats will vary depending upon the gauge of the steel, size of the job, and location of the job. Bonderized flats or coil will cost $ .75 - $.90 per pound or square foot.

Nearly all Bonderized roofing jobs are made from 24 gauge steel. The pricing for Paint Grip roofing will vary depending upon the panel profile, size of the job and location of the job. Bonderized roofing will cost $ 1.50 - $ 2.50 per square foot.

Bonderized wall panels are normally 24 gauge steel. The pricing for Paint Grip wall panels or siding will vary depending upon the panel profile, size of the job and location of the job. Bonderized wall panels will cost $ 1.50 - $ 2.50 per square foot.


Only Deal With Companies That Are Experts In Bonderized

If the Bonderized will be painted then buy the cheapest and most readily available steel. In this instance the type of Bonderized that you will end up with does not matter. Paint either adheres to it or it does not.

If you have a Bonderized roofing or siding job that is UNPAINTED and will be left exposed to the weather it is CRITICAL that you buy the Bonderized from someone that specializes in this application. You may pay slightly more, but you will end up with a much nicer product that has a more consistent finish. If your Bonderized will be unpainted always ask the vendor the following questions:

  1. Do you offer Bonderized samples?
  2. Is all of the Bonderized from matching batches?
  3. Do you apply strippable plastic to prevent scratches?

If the steel supplier does NOT do all of these things then you should find a different vendor. When evaluating suppliers, ask them about the problems they've encountered with Paint Grip and what they do to prevent them. The answers you get will speak volumes about who you should trust with your job.


Request A Free Bonderized Sample

When looking for metal roofing or siding in a matte gray finish, you have a few different options.

You can choose:

  • Bonderized steel that will be painted
  • Bonderized steel that will be left exposed to the weather
  • Painted panels that have a weathered gray finish that replicates Bonderized

Since there are pros and cons to each, you should consider all the factors this article has gone over for the different options to decide which material is best for you. At Western States Metal Roofing, we’re happy to help advise you on the best direction based on your project’s specific needs.

If you’d prefer to see the materials in person before you decide, we can send you a free sample of Bonderized or our weathered gray panels.

If you enjoy this article then we recommend that you read these also:

Five Common Problems With Bonderized Steel And How To Avoid Them

Four Common Problems With Rezibond And How To Solve Them


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About Paul Rubio

Paul Rubio is the Vice President and one of the owners of Western States Metal Roofing. He has been in the metal roofing industry for 25 years. WSMR is a manufacturer of metal roofing, wall panels, and metal siding. We have colors and finishes that nobody else has with nearly 100 different colors in stock. Our selection of color options and finishes is likely the largest in the industry.