The Best Way to Paint Galvanized Metal

Painting galvanized metal requires some preparation to ensure proper adhesion and durability. Galvanized metal has a zinc coating to protect it from corrosion, but this coating can make it challenging for paint to adhere. Here's the best process:

1. Clean the Surface

• Remove dirt and grease: Use a degreaser or soapy water to remove any oils, dirt, or grease from the surface. Rinse thoroughly and allow it to dry.

• Eliminate white rust: If there is white rust (a chalky residue from the zinc), scrub it off with a wire brush or fine-grit sandpaper.

2. Scuff the Surface

• Use fine sandpaper (120–150 grit) or a scuff pad to lightly roughen the surface. This helps the primer and paint adhere better.

• Wipe down the surface with a clean, damp cloth to remove sanding dust.

3. Choose the Right Primer

• Use a primer specifically designed for galvanized metal, such as a zinc-rich or self-etching primer. These primers adhere well to zinc-coated surfaces and create a good base for paint.

• Apply the primer in thin, even coats according to the manufacturer’s instructions. Allow it to dry completely.

4. Select the Proper Paint

• Opt for an acrylic latex paint or a paint specifically formulated for galvanized metal. Avoid alkyd- or oil-based paints unless they are explicitly labeled for galvanized surfaces, as these can react poorly with the zinc coating.

5. Paint Application

• Apply the paint using a brush, roller, or spray, depending on the size and shape of the surface.

• Use thin, even coats and let each coat dry completely before applying the next one. Typically, two coats are sufficient for full coverage.

6. Cure and Protect

• Allow the paint to cure fully before subjecting the surface to heavy use or outdoor elements.

• For additional protection, you can apply a clear sealant or topcoat if needed.

Tips:

• New galvanized metal: If the metal is newly galvanized, it may have a shiny surface that makes adhesion difficult. Let it weather for a few weeks or use a vinegar solution (1:1 vinegar and water) to etch the surface before priming.

• Test adhesion: Before painting a large area, test the primer and paint on a small, inconspicuous spot to ensure they adhere well.

Following these steps will ensure your painted galvanized metal is durable and looks great for years.

Sheet Metal Cutting Tools: Straight and Bulldog Tin Snips

Why are my cuts coming out so jagged!? Why don't these snips cut a radius well? Why do all of my long cuts A.) Take so long and B.) Have all these little notches every inch or so?

You may or may not have asked yourself these questions or many others while hacking through a piece of tin. 

I've had all these frustrations over the course of my career and some of those issues come down to experience cutting with any kind of tin snip by hand. However, another answer could be that you may be using the wrong snips for the job. One size does not fit all when it comes to sheet metal cutting tools. 

The one tool that I would have gold plated and mounted on the wall of my office is a pair of Straight Tin Snips. They are on the front of our company T-Shirts and will forever be a building block of any micro tin shop.

Straight Tin Snips I use daily

Known as Lather Snips to some, I have always labeled them as straight cut tin snips or shears. I have spent over 15 years of my working life cutting straight duct, plenums and fittings by hand with these and other kinds of tin snips. However, these were by far the Labron James of snips in my Tin Knockers tool bag and on the sheet metal fabrication table.

The manufacturer will tell you wide curves can also be cut, and to a point, you can with the Straight Cut. However, I would argue that the longer handle Bulldog Pattern Snips provide an easier cut when dealing with radius shearing. The Bulldogs are for "nibbling" heavier gauge and they do a great job in that forum. But they do a much better job than the straight cut snips when you have to cut a 40" flat elbow cheek and especially when cutting smaller radius lines by hand. Bulldogs saved me a lot of frustration on those days when fittings prioirized the schedule. 

Bulldog Tin Snips We Use Each Day

The straight cut snips hang up too much as you make your way through the radius. They can't make the corner nice, especially on those tighter curves. Think of a good handling car versus a bad one. Both vehicles can make the turn. However, you can feel the difference if you've driven the car that really handles well in the corner. It can make all the difference when time is of the essence. 

Having both pairs of snips at your disposal can only help your fabrication prowess. 

Every sheet metal worker, roofer or HVAC technician will have a pair of Straight Tin Shears at the ready. They are tried and true; the backbone of a Tin Knockers tool bag. I would bet many of them carry a pair of Bulldogs as well.

Today at K & E Sheet Metal they have taken a back seat to the CNC plasma table and pneumatic jump shear, but they still hold tremendous value in our shop on a daily basis.  They were the tools that built this company to where we could afford the plasma table and jump shear.

If you're working in the field and you don't have a pair in your tool bag, do yourself a favor. And if your're starting a small fabrication shop, they are a must. Those aviator snips you may have picked up at the local Home Depot are immensely important when it comes to sheet metal cutting tools, but they will soak up your time and forearm strength in seconds.

The Straight Cut Tin Snips and Bulldog Pattern Snips will help take care of that problem and keep your cuts straight and true.  

Happy Cutting!

SaraSpa Rod & Gun Club Duct Fabrication

After installing the filter boxes and elbows shown in my previous post, it is now time to fabricate the next set of duct and transitions that will run up the wall. There are three total units and each will need a 90" drop. Below are the in-progress fittings lined up in a pretty little row.

Our next task is to cut and install the Ductmate Flange System on each section of duct for easy installation when we get to the jobsite.

Wolla!

We finished up a few 90 elbows with turning vanes for the job as well. Probably could have managed a better photo but I had to assist my helper uncle with that tub of screws :)...JK

SaraSpa Rod & Gun Club Duct Installation Photos

Here are a couple pics from our most recent duct installation at the SaraSpa Rod and Gun Club in Greenfield Center, NY.

Installation of the Exit Air Unit ductwork and filter cabinet.

Installation of Make-up Air Unit duct.

The job has been progressing nicely with a lot of custom duct and fittings. Each section is fabricated with 24 gauge metal and secured together with the Ductmate Flanging System.

There is a light at the end of the tunnel regarding finishing up the installtion and fabrication. I hope to get all the photos gathered together and share them after the project is completed. With our move to a new fabrication shop space and other jobs, time has been at a premium. We are finally getting back to a somewhat normal schedule.