Fabrication Basics: Jay Thornton’s tips

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Guest article on Motivicty’s MOTOBLOG, first in a series from Jay Thornton, custom fabrication expert and technical lead at Vibrant Performance.

I spend a lot of time working with up-and-coming custom metal fabricators and it’s one of the coolest parts of my job at Vibrant. I get to see a lot of new, creative ways of doing things and meet new people who bring a whole new perspective to the craft. I also see this as an important part in the art of fabrication: helping the next generation learn a craft that is constantly changing and innovating.

Because we work closely with Motovicity, we’ve recently begun work on what I’ll call Fabrication 101, Lessons in the Art of Custom Metal Fabrication. We’ll be creating a series of how-to’s and fundamentals, as well as demonstrating the differences between good fabrication and junk jobs.

We’ll also look beyond our four walls to see what’s happening out there in the field. We’ll get ideas from leading custom fabricators as well as meeting some people from the companies who make the tools of the trade.

But before we do any of that – before we begin any fabrication 101 – there’s really a “Fab .5” pre-fab level of understanding you really should know before anything else. These are the basics that I didn’t know starting out and which cost me a lot of lost time having to go back and re-learn the right way.

So if you’re just starting out, or have been fabricating for some years and want to improve your skills, this is making sure everyone’s on the start/finish line with the same base set of knowledge about fabrication and welding before we move on.

Breaking it Down

Art vs. Equipment vs. Metallurgy, with a dose of Terminology and Safety

One key thing people need to know is that fabrication and welding is as much an art form as it is technical. Often what looks good to the eye isn’t always the best in terms of performance and robustness. What makes one metal weld good can destroy another, and what makes one weld solid while the next one fails is sometimes only separated by a matter of degrees.

So to break it down, the pre-fab basics are understanding the art form, knowing what you need to know about equipment and metallurgy, learning the terminology, and always thinking about your safety. That last one might sound like a buzz kill, but let’s look at it like this: you’re working with stuff that can permanently injure you without you even knowing it. There’s a lot of ways this stuff can sneak up on you and screw with you, and once you’re hit, you can’t go back to do it over. You’re done. You’re career could be over, or worse.

So you’re gonna want to stick around for that.

The Art of Fabrication

They say that beauty is in the eye of the beholder. That’s never been more true than in the art of custom fabrication. Why does one fab job make the front page of Fabrication Life and the next one get passed around as a joke on Facebook? Well for one, there’s never an excuse for sloppiness. I see it all the time, the wrong parts cut in the most insane ways and with welds that looked like they held the pipe with their feet. Sometimes the gene pool is kind of shallow for some and there’s just not a lot you can do to help them.

After pure incompetence, I see shoddy work coming from a combination of laziness and poor planning. They’re kind of the same, but when it comes to planning, I look at it like this: For every minute I spend planning a project, I save 10 minutes in the shop. A lot of times I’ll shoot some digital pictures of my project, do some measuring and sketch things up on my computer or on a sheet of paper.

Planning is king.

This is where skill and artistry meets. It’s where I try out the different options, look up the product guides, and even look at what others have done in similar situations online. (Fabrication Life is one good place for ideas.) For myself personally, I see this sort of philosophically. That’s to say, I want to leave my mark upon this earth before I’m done. I’ll do that by creating performance art with my hands. I will strive to make the next weld better than the last. I will eat, sleep, absorb all that I can to create the type of work that people see and wonder: Who created that?

Yes, it’s pride. It’s also devotion and the need to be about something bigger than yourself. It’s about owning everything there is to the craft and then absorbing everything surrounding it – the smell of the leather texture to my hands, the feel of the cold metal, watching the burn of the filler rod as I twist it to make every nuanced wave of molten metal as perfect as I can. How the gases cool the surface as the bright orange glow fades to become the soul of my next creation.

Fabrication is about art and purpose. If you’re not into the lifestyle, you’ve probably already turned the page or clicked on the next link. But if you are, then you know this is where you need to be and you need to know where you’re going with your craft. If you don’t care about yourself or your profession, it will show. If you do and you own it, people will beat a path to your door asking for more. It’s as simple as that.

Find your place, get there, own it.

Before we go any further and talk about tools and materials, we should get this out of the way.


If you don’t know what you’re talking about, you’ll never have any credibility as a fabricator. It’s not that we talk our own language, we just have our language of the trade. It’s not all that different from other skilled trades, but still unique to fab shops.

So to get you over the hump, here’s a short list of fabrication terms alphabetized for your convenience.

Butt Weld – A weld joint where the two materials butt up together, rather than overlapping, and are joined by a weld. (See also fillet weld, lap weld)

Cold Weld – Also colored and bumpy, ridged – too cold, not absorbing filler fast enough into the weld area.

Color/Discolored – Describes the color of the weld due to oxidation. Most of the time people equate color as “cool looking” but in many cases it can be a sign of poor inert gas coverage and could mean a bad weld.

Torch and components – A TIG torch contains many smaller parts that make adapting to different weld types easy. For instance:

Collet – Pinches the tungsten when tightened between the collet body and the torch cap.

Collet Body – Holds collet and tungsten while having small nozzles to let inert gas pass through to the nozzle.

Collet Body with Gas Lens – Same as above but with a filter or screen to allow the inert gas to travel more evenly over the weld area. Usually used with larger nozzles.

Tungsten – The rod traveling through the TIG torch to carry the arc to the metal being welded. Also comes in different sizes and compositions geared to specific types of welding and materials.

Dimes, Droppin’ Dimes – Describes a good TIG weld pattern of concentric filler rod flows that resembles dimes laid out in a row.

Dirty Weld – A weld joint with small black spots in it, typically due to lack of proper material preparation and cleaning.

Fillet Weld – When two perpendicular pieces of metal are joined together by welding.

HAZ – Heat Affected Zone – The area of the weld heated from the arc outside the weld path.

Hot Weld – Very large HAZ on either side of weld that stretches into the materials welded and leaving it discolored. This is typically caused by too much amperage or too slow of a pass with the weld torch without adequate gas coverage. A hot weld can also be grey in color or brown, where the weld didn’t have the correct gas flow and torch options selected.

Lap Weld – A weld created when two layers of material overlap and are then joined by welding.

Nozzle – Generally made from Ceramic, Pirex or Alumina. It screws on the collet body directing the gas on to the weld area. They come in different diameters and lengths

Post Flow – Keeping gas flowing after the arc feed has stopped to keep the oxygen out of the weld area while the while joint cools.

Torch Angle – The angle of offset from perpendicular to the horizontal surface. This allows the welder to add filler rod while being able to see the weld and achieve the dime effect. Optimal is between 5-10 degrees from perpendicular to the weld puddle. Improper angles can lead to discolored welds and poor weld patterns.

Undercut – Where the weld path is left sitting lower than the two pieces being joined together.

Weld Puddle – The molten state of the material that you’re welding.

End of Part 1. Stay tuned for more tomorrow.

Jay Thornton is a veteran custom fabricator and technical lead at Vibrant Performance.