IMCA Modified Chassis - Welding Basics

So, for all of you IMCA Dirt Track hopefuls, here is an article about the core of racing -- i.e. the Chassis. This months feature will discuss the basics of IMCA Chassis Frame welding, and how it is the foundation of your dreams to get out on that compacted clay surface we Dirt Boys call a track.

MIG welding also refereed to as wire-feed welding, makes use of a continuous and consumable wire filament which is fed through a trigger activated welding gun. This trigger also blows Argon gas onto the weld to protect it from the oxidizing atmosphere which can contaminate the weld. This method was developed for welding nonferrous metals, but it was found to be very advantageous for welding DOM steel tubing as well as all other cold-rolled steel products.

This is most common welding method used to fabricate IMCA Modified Chassis. If you focus on a few basic rules, and take time to practice, wire feed welding can help make the fabrication or repair of your IMCA Modified Chassis much safer and much simpler.

Keep it Safe (stupid!)

Not to be a-hole, but I have seen -- first hand -- too many unnecessary burns because my workmates were using more balls than brains while welding in the shop. This is because a lot of people slack on safety as welding becomes more comfortable, but, never forget, wire-feed welding can be very hazardous -- especially when you “ain’t payin’ attention!”

The shock from a 120 V mini-welding machine could easily kill the operator, so you ought to always know whether your machine is plugged in, and whether it’s “live” or not. And, you ought not ever weld in a rush.

The number one safety tool you will need is a welding helmet with an auto darkening visor. This will protect your eyes against unexpected sparks. You will also need a long sleeved fire retardant welding jacket and welding gloves. Last, but not least, you will need tight and grounded machine connection with a dry and clean workspace.

And, whatever you do, never -- ever -- weld in shorts. Especially if your legs are as harry as a silverbacks on prom night... (dumbass!)

Clean your Plate (slob!)

I cannot stress enough how important it is to keep a clean work-area before and during welding. The best surface to weld on is a thick honed steel table. I also like to weld on a stone surface, but steel tables allow you to connect the ground clamp directly to the table. The electric current will pass through table to the piece you are welding, and create the arc.

If you do not have adequate flow from your argon tank the weld will start to scab-over with black soot. This is called carbon, and it is the last thing you want mixed in with freshly molten metal welds holding together you IMCA Modified Chassis. This can cause micro-pockets in your welds which will significantly increase the chances that the weld will crack. Given the stress IMCA Racing puts on a Modified Chassis it is very important to keep your welds clean.

Another critical safety tip is to avoid welding zinc coated steel -- also known as galvanized steel. The arch from the weld will burn the zinc coating creating a mildly poisonous gas called zinc-oxide. I had the misfortune to learn this the hard way while sweating copper pipes using zinc flux paste. I developed flu-like symptoms, the most prominent being aching joints. It felt like I had aged 20 years in 2 days, and I could not, for the life of me, get out of bed. I found out I had inhalation sickness, or what welders and plumbers call “metal fume fever.” It was one of the worst sicknesses I have ever had to overcome.

To hedge against metal fume fever ol’-school welders drink a lot of milk before and during welding. There seems to be something in milk, maybe the calcium, that helps fight the effects of welding fumes, but I have found the best way is to 1) use a high powered fan blowing away from your face, 2) use rosin flux when sweating copper, and 3) don’t weld galvanized steel. Also, welding galvanized steel is pointless unless you get the piece re-galvanized, because it burns off the zinc at the seam which will rust. Save yourself money, and protect your health by using new steel, and getting it galvanized or powder-coated after you finished.

Stick it out just enough to get her really hot. (no, not that!)

“Sickout” is a term welders use to set the distance between the tip of the gun and the arc. If you are too far the weld will not arc -- if you are too close the tip of the gun could get fused to the steel you are welding. Keeping a distance of 1/2” is usually good, but each stickout varies depending on the welder and the thickness of the material. Also, your machine settings, and your wire-speed will play a big part in your stickout. (we’re still talking about welding, right?)

Read the gol' darn INSTRUCTIONS!!!!

We men are genetically predisposed to never read the instructions. Also, our “man-pride” will stop us from asking for help when have no clue what we are doing. Read the manual that came with your welding machine, and practice on scrap metal (a lot!) If you are building your first race car, and you spent all you money on a welder you don’t know how to use, the last thing to do is keep at it and use all of your nice DOM steel tubing. You will burn through more time, wire, steel tubing, and money than you could ever imagine. Get help from a friend who knows what they are doing, take a night-class at your local tech-school, or just do what you are good at -- your day job -- and save your money to buy a professionally made IMCA Modified Chassis. There are a number of great, reasonably priced, IMCA Modified Chassis builders who can get you into the race. Addiction Chassis, in Helper--Utah is the young-gun of the IMCA Modified Chassis world, but one of the best. Check out their website at www.addictionchassis.com or find a quality IMCA Modified Chassis builder in your area.

Save your balls for the track, and use your brains in the shop. Remember -- 90% of winning is done in the shop, and in the pits. Preparation cannot be substituted. This is a great sport, but she’s a very dangerous mistress, and she will mess-you-up if you do not respect her -- especially you noobs (i.e. new guy.) Use your best tool first -- your brain -- accept what you are good at and accept that which you cannot change. Money is the least you could lose with a poorly welded IMCA Modified Chassis.

Especially coming out of turn 4 -- on the last lap.