5 Frequently Asked Questions When Welding a Vehicle Frame

Last Updated on July 2021

Like many welders and vehicle owners, you might be having a set of questions that have been disturbing you when it comes to welding a vehicle’s frame. Here are 5 most asked questions and our expert response to each one of these questions.

1. Is It Unlawful to Weld a Vehicle Frame?

Let’s separate this question into two subcategories:

  1. The lawfulness of working a vehicle on the roadway with a welded frame
  2. The lawfulness of selling a vehicle with a welded frame

You ought to seek an expert’s legal guide when you need genuine lawful advice regarding this matter.

Proper preparation procedures, equipment, and best practices should be guiding pillars any time you want to any on any vehicle frame.

Working with a commercial vehicle such as a large truck, bus, transport, 18-wheeler, and so forth, with a welded frame on a highway isn’t permitted as per the Federal Motor Carrier Safety Administration Title 49: Subtitle B: Chapter III: Subchapter B: Part 393.201 (d). However, in rare circumstances, such as the manufacturer’s recommendations, there are exemptions to this prohibition

This isn’t astounding considering the exacting guidelines that are forced on commercial vehicles – typically because of safety concerns.

This equivalent article from the FMCSA prohibits the penetration of openings in the top or base rail flanges, except when specified by the manufacturer. This is a consistent idea among commercial and light-duty consumer vehicles.

When any vehicle’s frame rails have been re-welded, cut, drilled, or in any case, changed or repaired, there is a likelihood that that vehicle may not be permitted to drive on the highway anymore.

Without a doubt, if these vehicles with changed frames are not allowed to operate on the highway anymore, the vehicle can be enlisted as “off-highway only” and limitations become considerably looser.

However, with the help and input of a qualified fabricator, the vehicle’s structural integrity is enhanced.

In short, if you are in question about whether your vehicle is lawful to work on the highways because the vehicle has a welded frame, get professional legal advice.

The last thing you need to happen is to get into a crash and your vehicle insurance drops your policy in the wake of discovering inadequately done welding repairs on the vehicle’s frame.

Ensure an expert tackles your job!

A professional welder workingIt is normally not unlawful to sell a vehicle with a frame that has been welded on (kindly counsel your local laws – this article should not be considered as lawful advice), yet it is unlawful to sell a vehicle that has a welded frame or with frame risk without telling the purchaser first.

The way that selling a vehicle with a welded frame can be considered unlawful becomes evident when the vehicle’s safety and worth are in doubt.

For instance, if an individual has a pickup truck and chooses to weld a tubular pre-runner bumper on the facade of the truck, afterward offers the truck to a purchaser, he should reveal that the frame has been welded since there is a danger that the safety of the vehicle has been compromised (non-Original Equipment Manufacturer vehicle parts were added).

Also, there is always the question regarding the worth of the vehicle after a frame has been welded – regardless of whether the welded frame is seen to add esteem, for example, with the pre-runner bumper.

If you are selling a vehicle with a frame that has been welded, it is always a smart thought to compose a report of the vehicle’s condition. In the report note the state of the vehicle’s frame, and potentially adding some photographs to that report.

If you have the purchaser sign a statement recognizing the vehicle’s condition, you have a basis to be covered if the buyer gets into a mishap or decides to document an automobile fraud against you.

This report, regardless of whether it may not genuinely be legitimate in design, shows the dealer’s total honesty and the purchaser’s affirmation, which should go far in case of any legal issues thereafter.

Laws in regards to the offer of a vehicle can shift contingent upon the state that you are in at the time of sale. However, it will always help to get professional legal to lawful advice when selling a vehicle with a not-so-good condition.

The above is more so if the vehicle’s worth is high, for example, with huge trucks or even 18-wheeler farm tractors.

2. What Sort of Unique Equipment Do I Have to Weld on a Vehicle Frame?

You don’t have to worry much about the equipment as long as you have your normal welding outfit including welding PPE, welder, gas, and processor, and so on, you shouldn’t require any extraordinary gear to accomplish a fundamental weld on a vehicle frame – yet there are exemptions.

In cases where you are welding a channel inside or structural tubing onto the vehicle frame, some unique pieces of equipment may be useful tooling to add to the devices available to you, such as a plasma shaper.

You can find such special equipment particularly valuable for welding on a vehicle frame when the body of the vehicle is as yet joined. This ensures there can be extremely restricted mobility between the frame rail and the vehicle body.
In the case of car autobody restoration welding shops where vehicles are restored from the beginning, a typical piece of equipment is a vehicle rotisserie.

Vehicle rotisseries are used to pivot a whole vehicle.

Having the option to pivot and rotate the vehicle makes it simpler for the specialist dealing with the vehicle. Activities under the vehicle don’t need to be performed overhead while the automobile is on a conventional vertical vehicle lift.
These “vehicle rotisseries” or vehicle rotators are usually sold by instrument retailers such as Northern Device or Redline Designing.

Expert tip- If you are unsure what is the correct amperage to use with a given piece of material, whether aluminum or steel, thick or thin, it is always a good idea to first try a weld bead on a waste piece of material similar to the actual metal work-piece you intend to weld. This practice will save you time and effort as well as ensure you don’t damage the only material you want to weld.

3. Will Welding Frame Pieces Together Cause a Crack?

If the vehicle’s frame should be welded together either for off-highway use or whenever performed per the vehicle producer’s recommendations, some broad suggestions should be followed to help forestall cracks in the frame.

The golden rule for the welding on a vehicle frame is to keep away from a single vertical butt joint where the two parts of a frame are joined from top to bottom with a single weld.

Irrespective of the shape and size of the vehicle frame, it will undergo extraordinary load during its lifetimes. So, having this kind of butt weld is the sure way to have your frame cracking.

More reasonable strategies for welding frames make the joint a lot more grounded to avoid additional cracks and breakage.

The usual way of thinking about welding frame joints is to ensure the joints (sides, top, and base) are close to 45 degrees. This is meant to ensure there is the maximum weld bead and surface area to spread the pressure load on the weld joint.  Extra reinforcement methods incorporate fish plating over the highest point of the welded region or potentially adding underlying tubes or channels either inside or over the highest point of the frame rails.

You can’t over-reinforce/over-engineer your repair area. However, you can debilitate the metal encompassing the repair area because of welding heat. This can make different areas crack. So, be cautious about your heat-affected areas.

These frame reinforcement strategies are common among smaller and bigger vehicles. Bigger vehicles require thicker reinforcing plates and channels (if the vehicle maker suggests it).

One issue with bigger trucks is that their frame rails are at times heat-treated to a precise specification to optimize their solidness and strength.

Welding on these frame rails comes with a high-risk factor since the heat-treated frame rail material close to the repair plate/channel material may cause cracks. These cracks arise because of the dissimilarity between the two metals.

Huge trucks which have heat-treated frame rails, like semi-truck tractors, are firmly managed by the DOT in the US and you may not pass forthcoming DOT inspection with the welding-related repairs you perform on your frame.

4. Will Welding on the Vehicle Frame Damage the Vehicle’s Comp?

There are different views with regards to whether or not welding on your vehicle frame (or something else) will damage your vehicle’s installed computer system.

Answers to this inquiry vary from “You’ll be fine as long as you use your grounding cable “to “there is a critical danger of damaging your computer – you truly shouldn’t attempt.”

The supporting data for both of these answers are persuading, however, there is a typical answer that thinks about electrical engineering science: “indeed, you can weld on the frame of your vehicle, yet you need to make certain precautions.”
These follow electrical engineering science. However, as we have all learned with ongoing vehicle reviews, auto specialists in some cases settle on odd plan choices which might change this perceived commonsense approach.

Hence, before you begin welding on your vehicle frame, or elsewhere on your vehicle, check what your vehicle’s and the manufacturer have to say. But as a general guide, ensure you do the following-

  • Always place the welding ground clamp as close as conceivable to your welding arc to limit the electrical path between the arc and the ground. By doing this you lessen the danger of high voltage getting to your vehicle’s delicate computer parts.
  • Always separate the negative battery terminal from the vehicle so you open the electrical circuits in your vehicle to your battery. Doing so decreases the danger of overvoltage which may destroy your vehicle’s computer.
  • Every time detach the airbag plugs in the engine of your vehicle. There is a slight possibility that some welding voltage might get to your airbags and trigger them to go off. This is the last thing you need since airbags are pricey.
    Following these prudent tips takes out practically all the danger related to welding on your vehicle (in regards to damaging your onboard computer parts. However, if you need to eliminate this risk, your most ideal alternative is to detach your vehicle’s ECU.

But then, separating your vehicle’s ECU has its ramifications, for example, possibly upsetting the OBD2 system and vehicle power/air-fuel maps.

ECU’s are expensive to replace. So, it is always shrewd to be cautious with your onboard Computer system when you want to weld your vehicle frame.

5. Would It Be a Good Idea for Me to MIG or TIG Weld My Vehicle Frame?

There are endless factors that determine the quality of the finished weld.  Thus there is no assurance that by choosing MIG or TIG welding you’ll get the best welding results on your vehicle’s frame.

Some factors are inalienable with each of the MIG and TIG welding processes that have a solid connection to the nature of a weld.

The more critical factors include:

  • Welding process
  • Welder expertise
  • Filler material determination/communication with the base material

Welding experts develop their skills in certain welding processes and probably might be as capable in other forms and aspects of welding.

For instance, an expert TIG welder who welds on aluminum boat railings professionally doesn’t have the very scholarly strategies that a car body fix specialist may have. Because of this basic reality, one welding specialist can make a top-notch weld with a MIG machine and another welding expert can make a low-quality weld with a MIG machine.

For discussion’s sake, we will assume welding expertise doesn’t matter- hold it as a constant- as we take a look at the other factors.

There are more options of filler material for TIG welding processes which is a benefit when compared to MIG welding where the welder needs to run the wire through the feed tube.

Most stamped steel edges can be welded with either MIG or TIG welding processes. But when a vehicle has intricate curvatures or chrome-moly tubing supports, for example, with motorcycles or with racing frames, TIG welding is your ideal choice.

TIG welding provides a far superior weld when welding together auto frames that contain high alloy steels. These metals are heat sensitive and may be prone to cracks in the zone affected by heat.

Also, MIG welders, if not set up properly, can lead to “cold starts” making the penetration of the base material incomplete. This, in turn, creates a weld where the joint is compromised in certain areas.

In short, it depends. If your application includes anything more strenuous or extreme such a racing, off-road, or otherwise, then TIG welding is most likely your best choice for welding on a vehicle frame.

Expert Tip: All MIG welders are unique, and all welding applications are extraordinary. When you track down your ideal weld setting for your MIG welder (for your particular application, record this on paper and append it to the side of your welder. This will save you from the agony that comes when another operator uses this machine, or the machine gets knocks, and your settings are lost.

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