FAQ

Frequently Asked Questions

1)      What type of welder is best for truck frame repair?

a)       A MIG welder is probably the easiest to operate, as you will not have to worry about striking an arc in a tight area.

2)      How powerful does my welder need to be for frame repair?

a)       Your welder should have a max output of at least 140 amps.

3)      What Welding Rod should I use?

a)       We recommend E7018 Welding Rods.  Our personal favorite is the Lincoln Electric Carbon Steel E7018 H4R, 1/8” x 14”.

4)      What's the difference between MIG and stick welding for frame repair?

a)       For frame repair, MIG welding is often preferred due to its ease of use and the cleaner, stronger welds it produces on the thin steel commonly found in Truck frames. However, stick welding may be used for certain applications where thicker materials or difficult angles are involved. The choice often comes down to the specific repair needs and the welder's skill level.

5)      Do I need to use flux-core wire, or can I use solid wire with shielding gas?

a)       For truck frame repair, either method can work well, but many technicians prefer the solid wire with shielding gas approach. The cleaner welds and lack of flux residue can make the final repairs look more professional. However, the flux-cored wire may be more forgiving of less-than-ideal base metal conditions. The choice often comes down to the welder's preference, access to equipment, and the specific repair requirements. If you use the proper settings and techniques, both methods can produce strong, durable welds for truck frame repair.

6)      What welding wire thickness should I use for frame repair?

a)       For welding truck frames, the recommended wire thickness can vary depending on the thickness of the frame material, but here are some general guidelines:

i)        Light-Duty Truck Frames (1/8" to 3/16" thick):

(1)    Use 0.035" or 0.045" diameter mild steel solid wire or flux-cored wire.

ii)       Medium-Duty Truck Frames (3/16" to 1/4" thick):

(1)    Use 0.045" or 0.052" diameter mild steel solid wire or flux-cored wire.

iii)     Heavy-Duty Truck Frames (1/4" to 3/8" thick):

(1)    Use 0.052" or 1/16" (0.062") diameter mild steel solid wire or flux-cored wire.

7)      How do I set the correct voltage and wire feed speed on my welder?

a)       Correct voltage is crucial for creating good welds and typically, we would suggest you use the chart that came with your Welder, it is usually on the inside of the lid.  If you do not have the chart, here is a step-by-step guide.

i)        Determine the base material thickness:

(1)    Measure the thickness of the truck frame components you will be welding.

ii)       Select the appropriate welding wire diameter (see question 6)

iii)     Set the welding voltage:

(1)    Start with a voltage setting around 18-22V for MIG welding mild steel.

(2)    Increase the voltage as the base material gets thicker to improve penetration.

(3)    Use a higher voltage for larger diameter wires.

(4)    Adjust the voltage until you achieve a smooth, stable arc.

iv)     Set the Wire Feed Speed

(1)    Start with a wire feed speed around 300-400 inches per minute (IPM).

(2)    Increase the feed speed as the base material gets thicker to maintain the correct deposition rate.

(3)    Use a higher feed speed for larger diameter wires.

(4)    Adjust the feed speed until you achieve the desired weld bead width and penetration.

v)       Monitor the weld appearance:

(1)    Look for a smooth, even bead with minimal spatter.

(2)    Adjust the voltage and/or wire feed speed if the weld appears too narrow/wide, shallow/deep, or uneven.

b)      The optimal settings will depend on your specific welder, the base material thickness, and the welding wire diameter. It is best to start on the lower end of the settings and gradually increase them until you achieve the desired weld quality. Make sure to follow the welder manufacturer's recommendations as well.

8)      What safety gear do I need when welding a truck frame?

a)       Welding Helmet: Protects your eyes and skin from sparks, UV, and infrared rays 

b)      Hand Protection: Heavy-duty leather welding gloves to protect your hands from heat, sparks, and sharp edges

c)       Welding Jacket: Protects you from flash fire and electric arc flash

d)      Foot Protection: Sturdy, rubber-soled Steel-Toed shoes that are slip resistant, flame retardant, and cover past the ankle

e)      Fire-resistant skull cap or balaclava hood: Protects your head from burns and UV radiation

f)        Respirator: A NIOSH-approved respirator or welding fume extractor to filter out welding fumes

g)       Fire-Resistant Welding Blanket to cover surrounding flammable materials and prevent fires

h)      Hearing Protection: Earmuffs or Earplugs

i)        Proper ventilation to disperse welding fumes

9)      How do I prepare the frame surface before welding?

a)       Thoroughly clean the area by removing rust, paint, grease, and other contaminants using a wire brush, grinder, or sandpaper, then degrease the surface with a suitable solvent like acetone to ensure a clean metal-to-metal contact for optimal weld penetration.

10)   Should I remove paint and rust before welding? If so, how?

a)       Yes, contaminants like paint, rust, and dirt can weaken the weld's structural integrity and lead to cracking or failure.

b)      For rust and paint, use 80 to 110-grit sandpaper.

11)   How can I tell if the metal is too thin to weld?

a)       Typically, you want to stay from welding on metal below 3mm (about 0.12 in) in thickness. Below this thickness, the risk of burn through, distortion, and poor weld quality increases significantly.

i)        If you encounter thin frame sections that seem challenging to weld, use a lower heat input process like oxy-acetylene or braze welding or consider reinforcing the area thicker steel splice plate.

12)   What is the best welding position for frame repair?

a)       Flat Position

i)        Welding in the flat position (with the frame horizontal) is often the easiest and most stable.

ii)       It allows for good access, visibility, and control over the weld puddle.

iii)     Flat position welds tend to be the strongest and most consistent.

b)      Horizontal Position:

i)        If the frame member is oriented horizontally but not flat, welding in the horizontal position can work well.

ii)       It requires more skill than a flat position but allows for better access in tight spaces.

iii)     Maintaining the welding pool and avoiding undercutting can be more challenging.

c)       Vertical Position:

i)        Vertical welds may be necessary when repairing vertical frame members or components.

ii)       Welding upwards in the vertical position requires more technique and practice to avoid sagging or trapping slag.

iii)     Tack welding first can help provide a stable base for vertical welding.

d)      Overhead Position:

i)        Overhead welding is the most difficult position, as gravity works against the weld pool.

ii)       Overhead welding may be needed when repairing the underside or top of a frame.

iii)     Overhead welding requires excellent control and should be avoided if possible.

13)   How do I avoid warping the frame while welding?

a)       Focus on proper joint preparation, use a well-planned welding sequence, and employ techniques like intermittent welding and tack welding.  Careful control of the welding process, strategic fixturing, and gradual cooling are key to minimizing warping and distortion when repairing truck frames. Taking the time to do it right will result in a stronger, straighter frame.

14)   What is the proper technique for welding overhead on a frame?

a)       Use a 0.035” Diameter Wire

b)      Reduce Welding Current (start around 18-20V for MIG and adjust as needed)

c)       Maintain A Tight Welding Arc and avoid pulling the Arc away from the work surface

d)      Travel fast with short welds in 1–2-inch segments

e)      Use Stringer Beads instead if Wide Weaves

f)        Allow for proper cooling for each weld segment as quenching the welds can induce more distortion

15)   How do I know if I am getting good penetration with my welds?

a)       Visual Inspection:

i)        Look at the backside or root of the weld bead.

ii)       A good penetrating weld will have a flat, even appearance on the backside.

iii)     Excessive convexity or irregular bead shape indicates insufficient penetration.

b)      Bead Appearance:

i)        The weld bead on the surface should be smooth, even, and slightly convex.

ii)       An excessively wide, flat bead can signal lack of penetration.

iii)     A narrow, penetrating weld will have a more rounded, moderately convex profile.

c)       Weld Strength Testing:

i)        Destructively test some sample welds by cutting, bending, or breaking them.

ii)       Good penetration will result in the base metal failing before the weld.

iii)     If the weld itself fails, it is a sign of insufficient penetration.

d)      Dye Penetrant Inspection:

i)        Apply dye penetrant to the weld and look for any cracks or lack of fusion.

ii)       Lack of weld penetration will show up as linear indications on the surface.

e)      X-Ray or Ultrasonic Testing:

i)        These non-destructive techniques can provide detailed views of the internal weld structure.

ii)       They can reveal issues like incomplete root penetration or lack of fusion.

f)        As a general guideline, you want to see penetration of at least 80-100% of the base material thickness for a high-quality, structurally sound weld on your frame.

16)   What should a good weld look like on a truck frame?

a)       Smooth, Even Bead:

i)        The weld-bead should have a uniform, consistent appearance without any major irregularities or undercuts.

ii)       There should be no obvious craters, pits, or other discontinuities in the bead.

b)      Moderate Convexity:

i)        The weld bead should have a slightly convex, or "crowned" profile.

ii)       Excessive flatness or concavity can indicate insufficient penetration.

iii)     The bead height should be 1.5-2 times the thickness of the base metal.

c)       Uniform Width:

i)        The weld width should be relatively consistent along its length.

ii)       Dramatic variations in bead width can signal inconsistent travel speed or wire feed.

d)      Proper Tie-In:

i)        The weld should blend smoothly into the base metal at both toes (edges) of the bead.

ii)       There should be no undercut or sharp transitions between the weld and base material.

e)      Minimal Spatter:

i)        There should be very little splatter or beads of excess molten metal around the weld area.

ii)       Excessive spatter can indicate issues with the welding parameters or shielding gas.

f)        Shiny, Metallic Appearance:

i)        The cooled weld bead should have a shiny, metallic luster, not a dull or oxidized look.

ii)       This indicates proper shielding gas coverage and a clean, quality weld.

g)       No Visual Defects:

i)        Inspect the weld for any cracks, porosity, slag inclusions or other visible flaws.

ii)       These are signs that the welding procedure or technique needs improvement.

17)   How do I test the strength of my welds?

a)       Visual/Dimensional Inspection:

i)        Carefully inspect the weld for visual signs of quality, like those discussed previously:

ii)       Uniform bead profile and appearance

iii)     Proper penetration and tie-in to base metal

iv)     Absence of cracks, porosity, or other defects

v)       Measure the weld size (leg length, throat thickness) to ensure it meets specifications.

vi)     This type of non-destructive inspection can provide insight into weld integrity.

b)      Hardness Testing:

i)        Use a portable hardness tester to measure the hardness of the weld metal.

ii)       This can indicate if the weld has the proper metallurgical properties.

iii)     Hardness should be consistent with the base metal and within acceptable ranges.

c)       Dye Penetrant or Magnetic Particle Inspection:

i)        These non-destructive techniques can reveal any surface-breaking defects in the weld.

ii)       They may identify cracks, lack of fusion, or other issues not visible to the naked eye.

18)   Are there any specific techniques for welding in tight spaces on a frame?

a)       Use a Spool Gun:

i)        A spool gun allows you to feed the welding wire directly from a small spool, rather than a large roll.

ii)       This makes it easier to maneuver the welding gun into tight, confined areas of the frame.

iii)     The compact spool gun design provides better access and control.

b)      Consider MIG Welding:

i)        MIG welding is generally easier to control in tight spaces compared to stick welding.

ii)       The continuous wire feed and shielding gas provide a more stable, concentrated arc.

iii)     Stick welding can be challenging due to the need to manipulate the electrode.

c)       Employ Short-Circuit Transfer Mode:

i)        When MIG welding in tight areas, use the short-circuit transfer welding mode.

ii)       This produces a smaller, more controlled weld pool that is less prone to sagging or bridging.

iii)     Avoid the spray transfer mode, as the larger weld pool is harder to control in confined spaces.

d)      Utilize Flexible Welding Cables:

i)        Opt for flexible, lightweight welding cables and leads.

ii)       This makes it easier to maneuver the welding gun and power source around obstructions.

iii)     Avoid stiff, heavy-duty cables that can be cumbersome in tight quarters.

e)      Angle the Welding Gun:

i)        Position the welding gun at a 10–20-degree angle relative to the work surface.

ii)       This helps direct the arc and weld pool in the desired direction in tight spaces.

iii)     Avoid perpendicular gun angles, as they can lead to poor access and visibility.

f)        Weld in Smaller Segments:

i)        Instead of attempting long, continuous welds, break them up into shorter, overlapping segments.

ii)       This provides better control of the welding pool in restricted areas.

iii)     Quench each weld segment thoroughly before adding the next one.

g)       Use Compact Welding Machines:

i)        Portable, lightweight welding power sources are easier to maneuver in tight frame areas.

ii)       Avoid bulky, floor-mounted machines that are difficult to position.

19)   How do I deal with different metal thicknesses when welding frame parts?

a)       Using the correct amperage for the thinner material and heating up the thicker part can help in achieving a successful weld.

20)   What should I do if I burn through the metal while welding?

a)       Since burn-through is just a hole, filling it is the obvious solution. If it is a small hole, tack a small weld on that spot. If it has rough edges, you may want to grind them off before adding filler. Sometimes, you may experience multiple burn-throughs throughout the entire joint. To fix this, simply make another pass over the existing one.

21)   How do I properly ground my welder when working on a truck frame?

a)       Having the grounding clamp within a few feet and touching clean/bare metal will provide the best ground.

22)   Are there any parts of the frame I should avoid welding?

a)       Avoid welding anything containing fuel. Avoid welding anything that is supposed to move relative to another section. Avoid welding anything that is meant to be separated.

23)   How long should I let the welds cool before moving or stress-testing the frame?

a)       Until they are cool enough to touch. (DO NOT TOUCH AREAS YOU JUST WELDED)

24)   Do I need to do any post-weld treatments to strengthen the repair?

a)       Use primer and paint or other coatings to prevent corrosion.

25)   How can I prevent rust on my new welds?

a)       Use primer and paint or other coatings.

26)   When should I consider the frame damage too extensive for DIY repair?

a)       You should refrain from DIY repairs when there is nothing substantial to weld our products on to, and the time and money it would take to repair would bankrupt you.

27)   How do you get your Mig Welder in tight places like the top of the frame rails?

a)       Yoga, Gymnastics, and a dash of luck. Otherwise unbolt the body/bed/cab and carefully/slightly lift until top of the frame rails are accessible