Rust Floor Pan: Repair Or Replace?

Repairing a rusted floor pan can be a costly and time-consuming endeavour, with the price depending on the extent of the damage and the method used to fix it. If the hole is not too big, a patch repair can be done, but for larger repairs, a partial or full panel replacement may be necessary. The cost of labour for repairing a floor pan can range from $300 to $2000, with the addition of the cost of materials, which can vary depending on whether a new or donor pan is used. Taking the time to do it yourself can save money, but it requires the necessary tools, space, and expertise.

Cost of floor pan repair

The cost of repairing a floor pan will depend on the extent of the damage, the repair method, and whether you choose to hire a professional or do it yourself.

Repair Methods

If the hole in your floor pan is not too big, you can opt for a patch repair. For larger holes, you may need to replace the damaged section with a partial panel. If the rust damage is extensive, it might be best to replace the entire floor pan with a one-piece panel.

DIY vs Professional Repair

If you have the skills, tools, and space, you can save on labour costs by repairing your floor pan yourself. However, if you don't feel confident or lack the necessary equipment, it's best to leave it to a professional.

Cost Breakdown

The cost of repairing a floor pan can vary. For example, a full floor pan can cost around $300 to $400, while patches for the front can be around $70 per side. Labour costs can add up, with sheet metal labour typically ranging from $35 to $45 per hour.

Case Studies

• A user on a car forum reported that they were quoted around $750 to repair typical floor pan rust in the corners of their car.
• Another user on a car forum shared that they were quoted $1,700 for labour and work on the driver's side rocker, plus the cost of a new floor pan ($465) and car rental ($250), totalling $2,415.
• The same user later found a second shop that quoted them $1,300 for labour to replace both pans and do the undercoating, plus the cost of the pans ($930) and car rental ($500), totalling $2,750.
• A user on Reddit estimated that a floor pan would cost around $100 to $150, and a shop would charge around $500 to replace it. They also mentioned that a full front and rear pan replacement would likely cost well over $1,000 after labour.
• Another Reddit user recalled getting a new floor pan installed at a custom car shop for $600, but this was five years ago.

Additional Costs

In addition to the cost of the floor pan and labour, there may be other costs to consider, such as car rental during the repair period and the purchase or rental of tools if you choose to do it yourself.

Preventing Future Rust

To prevent future rust, it's important to properly seal the floor pans after repairing them. Products like POR-15 can be used to seal and protect your floor pans from the elements.

Removing interior to save money

Removing the interior of your car can save you money when fixing a rusted floor pan. This is because it will take less time for the mechanic to do the work, and you will therefore pay less in labour costs.

If you are confident in your abilities, you could also save money by removing the interior yourself. However, this is only recommended if you have the necessary tools and space to do so.

Removing the interior of your car will also give you a better idea of the extent of the rust damage. This is important, as the severity of the rust will impact the cost of the repair. For example, if the rust is limited to surface rust or pinholes, you may be able to fix it yourself with a wire wheel and sealer. On the other hand, if the rust is more severe, you may need to weld in patches of fresh sheet metal or even replace the entire floor pan.

It is worth noting that attempting to repair rust damage yourself can be risky, as it is easy to make mistakes that could further damage your vehicle. Therefore, it is generally recommended that you consult a professional mechanic, especially if the rust damage is extensive.

In terms of cost, the price of repairing a rusted floor pan can vary depending on the severity of the rust and the labour rate of the shop. For example, one person reported being quoted $1700 for labour and materials to replace the driver's side floor pan and patch a hole in the wheel well. In contrast, another person reported being quoted $1300 for labour and materials to replace both floor pans and patch a hole in the rear wheel well.

To save money, it is recommended that you shop around and get quotes from multiple mechanics before deciding where to take your car for repairs. Additionally, you can supply your own replacement floor pan, which can be purchased new for around $300 to $465, or used for a lower price. Keep in mind that used floor pans may not be in perfect condition and could require additional work to fit properly.

Overall, removing the interior of your car can save you money when fixing a rusted floor pan by reducing labour costs. However, it is important to weigh this against the cost and effort of removing the interior yourself, as well as the potential for additional repairs once the full extent of the rust damage is revealed.

Using a MIG welder

Step 1: Remove the Carpeting and Floor Covering

First, remove the carpeting or floor covering to gain access to the rusted portions of the floor pan. This will allow you to assess the extent of the damage and determine the best course of action for repair.

Step 2: Assess the Damage

Once the floor pan is exposed, evaluate the damage. Determine whether the rust is limited to small areas or if it has spread to a larger section of the floor pan. This will help you decide on the appropriate repair method.

Step 3: Prepare the Area

If the rust is limited to small areas, you can use a patch repair. Clean the area around the rust and make sure it is free of any debris or dirt. You may need to use a grinder or wire wheel to remove any rust or damaged metal.

Step 4: Cut Out the Damaged Area

Use a cutting tool, such as an air-powered cut-off wheel, to cut out the damaged section of the floor pan. Make sure to only cut away the rusted metal and keep as much of the original metal intact as possible. Mask off the area to be repaired with masking tape and cut along the taped line.

Step 5: Prepare the New Panel

After cutting out the damaged section, clean the edges of the remaining floor pan using a grinder or wire wheel. This will ensure a solid, rust-free surface to weld onto. Prepare the new panel by trimming and fitting it to the cut-out area. Test fit the panel several times and make any necessary adjustments.

Step 6: Weld the New Panel

Clamp the new panel into place and tack weld it in position. Put down the welder and step back to check the alignment before final welding. Use a butt weld or lap weld to secure the new panel in place. A butt weld will result in a stronger joint with no overlaps, but it is more challenging to execute. A lap weld is easier to perform but will leave overlaps.

Step 7: Finish the Repair

After welding, apply a coat of primer and paint to the repaired area. This will help protect the new metal and prevent future rust. Reinstall the carpeting or floor covering.

Cost Considerations

The cost of repairing a rusted floor pan can vary depending on the extent of the damage and the method of repair. If you are taking your car to a shop, expect to pay for labour in addition to the cost of materials. The labour cost can range from $35 to $80 per hour, and the repair may take several hours to complete.

If you are repairing the floor pan yourself, the cost will depend on the tools and materials you need to purchase. A MIG welder can range in price, but you can find affordable options suitable for automotive bodywork. The floor pan itself will also contribute to the cost, with prices varying depending on the make and model of your car.

Butt vs spot welding

When it comes to fixing a rusted floor pan, there are several options available, including butt welding, spot welding, and lap welding. Here's a detailed comparison between butt welding and spot welding:

Butt Welding vs. Spot Welding

Butt welding involves joining two pieces of metal without any overlap, resulting in a clean and seamless joint. This method is often preferred by restorers aiming for a more authentic and original look. It is also stronger than spot welding and leaves no overlaps, reducing the risk of moisture buildup and future rust issues. However, butt welding requires precise fitting and can be more challenging to execute, especially for inexperienced welders.

Spot welding, on the other hand, is the technique originally used by car manufacturers. It involves creating a series of small welds along the joint, similar to the original construction of the vehicle. Spot welding is generally easier and faster than butt welding, as it doesn't require the same level of precision in fitting the panels. It is also a good option for those who want to maintain the structural integrity of the vehicle without spending a lot of time on the restoration process.

Considerations

When deciding between butt welding and spot welding, there are several factors to consider:

• Skill Level: Butt welding is technically more challenging and may not be suitable for beginners. Spot welding is generally easier and more forgiving.
• Authenticity: If you're aiming for an authentic restoration, butt welding will provide a more original appearance.
• Strength: Butt welding results in a stronger joint compared to spot welding.
• Moisture Control: Butt welding eliminates overlaps, reducing the risk of moisture buildup. Spot welding can be effective if properly sealed, but there is a higher chance of moisture seeping in between the panels.
• Time and Effort: Spot welding is usually faster and less labour-intensive than butt welding, which requires precise fitting and trimming of panels.

Both butt welding and spot welding have their advantages and disadvantages. Butt welding provides a cleaner, stronger, and more authentic finish, but it is more challenging and time-consuming. Spot welding is easier, faster, and more suitable for those prioritizing functionality over aesthetics. Ultimately, the decision between butt welding and spot welding depends on your skill level, the desired outcome, and the time and resources you're willing to invest in the project.

Patching vs full replacement

When it comes to repairing a rusty floor pan, there are two main options: patching the affected area or replacing the entire floor pan. Both methods have their advantages and drawbacks, and the best approach will depend on the specific situation and the resources available.

Patching a floor pan can be a good option if the damage is limited to a small area. It is generally less costly and labour-intensive than a full replacement, as it requires less material and can often be done without removing the entire floor pan. Patching can also be a good solution if only a specific section of the floor pan is affected, such as the driver's side, while the rest of the floor is still in good condition. In this case, a partial panel can be trimmed to cover only the damaged area, saving the original metal of the car.

On the other hand, replacing the entire floor pan may be necessary if the rust damage is extensive. While it will cost more and require more labour, it can be a better long-term solution, especially if the floor pan is structurally compromised. A full replacement will also add value to the vehicle and improve its appearance, both from the inside and underneath. Additionally, a full floor pan requires less finish work than a patch and can save time compared to cutting, welding, and fitting multiple patch panels.

The availability of parts and the skill level of the person performing the repair will also play a role in the decision. In some cases, partial pans or half pans may not be available for certain makes and models, limiting the options to either a full replacement or patching. Additionally, the quality of the installation is crucial. A poorly installed one-piece floor pan can negate the benefits of a full replacement, while a well-executed patch repair can provide a durable solution.

Ultimately, the decision to patch or fully replace a rusty floor pan should be based on a thorough assessment of the damage, the availability of parts, and the skill and budget of the person performing the repair. Both methods can be effective, but it is important to weigh the pros and cons of each approach to determine the best course of action for a particular situation.

Frequently asked questions