Mechanic Reacts to JB Weld Nightmares

Summary

This video features mechanics analyzing over-the-top DIY car repairs from TikTok using JB Weld epoxy, including trying to fix a transmission line, manifold leak, and brakes. They discuss proper applications and limitations of JB Weld, stressing the importance of preparation and it being a temporary fix rather than a permanent solution. The video also covers questionable Bondo repairs and using spray foam and fiberglass for rust holes. Overall, the mechanics critique the haphazard fixes but acknowledge some clever makeshift solutions, emphasizing repairs should be done properly to avoid future issues.

Takeaways

• 😀 JB Weld is very versatile but has limitations for permanent fixes on high pressure systems like transmission lines
• 👷‍♂️ Mechanics use JB Weld for temporary patches but say it requires proper surface prep and curing time
• 🚗 The video shows clips of questionable and creative JB Weld repairs from social media
• 🤦‍♂️ Using JB Weld on brake drums, exhaust manifolds, engine blocks is not recommended by mechanics
• 🛠 They advise replacing faulty parts instead of jury-rig patches which often fail anyway
• 🔨 Mechanics demonstrate proper use of JB Weld to repair a rust hole, with sanding and patches
• 😕 Too much Bondo body filler causes cracks and moisture damage over time
• 🏭 Foam injection to fill rust holes doesn't prevent future rust
• 👍 A mechanic carefully repairs a hole with JB Weld instead of welding
• 🤔 One person makes a whole cylinder out of JB Weld showing its versatility

Q & A

What are some examples of poor DIY car repairs featured in the video using JB Weld or other adhesives?

The video shows people using JB Weld to try to repair transmission lines, exhaust manifolds, engine vacuum leaks, and even entire brake drums. Other questionable fixes include using duct tape on engine vacuum leaks and attempting to glue a cracked differential cover back together with JB Weld.

Why is JB Weld not an ideal solution for fixing car parts like transmission lines or exhaust systems?

JB Weld does not handle high pressures or temperatures very well. Transmission lines operate at around 300 PSI pressure which JB Weld cannot withstand. Exhaust system temperatures can exceed 2000°F which will cause JB Weld to become brittle and fail.

What are some best practices for properly using JB Weld on a vehicle?

Proper use involves cleaning and sanding the area, applying thin layers of JB Weld, allowing proper curing time, and only using it for small repairs on low-stress areas. It works well for small holes, cracks, or surface imperfections but not for critical components.

How can Bondo be misused when repairing body panels?

Applying Bondo too thickly in one area can lead to cracking when the body flexes while driving. It is meant for thin applications to smooth small dents and imperfections, not for covering large damaged areas.

What was the demonstration of making a cylinder out of JB Weld showing?

The cylinder demonstration showed that with enough time and effort, JB Weld can be molded into complex shapes like an engine cylinder. However, it is not practical for actual engine repairs due to not withstanding heat and pressure.

What should be done to properly repair rust holes instead of just covering with Bondo or foam?

The rust should be completely cut out, then new clean metal welded into place. Covering over rust with cosmetic applications will eventually fail as the rust continues to spread under the surface.

What risks are posed by using duct tape on engine vacuum leaks instead of properly repairing them?

The adhesive can get pulled into the engine and cause catastrophic failure. Even if it holds temporarily, the oil and heat will degrade the tape until it fails, potentially while driving.

Why can JB Weld or Bondo repairs cause problems for mechanics working on the vehicle in the future?

The homemade fixes with adhesives can make it much harder to properly access fasteners, engine components, or body panels for future repairs. Mechanics often have to waste time removing the amateur work first.

What are some temporary quick fixes shown that are actually reasonable in a pinch?

Using JB Weld farther back on exhaust leaks, attaching a socket with JB Weld to remove a broken bolt, and securing a loose heat shield are actually decent temporary solutions until a full repair can be done.

What are the risks of continuing to drive a vehicle with makeshift repairs instead of proper fixes?

The repairs are likely to fail unexpectedly while driving, leading to breakdowns or dangerous failures like brake malfunctions. Proper repairs should be done as soon as possible for safety.