Repairing a Crack in a Dirt Bike Fender Using the ATV Pro Welder

This dirt bike fender has a very long crack. Luckily, this type of damage can be easily repaired with Polyvance’s DIY-friendly ATV Pro airless plastic welder. Polyvance’s ATV Pro welder comes with either polypropylene welding rod or polyethylene welding rod in the round 01 profile. This fender is made of polypropylene, so selected the polypropylene rod to match.

Always wear proper safety gear while working!

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Click here: https://www.youtube.com/watch?v=tHctO3LBcrk

Products Used:

Note: This is a list of the Polyvance products that can be used to make this repair. This list does not include sanders, grinders, or other common tools you will need. If you have any questions, please don't hesitate to call technical support at 800-633-3047.

• 1000 Super Prep Plastic Cleaner (several options available) OR 1001-4 EcoPrep Plastic Cleaner
• ATV PRO airless plastic welder
• Stainless steel reinforcing mesh (included with the welder)
• Red polypropylene welding rod (30 feet of polypropylene or polyethylene welding rod is included in the welder in the color you choose)
• Aluminum Body Tape (several options available)

Video Notes:

• English Closed Captions have been provided for this video. Click on the CC button to turn them on or off.
• The length of this video is in no way representative of the actual time required to perform a complete repair and therefore should not be used for estimating purposes.

Music Credits:

• "Sage" by Slenderbeats
  From the YouTube Audio Library

Narration:

• Rob Rode

English Transcript:

This dirt bike fender has a very long crack. Luckily, this type of damage can be easily repaired with Polyvance’s ATV Pro airless plastic welder. In this video, we will describe our repair process on this fender.

First, we cleaned the damaged area with plastic cleaner to remove any contaminants from the surface. Because of the severity of the damage, we needed to fixture the crack together at the edge before we applied aluminum tape. We cut a small strip of stainless-steel wire mesh and embedded it into the plastic at the edge to keep the crack aligned. This allowed us to apply aluminum tape securely to the cosmetic side. Aluminum tape is used to support the crack and prevent melted welding rod from pushing through.

Next, we began our airless plastic weld. Polyvance’s ATV Pro welder comes with either polypropylene welding rod or polyethylene welding rod in the round 01 profile. This fender is made of polypropylene, so we selected the polypropylene rod to match. Because this is a fusion weld and not an adhesive weld, it’s important that both the base material and the welding rod are melted and mixing together.

First, we used the tip of the welder to melt an indentation in the plastic about an inch or two long. This does two things: it makes a trench in the plastic that serves as a v-groove, and it melts the base material so the welding rod will fuse to it properly. Next, we fed the welding rod through the tube in the tip and laid the tip on the surface of the plastic. We slowly pushed the rod through the tube and into the indentation we made. Once we had enough plastic melted, we used the welder tip to mix the rod and the base material together and smooth the weld. The key to this type of repair is to only work in small sections. You don’t want to weld too big of an area at one time, because the plastic will cool down before you have time to thoroughly mix and smooth the plastics. We continued to weld down the crack with this method. When we got to a section with a large chunk of plastic missing, we added extra welding rod to cover the missing area.

After the welding on the backside was complete, we determined that some areas of the fender needed extra reinforcement. We placed some stainless-steel mesh down onto the plastic and laid the welder tip over it, melting the rod beneath the mesh. When the plastic was melted, we pushed the mesh into the plastic with a metal tool. We smoothed the melted plastic over the top of the mesh to cover it up and neaten the appearance.

Once the plastic was cool, we removed the aluminum tape from the cosmetic side and applied it to the backside. We welded the cosmetic side of the fender the same way we welded the backside. We melted a groove in the plastic, fed the welding rod through the welder tip, and pushed the melted rod into the groove. Once we had enough plastic melted into the groove, we mixed the welding rod and base material together and smoothed the weld. We worked in one-to-two-inch sections at a time until we finished welding the entire crack.

After allowing the welds to cool to room temperature, we started our cosmetic work. We began sanding with 80 grit sandpaper, moved to 180 grit, then 320 grit, and finished with 600 grit. Finally, we lightly went over the sanded areas with a blowtorch to return the color and shine to the plastic.