No one considers what kind of material a tractor hood is composed of, even that of a John Deere tractor until it cracks and it has to be repaired. John Deere tractors are almost entirely manufactured in John Deere manufacturing facilities so some materials have been kept proprietary, including the material in John Deere Hoods.
What we do know is that John Deere lawnmower, tractor, and gator hoods are made out of polycarbonate plastic. What all goes into that polycarbonate is not as clear since John Deere is pretty close-mouthed about it. That doesn’t change the fact that they can be effectively repaired, however.
The fact is, John Deere hoods get cracks in them. It’s an unfortunate eventuality with anything plastic that drops down over an engine, so it’s not just a John Deer thing. The problem is, that DIY repairs are a little difficult when no one knows what the hoods are made out of.
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What is Polycarbonate?
When polycarbonate molding is complete, it becomes a hard and rigid shell, which is what makes it so popular in so many applications. Polycarbonate is everywhere and you will find it in lawnmowers, automobiles, Blu-Ray discs, lighting (both industrial and residential), and even in eyeglasses.
In recent years, polycarbonate has found its way into 3D printing and even in smartphones as a more impact-resistant material. It makes sense that polycarbonate would be used in the manufacturing of lawnmowers or tractor hoods, as they can take quite a beating.
Unfortunately, polycarbonate is susceptible to heat, as heat is used to mold it in the first place. Rapid or large changes in temperature can cause cracking in the material or sufficiently weaken it enough to crack after even a small impact.
When it comes to lawnmowers and tractors, there are a ton of environmental and internal stressors that can affect the hood of a John Deere. For one, when operating, the vibrations alone can be pretty intense, along with the heat rising from the engine beneath.
The opposite is true during the winter and the argument can easily be made that frigid temperature makes polycarbonate so rigid that it shatters when impacted. Since it is already molded into a shape, rather than shatter, it will crack, sometimes through from one end to the other.
Repairing Cracked Polycarbonate John Deere Hoods
There is a meticulous way to go about repairing a cracked John Deere hood but you need to make sure that you have all of the tools necessary before you get started.
- Plastic welding rods
- Rotary tool
- A sharpie or permanent marker of some type
- Rubbing alcohol
- Plastic weld epoxy
- A brush with stiff bristles
- Sandpaper, fine grain
- John Deere green paint and primer for plastics
- Duct tape
You’ll also need to separate the hood from the John Deere to repair it properly, however, if you can’t separate it, you need to keep it open and angled to a point where you can work on it.
Start from the outside of the hood. All of this is the most basic and simple restructuring of the plastic with your hands. You want to bend the plastic back into its original shape, holding the cracked pieces together so that they almost seem to bond again, on their own.
A second person would be handy to run tape along the opposite side of the crack as you hold it together. You just need the tape to hold the split polycarbonate together long enough to do the rest of the work.
Now, move to the inside of the hood where your cloth and rubbing alcohol will come in handy. Some people recommend acetone for this part, however, acetone has a nasty habit of eating away plastic if applied too, liberally, so it’s best to stick with rubbing alcohol to clean the areas around the cracks thoroughly.
Marking and Applying Weld Plastic
Mark your crack from one end to the other on the inside of the hood, then insert a plastic welding rod into the rotary tool. As the rotary tool spins the plastic welding rod and one end is touched to the beginning of the crack, the friction will cause the plastic welding rod to melt.
As you spin the plastic welding rod, move along the crack at a 45° angle, allowing the plastic enough time to melt into and fill the crack. When it’s all said and done, allow it a few moments to cool before you sand it all down with your sandpaper.
That’s all there is to it. Of course, you can purchase fiberglass cloth and use an epoxy resin to adhere it to the surface if you want to go through those extra steps, however, the bond created with the plastic welding rods will be far stronger than you realize.
Benefits of Polycarbonate
We know that extreme cold and extreme levels of heat can deform or shatter polycarbonate but that only happens when extremes are involved. You’re not going to get a cracked, polycarbonate John Deere hood just because the outside temperature dropped to 50° one day.
Since we know the weaknesses of polycarbonate, what are its strengths and benefits?
- Polycarbonate is highly durable
- It has excellent weatherability
- It’s flexible enough to mold if need be
- It’s not a toxic plastic
- It’s good for recycling
- It has a good deal of heat resistance
It’s easy to see why John Deere decided to go with polycarbonate as it is an exceptional plastic with plenty of longevity and durability, especially considering what lawnmowers and tractors have to go through.
It doesn’t fade over time, like a lot of other plastics and you can see why that would be an attractive point for John Deere because the famous green color is half of the selling point and a polycarbonate plastic that holds its color is a positive all around.
Its flexibility stands out as well. Because it is flexible, polycarbonate is easy to fix, such as the above-mentioned method where the pliability of the plastic is crucial to holding the cracks together so they can be taped.
Polycarbonate is also one of the few plastics that is considered to be environmentally friendly as it has a low level of toxicity in association with the environment and it is recyclable plastic.
Instead of simply trashing the originals when manufacturing new polycarbonate applications, the old can simply be recycled and used in the new. Polycarbonate can also get quite hot before it begins to increase in terms of flexibility.
This is a must-have attribute since polycarbonate hoods on John Deere tractors are exposed to the enormous heat of the engine, along with being out in the sun, which heats both sides extensively.
John Deere hoods are made of polycarbonate because of all of the benefits that polycarbonate plastics bring to the table. In the case that it does crack, it is easily repairable, so long as you have the tools necessary for the task.
While it’s not known exactly how John Deere manufactures its polycarbonate and what other processes, if any, go into the manufacturing, it is nevertheless a strong and long-lasting material for John Deere hoods in all of their lawnmowers, tractor, and UTVs.