I live in Texas which most people already know is really hot pretty much all year. It is mid December right now and it is 80° outside. So I am going to go over some of the filaments that I have used outside as well as how they hold up in the high temperatures.
PETG is the best filament for 3D printed parts that are going in a hot car or in direct sunlight. PETG has a melting point at 260°C (500°F) and begins getting soft around 160°C (338°F). A vehicle’s steering wheel that is parked in direct sunlight can reach as high as 95°C (200°) in the summer.
PETG will never be able to get hot enough to start melting, even if it is in a closed vehicle in direct sunlight and in the middle of a desert.
What Temperature Does PETG Start To Deform?
PETG starts to soften and deform at around 160°C. PETG has great thermal resistance and is used across many industries for its durability as well as thermal resistant properties. PETG is also great for use in a hot car for phone holders as well as sunglass holders.
It is very unlikely that PETG will deform in a hot car so this is a great go to when making parts for the cab of a car or even for small clips or pieces for the outside of a car.
Will PLA melt in a hot car?
PLA can get hot enough to deform and potentially melt in a hot car. PLA has a melting point between 170° and 180° celsius and will start to deform as low as 60° celsius. The cabin of a hot car can get as hot as 95° celsius meaning PLA is not an ideal filament for the hot cabin of a car.
What filament has the highest melting point?
Here is a list of the most common 3D printer filaments, and as you can see if you are wanting to print something that is extremely heat resistant, nylon is the way to go and if you are just needing something that is good for general heat resistance then PETG is an amazing choice.
Many of the filaments on this list might seem not as good as others because of their melting point but that is not the case at all. Each of these filaments has a purpose and is able to perform its own duty very well.
Nylon – 250°c
Nylon has an extremely high melting point and another key characteristic is that it is very friction resistant. If you are ever needing spacers for gears or simply two parts that have a lot of friction between each other check out nylon.
Carbon Fiber – 250°c
Carbon fiber is a bit of a tricky one because there are so many carbon fiber alloys created with virtually every other type of filament. Carbon Fiber PLA,
Polycarbonate PC – 240°c
Polycarbonate is hard as well as shatter resistant. Polycarbonate is basically the next step past the standard 3D printer as far as capabilities go. Polycarbonate has many applications outside of 3D printing such as glasses lenses.
ASA – 240°
ASA (Acrylonitrile-styrene-acrylate) is a great ABS like filament with a very high melting point making it great for use in a hot car. ASA is designed for high resistance to the outside elements as well as high heat resistance.
PETG – 230°c
I like to think of PETG as the Steel of 3D printing filaments whereas PLA is more the aluminum of 3D printing filaments. PETG is really great for everything, it is safe to 3D print, does not typically require any upgrades for your printer, and is extremely durable. PETG is also awesome because it is food safe as well as dishwasher safe.
HIPS – 230°c
HIPS is a great choice for supports as well as infill that you are wanting to later remove. This will require a dual extruder 3D printer. HIPS is a soluble filament that dissolves when placed in a Limonene solution.
ABS – 200°c
ABS is probably the most frustrating filament to work with. Not only does it release toxic fumes when printing it also requires special work conditions such as an enclosure. I am not a huge fan of ABS.
I am not a huge fan of ABS due to it releasing toxic fumes while printing. For that reason I suggest PETG over ABS.
Anything with a lower melting point than ABS is not a great choice when printing parts for the inside of a hot car cabin.
PVA – 190°c
PVA is another soluble filament with the unique characteristic that it is soluble in water. If you have a complex print with many supports as well as a dual extrusion 3D printer you have a recipe for success on your prints with PVA.
PLA – 170°c
PLA is the fan favorite and as i mentioned in the PETG section it is basically the Aluminum of filaments. Easy to work with, cheap, and soft. PLA is the go to for most of my prints due to its low cost as well as its ease of use.
PP (Polypropylene) – 160°c
Polypropylene is not very heat resistant but it is highly resistant to chemicals as well as electricity making it great for electrical components.
TPU – 150°c
TPU is a flexible filament that is not very heat resistant at all. If you use TPU for a print that is going into a hot car you are likely going to end up with a big mess at the end of the day. TPU is great for creating components such as stamps and
BASF Ultrafuse 316L – 250°c
I put both of these BASF Ultrafuse filaments at the bottom of the list becase of the comlexity that comes along with using these filaments. The average hobbiest will not venture into these filaments.
BASF Ultrafuse 316L is a metal 3D printer filament that is very similar the the 17-4 varient the main thing to acknowledge when using these BASG ultrafuse filaments is the they will require post processing and the process can not be done at home.
BASF Ultrafuse 17-4 – 250°c
BASF Ultrafuse 17-4 is a metal stainless steel filament that has to be run slow and hot. It is one of the best heat resistant filaments on the market and can be printed on a standard 3D printer such as a Prusa MK3 or an Ender 3.
Like the BASF 316L this filament requires post processing.