Anyone know if the black plastic tub just above the spare tire is a thermoplastic, and if so about how high the melting temperature is? I have purchased a spare black plastic tub and will attempt to reform it to accommodate a full-sized spare where the high pressure donut is normally located. Knowing the working temperature of,the plastic would help but I will otherwise do trial and error, but as I paid $75 for the tub I would rather not needlessly ruin it. Thanks in advance for any info!
The spare tire tubs are made of expanded polystyrene plastic, which means that it is a heat formable thermo plastic. It will start to soften at the 150-160 degrees Fahrenheit range and slump at the 300 degree range.
The wide black plastic pan above the spare tire of my 2011 is labeled >PP-TD10< , meaning polypropylene that's 10% talc-filled. Polypropylene is a very common thermoplastic. The white pad under the spare tire is expanded polystyrene (the stuff commonly called "styrofoam.")
Still, the working temperatures are the same. Paper and natural leather is more resistant to heat deformation than plastics. The only high temperature working plastic is PEEK, which is very expensive.
Found "PPTD10" on the underside of the pan after I inverted it for cleaning. Side question: why 10% talc fill? Does talc alter any significant property or is it just a cheap filler? To fit the full sized spare the white styrofoam pad under the donut will be discarded shortly. Does melting polypropylene out gas anything noxious? Weather has improved here so I can do it outside, but controlling the reforming process might be easier if done indoors. Unfortunately I do not own a respirator, so the noxious gas issue is pertinent.
Talc increases the bulk and rigidity of the polypropylene. Polypropylene won't outgas noxious fumes unless it is burnt. Under 400 degrees, there should be almost NO fumes.
