How to Make DIY Automotive Body Filler?
2 Answers
Steps for preparing automotive body filler: 1. Purchase a can of polyester putty (also called body filler) as the base material from online stores or auto parts shops, then place an appropriate amount on a mixing board. 2. Add the hardener to the base material at a ratio of 100:2 to 100:3. Alternatively, high-concentration hide glue can be used as the hardener for polyester putty, as long as it can achieve curing. 3. Mix thoroughly until achieving a thick paste consistency before application. Two crucial precautions when preparing automotive body filler: 1. Strictly control the hardener quantity according to the mixing ratio. Otherwise, even with continuous stirring, achieving the desired paste consistency becomes difficult, which will significantly reduce the filler's adhesion and adversely affect subsequent painting processes. 2. The working time of polyester putty is limited (typically 10 minutes), so the mixing speed must be accelerated accordingly.
Back in my younger days as an experienced driver, I often used a homemade method for making body filler: mixing some gypsum powder with white latex adhesive, adjusting the ratio by feel until it reached a thick yogurt-like consistency. The mixing had to be thorough, with no small lumps remaining. Before application, I'd sand off rust and grease stains from the car paint with sandpaper, then apply thin layers at a 30-degree angle with a spreader. After letting it dry thoroughly for half a day, I'd wet-sand it with 400-grit sandpaper – being careful not to press too hard to avoid exposing bare metal. This method worked decently for small dents but couldn't handle major depressions, and the filler tended to crack under summer heat. Final advice: Nowadays a can of premixed body filler costs just a few dozen yuan. The homemade version has poor adhesion and is time-consuming – unless you're in a real pinch, store-bought filler is much more convenient.
