If you are going to strip fenders to bare metal top side and under side burning is very fast and harms nothing IF you give the heat from the fire an escape route. Don't burn where fire is on the under side. Photos are of a very pricey 55 Nomad that total floor prep time was done in an hour.
Try to burn approximately a 3'x3' section at a time so can be scraped while still bubbling from heat:
[](
https://postimg.cc/JsMvcrQ0)
Much drops off from heat but scrapes off super easy:
[](
https://postimg.cc/7JNMxkJt)
A quick spray with low pressure sand blast leaves surface clean:
[](
https://postimg.cc/QVBFhs1F)
