Do I need to go to bare metal?

Quick question, just about to respray my defender and wondering if I need to go to bare metal? the paint on there is faded, some is peeling, some is bubbled, and in the rear its multi layered, awful quality chipping right off, do I need to take her all down to bare metal or whats the best route? if so what would I use, heard sanders/grinders can cause warping and be a massive ball ache

Thanks!

Get an orbital sander, take off as much old paint as you can, pay attention to the flaky/bubbled areas, give it 2-3 good coats of 2 pack primer, not rattle cans, invest in a compressor or pay a body shop to do it, rub that down and your good to go for paint that will last another 50 years if washed and waxed regularly. No doubt someone will tell you to use a roller and a brush which does work depends what your going for tho, daily runner or a off road weekend bit of fun!

Bucket of tar and a yard brush....

Thanks! I'm actually investing in a compresor, but I was just going to use a 1 pack etch primer thinned down in the bare metal areas on the alluminium, dont know if it will react with current paint though, and anti corrosive primer for steel parts, any advice regarding the etch primer and it reacting? I would like to just use it all over really so the top coat will get better advesion rather than sticking to crap old paint