Can I weld this pipe or does it need special prep?

Aluminum can be welded, but it requires TIG or specialized aluminum welding equipment and technique — standard MIG welding won't work. If you're not experienced with aluminum, have a shop handle the joints. The black finish should be cleaned or sanded before welding for best results.

Will this pipe handle high-temperature exhaust, or is it intake-only?

Mounting method and temperature rating are not specified — confirm your application before purchase. For exhaust systems with sustained high heat, verify that aluminum tolerances work for your setup. Intake applications are straightforward; exhaust requires testing or professional guidance on heat shielding.

Do I need to seal or paint the outside before installing?

The black finish is ready to install as-is. If you want to paint or coat it, lightly sand the surface first to help adhesion. No primer or specific prep is required unless you're applying a custom finish — in that case, standard automotive paint prep applies.