1. The inner cavity should be penetrated with wood blocks and filled, and then the bent aluminum square tube should be shaped, so that it can be protected while straightening. Wrinkles on the outer surface can be welded and polished, and if it is sprayed, it needs scraping pretreatment.

2, serious bending, you can try to cut from the bend, plastic filler on the port, and finally welding, but these are undoubtedly more laborious and the success rate is not high, and the strength will be discounted.