▁the ▁bare ▁metal ▁surfaces ▁bond , ▁and ▁the ▁un - b ond ed ▁portion ▁can ▁be ▁infl ated ▁if ▁the ▁sheet ▁is ▁he ated ▁and ▁the ▁co ating ▁v apor izes . ▁This ▁is ▁used ▁to ▁make ▁heat ▁ex ch angers ▁for ▁re fr iger ation ▁equipment . ▁ ▁Ex pl os ive ▁w eld ing ▁ ▁In ▁explos ive ▁w eld ing , ▁the ▁pressure ▁to ▁bond ▁the ▁two ▁layers ▁is ▁provided ▁by ▁det on ation ▁of ▁a ▁sheet ▁of ▁chemical ▁explos ive . ▁No ▁heat - aff ected ▁zone ▁is ▁produced ▁in ▁the ▁bond ▁between ▁met als . ▁ ▁The ▁explos ion ▁propag ates ▁across ▁the ▁sheet , ▁which ▁tends ▁to ▁exp el ▁imp ur ities ▁and ▁ox ides ▁from ▁between ▁the ▁sheets . ▁ ▁Pie ces ▁up ▁to ▁ 4 ▁x ▁ 1 6 ▁metres ▁can ▁be ▁manufact ured . ▁ ▁The ▁process ▁is ▁useful ▁for ▁cl adding ▁metal ▁sheets ▁with ▁a ▁cor ros ion - res istant ▁layer . ▁ ▁Las er ▁cl adding ▁ ▁Las er ▁cl adding ▁is ▁a ▁method ▁of ▁depos iting ▁material ▁by ▁which ▁a ▁pow der ed ▁or ▁wire ▁feed stock ▁material ▁is ▁m elt ed ▁and ▁cons olid ated ▁by ▁use ▁of ▁a ▁las er ▁in ▁order ▁to ▁coat ▁part ▁of ▁a ▁substr ate ▁or ▁fabric ate ▁a ▁near - net ▁shape ▁part ▁( add itive ▁manufact uring ▁technology ) ▁. ▁ ▁It ▁is ▁often ▁used ▁to ▁improve ▁mechanical ▁properties ▁or ▁increase ▁cor ros ion ▁resistance , ▁repair ▁worn ▁out ▁parts , ▁and