This may compromise the energy and integrity from the joint. To avoid porosity, take out the zinc coating in the weld location. Spot a coupling bolt on Just about every bolt gap and tighten the coupling bolts using a wrench or socket wrench. Make certain to tighten the bolts evenly. https://www.malleableiron-pipefitting.com/industry-knowledge/how-to-connect-non-threaded-galvanized-pipes.html