Are you guys pushing your filler rod into your weld puddle and moving, or dabbing the filler into the puddle and moving?

I'm currently welding some SCH10 stainless pipe. I have ground knife edge bevels with no gaps between pipes. I am finding it hard to get the weld to be level with the pipe either side and am ending up with a concave weld.

I have tried to push and force the filler into the puddle, but this causes the puddle to become unstable and move about a lot. I have also tried bigger filler rods but they end up sticking when dabbing into the puddle.

 

Are you back purging the stainless? I sinking/concave weld is indicative of poor/no purge and resulting in sugaring the root of the weld.

 

Yep I am backpurging and getting good penetration with no sugaring.

I don't think the weld is sinking, I'm just finding it difficult filling the valley created by the bevel between 2 pipes .

 

dont cut the taper as much. I started running a narrow but sharp bevel. with a 1/16 filler, you dont have to make a 2nd pass. smaller gap to fill. run 60-70A and it filled nicely.

after making a sch10 manifold, it is absolutely ridiculous how heavy they are. using the material is nice to keep manifolds cost effective but man the difference between that and .065 321ss is just night and day. of course the cost is much different as well but this one i made isnt even finished and its a boat anchor.

 

Ahh - in that case I would recommend making 2 passes. What filler diameter are you using? Try a narrower bevel angle if you find you cannot sufficiently fill & cap. A single pass can be done with 3/32 - if the puddle is getting squirrelly I would increase travel speed/adjust torch angle, or heat.

 

don't have such an aggressive bevel and you will beable to fill it with a single pass...some like to do a root pass with no filler, weaving from side to side, then cap with a filler pass

 

Just push more rod in if your bevel is wide. 1 pass is enough on Sch10 imo.