Can I tig over mig

[DrNik]

If my reinforcement is a bit wobbly can I tig over it to make it flow a bit better and tidy up my welds???
What about the heat implications

 

[dannyp]

i've heard it said your not soposed to but there was no explanation as to why. but haveing run the tig over mig welds before to no apparent ill effect . it's sort of just making it a multi run.
i was told that your not soposed to multi run tig with A15 filler as it can cause porisity, and to use A18 instead for multi runs. bog standard mig wire seems to be A18

i recon it'll be just fine

 

[PSweeney]

If I MIG something which needs to be water tight I use a tig torch to blend in any pin holes, saves tacking and grinding etc. trick is to hit it with high AMPS in a blast to get the mig puddle to move.

 

[Welderpaul]

What are you making?

Multi-run fillets are preferred by welding engineers because each run heat treats and stress relieves the previous.
I suppose it can't harm
(If you're welding nuclear fusion vessels, best ignore the above bit)

 

[DrNik]

I'm only welding 3 mm pipe in different joints, just thought it would look a lot better without having to resort to grinding it all tidy, and worried about the extra heat input

 

[dannyp]

If I MIG something which needs to be water tight I use a tig torch to blend in any pin holes, saves tacking and grinding etc. trick is to hit it with high AMPS in a blast to get the mig puddle to move.

on tanks i often give the corners or any start/stops a blast with the tig just incase