From a welding standpoint the root pass is much more difficult uphill, but it is recommended (by me
![grin :grin:](/f2/epx.png)
), that if fill passes are to be done, (not recommended by me
![grin :grin:](/f2/epx.png)
) they should be uphill.
It is very difficult to control the heat in an uphill short circuit open root. Done it. Not easy. While on the other hand due to fusion difficulties the additional heat is an asset in fill passes.
Given your question I would venture to guess that you are not ready for uphill roots or fill passes period. Not meaning this as an insult.
SST and associated technologies are very helpful here. This is actually (despite all the marketing bullshyt associated with these technologies) the place where they really shine. Especially on high alloys.