i just reached blue science and have successfully crafted an oil refinery. welders do have a recipe for [[corrosion resistant, heavy load bearing large paneling]]. it is on the fith row, and is the only recipe in that row (at least at this point in the game).
the tooltip for [[galvanised steel sheet stock]], which is required to make [[corrosion resistant heavy load bearing large paneling]] incorrectly reports that it can be made in a roller. it is in fact made in an electroplater.
i was able to craft an oil refinery and a chemical plant.
the mod was last updated 21 days ago, so i don't think there's been a fix to this issue. is it possible you didn't notice the item you were looking for in the welder's recipe list?
if it helps, here's a handfed blueprint that worked for me:
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
the ovens are there to tell you which machines to handfeed, i don't expect you to be running around with ore in your pocket.