[Braehill]

I think if you placed these higher volume units above where you're working that they would have little effect on your cover gas.

Argon, which is heavier than air is going to go down initially then rise after it has been heated. The fumes from the welding itself is lighter than air so it's going to rise from the get go.

The reason for a downdraft table is to pull these gases down and away from the person welding. If you go from above, you should place off to the side and not directly above the table to pull the fumes away from the person welding.

Len


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[450dualsport]

If you had a table that did not have a solid top, do you think the Harbor Freight unit would work OK if it was placed on the floor under the table or would it still pull too much air?

[Braehill]

I would think anything that has a draft that's enough to move the fumes away from the welder in a downdraft situation would have an effect on the cover gas, the fumes are trying to rise and you are trying to overcome that. I personally wouldn't use a downdraft table for Tig welding and I don't have enough experience with Mig to know.

Len

[450dualsport]

That makes sense. I guess that's why you see pictures of fume extractors with the flexible intakes positioned over the work piece.