Its a cheap flux core welder, so its just typical flux core splatter.

I have some patches I welded on my fenders well over a year ago and have left them bare metal in my garage and there are no signs at all of any rust forming on either side of the welds.
I think as long as I clean the metal good & coat with POR-15 it will be OK.

1957 Chevrolet 1/2-ton Stepside LB in the Gallery
My Photobucket shots

The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself." - John Stuart Mill (1806 - 1873)