What does Brush On Weld mean?

Brush On Weld meaning in Urban Dictionary

whilst the name indicates, this will be a weld that it brushed on. It is used by the 'clever' DIY'er to 'fix' holes in automobiles which will usually fail roadworthyness test. Brush on weld takes the form of either underseal or seam sealer. Since it is much simpler to put on than a proper material weld, in that it doesnt really join any steel collectively, it's in the understanding on most spanner monkeys.