In article , Andrew Gabriel
writes
In article ,
"Sheila :-D" writes:
What's the best way of getting rust marks off brickwork?
Is it just a case of using a wire brush and elbow grease or is there a

No - wire brush will leave more metal on the brickwork, which then goes
rusty (if it's steel brush) making it worse.

solution that will help?

Acids would probably work, but might damage the mortar (particularly
if it contains lime). Many years ago, I recall buying a rust dissolver
for preparing rusty car bodywork for repair -- that might work but
test on a small area of brickwork and mortar for bad effects first.
A rust stain remover might work.

Isn't oxalic acid the thing for this? I think that's what rust stain
remover is.
--
Tim Mitchell