[bigwill (OP)]

I have some perforated sheets of aluminium, about 18"x30", and about 2.5mm thick. I'm trying to make electrostatic loudspeakers with them but the edges of the perforations are too sharp causing corona leakage off of them.

Is it possible to put these sheets in a bath of sodium hydroxide and let it disolve the edges? Is this feasable?

[lightarrow]

I have some perforated sheets of aluminium, about 18"x30", and about 2.5mm thick. I'm trying to make electrostatic loudspeakers with them but the edges of the perforations are too sharp causing corona leakage off of them.

Is it possible to put these sheets in a bath of sodium hydroxide and let it disolve the edges? Is this feasable?

You would also dissolve the rest of Al. Why don't you grind those edges?

[Bored chemist]

I can think of 2 reasons for not grinding them. There are lots and they are too small to get at.
I'd try etching it in NaOH; if that didn't work I'd try HCl but whatever I tried I'd do it on a small test piece first so if it failed I didn't trash anything important.

[bigwill (OP)]

I think I'll experiment with various bits of Al and see what it does.

[ukmicky]

Instead of removing material to smooth out the sharp edges cant you have to the aluminium powder coated or sprayed with some form of paint or lacquer instead

[bigwill (OP)]

Instead of removing material to smooth out the sharp edges cant you have to the aluminium powder coated or sprayed with some form of paint or lacquer instead

I have tried to lacquer the panels but the sharp edges repel it and that is the most important place the lacquer needs to be

[another_someone]

I have tried to lacquer the panels but the sharp edges repel it and that is the most important place the lacquer needs to be

Maybe you could use this to your advantage.

If the sharp edges are repelling the lacquer, then coating the aluminium with lacquer to protect it from acid would help prevent the acid from eroding the main body of the aluminium, while leaving the sharp edges more exposed to the acid.

[lightarrow]

I have tried to lacquer the panels but the sharp edges repel it and that is the most important place the lacquer needs to be

Maybe you could use this to your advantage.

If the sharp edges are repelling the lacquer, then coating the aluminium with lacquer to protect it from acid would help prevent the acid from eroding the main body of the aluminium, while leaving the sharp edges more exposed to the acid.

Genius!  []

[ukmicky]

You need to use an etching primer  but be careful as some which can be used for steel are to strong for aluminum and may need diluting,

[bigwill (OP)]

I have tried to lacquer the panels but the sharp edges repel it and that is the most important place the lacquer needs to be

Maybe you could use this to your advantage.

If the sharp edges are repelling the lacquer, then coating the aluminium with lacquer to protect it from acid would help prevent the acid from eroding the main body of the aluminium, while leaving the sharp edges more exposed to the acid.

Clever!!