in need of some quick advice on an oxidized ZWB3

[Fandyus]

I pulled out my ZWB3 today for some experiments and noticed that one side was extremely cloudy, the other side was cloudy as well as full of stripes/scratches which looked like someone put the filter in a box with a bunch of nails and other sharp metal objects and shook it violently. Tried cleaning it with water and wiping with toilet paper, no success. I have some 3% hydrogen peroxide. Should I just take a spare lid from a jar and submerge the filter in it for the night? Also when I'm pouring it out, should I use rubber gloves to prevent my skin from coming in contact with the hydrogen peroxide?

 

Edit: After letting it soak and scrubbing it, no visible improvements were achieved. Considering that my hydrogen peroxide was expired, I will get a fresh bottle and try again, if that doesn't work, I will be forced to write the filter off I suppose.

[Andrea B.]

Yes, put the filter into a 3% hydrogen peroxide bath for about 24 hours.

Overnight might not be quite long enough.

 

Then rinse the filter with water and pat dry. Leave the filter out to dry thoroughly.

 

I usually use a glass or glass jar for filter baths.

 

I've never been hurt by 3% hydrogen peroxide. It is used to pour onto small wounds for cleansing.

Of course, you can never go wrong by using gloves because skin sensitivity does vary.

So use them just to be safe because you haven't had prior experience with H₂O₂.

No need to fear it though.

 

[Fandyus]

15 minutes ago, Andrea B. said:

Yes, put the filter into a 3% hydrogen peroxide bath for about 24 hours.

Overnight might not be quite long enough.

 

Then rinse the filter with water and pat dry. Leave the filter out to dry thoroughly.

 

I usually use a glass or glass jar for filter baths.

 

I've never been hurt by 3% hydrogen peroxide. It is used to pour onto small wounds for cleansing.

Of course, you can never go wrong by using gloves because skin sensitivity does vary.

So use them just to be safe because you haven't had prior experience with H₂O₂.

No need to fear it though.

 

I was fearing it more because presumably, the outer layer of the filter will be dissolved in it. But sure, I'll leave it in for longer. Thanks!

[Andrea B.]

The filter glass does not dissolve in hydrogen peroxide.

Instead there is a chemical reaction between the hydrogen peroxide and the unwanted corrosion on the surface of the filter. 

The corrosion dissolves leaving the glass clean in most cases.

 

If such maintenance is not performed regularly for un-coated filter glass,

the corrosion will eventually damage the glass.

 

I'm not sure how long un-coated filter glass lasts. Not all un-coated filter glass is prone to the same kinds of corrosion.
I do know that eventually some filters must be replaced. Even un-coated filters can eventually undergo some kinds of deterioration

which often starts when there is a scratch in the coating, or the coating starts to peel off.

 

Let us know if you were able to get your filter cleaned up!

 

 

 

 

 

 

[Cadmium]

You can soak it as long as you want, the longer the better.

The 3% is what you want, it comes in a light proof bottle for a reason.

Hydrogen peroxide is degraded by light and UV, so put the soaking container in a dark cupboard when soaking. Use a jar type container with a screw on lid.

The 3% hydrogen peroxide is not going to hurt your skin.

When you remove it from the bath, you will have to scrub it while it is still wet with the hydrogen peroxide, so don't wash it off yet.

Use some PEC pads or microfiber cloth to scrub it, look carefully at the surface, keep scrubbing until all the cloudiness goes away.

When you are happy, then you can wash it off with water.

This process will not remove scratches.

Usually visible scratches can't even be removed with cerium oxide.

 

 

[Fandyus]

3 hours ago, Andrea B. said:

The filter glass does not dissolve in hydrogen peroxide.

Instead there is a chemical reaction between the hydrogen peroxide and the unwanted corrosion on the surface of the filter. 

The corrosion dissolves leaving the glass clean in most cases.

 

If such maintenance is not performed regularly for un-coated filter glass,

the corrosion will eventually damage the glass.

 

I'm not sure how long un-coated filter glass lasts. Not all un-coated filter glass is prone to the same kinds of corrosion.
I do know that eventually some filters must be replaced. Even un-coated filters can eventually undergo some kinds of deterioration

which often starts when there is a scratch in the coating, or the coating starts to peel off.

 

Let us know if you were able to get your filter cleaned up!

 

 

 

 

 

 

I will, thanks for the tips.

[Fandyus]

1 hour ago, Cadmium said:

You can soak it as long as you want, the longer the better.

The 3% is what you want, it comes in a light proof bottle for a reason.

Hydrogen peroxide is degraded by light and UV, so put the soaking container in a dark cupboard when soaking. Use a jar type container with a screw on lid.

The 3% hydrogen peroxide is not going to hurt your skin.

When you remove it from the bath, you will have to scrub it while it is still wet with the hydrogen peroxide, so don't wash it off yet.

Use some PEC pads or microfiber cloth to scrub it, look carefully at the surface, keep scrubbing until all the cloudiness goes away.

When you are happy, then you can wash it off with water.

This process will not remove scratches.

Usually visible scratches can't even be removed with cerium oxide.

 

 

Thanks for the tips. I don't know about the "scratches". They look like such but the filter has never came in contact with something that could have actually done such damage, I just assumed these were crystals or such. I hope I can scrub them off tomorrow. The peroxide is one month expired but has never been opened mind you. So if this doesn't work I might get a fresh bottle.

[Cadmium]

I don't know about the scratches. There are sometimes crystals in filter glass, those can not be removed in any way, usually such glass is discarded.

I don't know about your expiration date. I would get a fresh bottle, the 3% hydrogen peroxide is very inexpensive.

 

[Doug A]

12 hours ago, Andrea B. said:

 

 

If such maintenance is not performed regularly for un-coated filter glass,

the corrosion will eventually damage the glass.

 

Are we supposed to do this before there is any visible degradation?

Now I have The Sisters of Mercy "This Corrosion" song in my head .

 

 

 

 

 

 

 

 

 

[Andy Perrin]

Nah, you can wait till you see it. It takes a while to mess up the glass. 

[Andrea B.]

I check the filter glass at least twice a year. Usually in spring before I begin to use it again. And in the fall.

 

Usually, but not always, the first thing you see is a slight cloudiness when the light reflects off the filter.

(Look for other topics about this on UVP.)

 

This spring (2021) I poured the entire bottle of H₂O₂ into a glass jar and put every BG filter I had into the bath.  And simultaneously I ran a U and UG glass H₂O₂ bath. Not every U or UG filter is prone to corrosion, but I figured it wouldn't hurt them to get clean anyway.

 

************

 

Doug, thx for giving us a filter corrosion theme song  !!!