Surface Roughness

Surface roughness should not matter in any case. Surface cleanliness is critical.

You don't say anything about cleaning after wire brushing.

Please give the entire process, step by step. From the time the plate comes in the door till etching.

the cleaning process have three 3 stages

1) wire brush together with caustic soda and water

2) washing process

3) drying process

the cleaning process have three 3 stages

1) wire brush together with caustic soda and water

2) washing process

3) drying process

PLease,

If you want help, give complete descriptions of washing and drying processes.

The term "washing process" is totally meaningless. You cannot give too much detail.

Do you have process documentation? What do you make?

ok i will come back to you as soon as i get the detail process of the plate

Lynlynch:

Wire brush makes deep scratches at spacing of say 5 per linear mm depending on brush coarseness.

Sanding could be say 100-400-800 grit...

Chance of oxide scale NOT being removed by wirebrush is probably power of ten multiples of that remaining from sanding.

I ABSOLUTELY AGREE WITH YOU ABOUT SURFACE CLEANLINESS, but consider that cleanliness may be a derivative of the chosen process, brush vs sanding, and thus roughness a proxy indicator for ability to etch.

Milo

Milo,

You are the expert. I defer to you.

so we can assume that its better to use a sanders to clean the plate instead of a using a wire brush?to have a better etching result

milo

you mean that sanding is better than wirebrush to remove oxide scale??

If you read my comments above about the brush "wire size and distribution" and that of the sanding material it should be obvious, IF THE processes are under control and the sanding medium is replaced prior to exhaustion.

The best way to remove oxide scale is acid pickling. this is a chemical process and only obstacle would be oil on the material to prevent reaction.

Second is abrasive shot or grit blasting. this is mechanical. Its issues are that it may roughen the surface too much. selection of shot and grit is critical.

Wire brushing Is fine for coarse work. but the non uniformity of the removal rate and the directional "lay" created by the "bielby layers" thrown up by the bristles may be detrimental to your next etching process.

The use of an appropriate sanding paper or two to get first rough removal, then intermerdiate removal, folllowed by a really fine removal will result in best scale removal and the least "clawed up" workpiec.

If yo make a weak solution of copper sulfate, you can use it to test if all the scale is gone. Whereve there is bare steel, it wil lplate out brite copper, it will not do anything where the scale is.

We used this to indicate our shotblasters efficacy and whether or not the dark "shadows" that we saw aon product were scale or not.

Milo

After that come

Have you tried reverse osmosis with DC voltage. Google "rust removal using reverse osmosis". Its not hard to do and cleans rusted metal very good.

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