Copy Cad beginners problems

[PeterMorley]

I'm using the setting Caswell Europe suggest (0.14A & 90F)

Anyway I tested three similar samples today - 3" lengths of steel tube that had a surface area of 5.65 sq in.

Used a second heater to get the temperature up - was 35 centigrade (95F), and the parts were warmer than that from the cleaning dip.

Plated them all for 20 minutes at the following settings:
0.56A, 0.68A, 0.79A
That covers 0.1 to 0.14A per sq in.

Results were all very similar, part plated but was covered in a grey layer that looks very similar to grey primer from a spray can (similar thickness too).

It took at least 5 minutes for the acid dip to remove this layer.

Part after plating:
http://users.pandora.be/peter.morley...s/Plating1.jpg

Close up of the grey finish:
http://users.pandora.be/peter.morley...s/Plating2.jpg

Part after 5 mins in acid bath - still some trace of the grey layer:
http://users.pandora.be/peter.morley...s/Plating3.jpg

Also tried one with brightener and no noticeable effect.
It still seems to me that there is something contaminating the surface finish, no one else mentions having to do so much work to reach the plating.

[seanc]

Peter:

I'm using the setting Caswell Europe suggest (0.14A & 90F)

In that case, there is a major discrepancy between UK & US instructions. I strongly suggest you contact Caswell technical support and get the numbers sorted out definitively. I do not have Caswell Europe manual, so don't know how to advise you further.

However, I have visited Caswell UK web site, and it appears to have contradictory information:

They claim it is the "new formula", but specify 30ºC & 25 mA/sq-in, which are the figures from the OLD formula.

The kit is supplied with "Copy Cad/Zinc Crystals with Activator (New Formulation)". There is no "activator" used in the US kit, so it may be that the chemicals are significantly different. If that is the case, then my advise may be worthless. Contact Caswell technical support and sort it out.

It took at least 5 minutes for the acid dip to remove this layer.

That's clearly too long, it shouldn't take more than a few seconds. So something is definitely amiss.

no one else mentions having to do so much work to reach the plating.

Once you've got the process worked out, it is not hard at all, and you should not be having these difficulties.

If you do suspect contamination of the electrolyte, filter it and try again. But in any case, contact Caswell & get the numbers sorted out.

Sean

[PeterMorley]

I strongly suggest you contact Caswell technical support and get the numbers sorted out definitively. I do not have Caswell Europe manual, so don't know how to advise you further.

I had already done so and we went through all the numbers and agreed they were right.

The kit is supplied with "Copy Cad/Zinc Crystals with Activator (New Formulation)". There is no "activator" used in the US kit, so it may be that the chemicals are significantly different. If that is the case, then my advise may be worthless. Contact Caswell technical support and sort it out.

Did also question this because the solution just came as one bottle (which was seperated out) they confirmed the activator is already mixed in this solution.

Once you've got the process worked out, it is not hard at all, and you should not be having these difficulties.

That is what I thought, which is why the whole thing is so frustrating, it is only basic chemistry after all.

Thanks
Peter

[seanc]

I had already done so and we went through all the numbers and agreed they were right.

Then I am at a loss. Those numbers do not match either US formula, so the UK formula must be different for some reason.

What did Caswell suggest?

Sean

[PeterMorley]

Caswell UK was going to check with the US, but I didn't hear back from him.

I'll chase them up next week - I'm thinking that the easiest solution will be to get a new bottle of solution, as well as an extra zinc anode to allow for larger surfaces.