Electroplating questions

[BaldricParticipant @baldric]

I am considering copper electroplating a cast brass chimney cap, looking at the ENV aero engine (part 5) in Model engineer 2018, 2nd March, I can get an idea of what I need to do to get a reasonable thickness.

I will need to solder the cap on to the chimney, so the question comes as it if the platting will stand up to soldering or if I need to solder the chimney first and accept that parts of the chimney will get plated or that I will need to mask them off in some way?

The other options I can think of are to spin a cap, never done that before, or I could have a go at electro-forming the whole cap on some of former, as I have the cast cap already, I was thing on using that, just I don’t like the colour.

Thanks in advance.

Mark Baldry.

[bernard towersParticipant @bernardtowers37738]

If you spin a two piece one its quite simple especially in copper as when freshly annealed its as soft as butter.

[noel shelleyParticipant @noelshelley55608]

The cost of setting up for plating Etc Why not machine from solid or form a ring and then machine the profile. If all you want is the colour dunk the VERY clean brass casting in copper sulphate to coat it – it will soon be sooty ! Noel.

[BaldricParticipant @baldric]

Following comments from people, I thought I would try spinning, also having been to Weeting rally last weekend I felt the casting was also to large. I 3D printed a former, with 50% infill for strength, but low quality, it still took 9 hours to print. I ordered a few 0.5mm discs, annealed one and had a go at spinning. I bit of a bodge for the tool post, if I was doing more, I would make something better.

For some reason the former didn’t spin true, I should have put it in the 4-jaw, but didn’t, this caused an issue when I trimmed the end where it picket up, but recoverable, with a bit of filing.

After a bit of cleaning up the edge with a file, this is the result of the top half, with enough material to fold over the bottom half. It is sat on the original casting.

Once I have done the bottom half, I will decide if I am happy with it, I may remake it in 0.8mm copper if it doesn’t seem solid enough.

Mark.

[Howard LewisParticipant @howardlewis46836]

If you did decide to make in two parts, soft solder is unlikely to withstand the plating process.

(Our plating shop would not consider anything united bt soft solder, only silver soldered or brazed.)

Even if it did, if any shows, it will look different from the copper body / plate.

Brazing would be a better way of uniting the two different metals

Copper Sulphate will be a good electrolyte, from which to electroplate.

Howard

[bernard towersParticipant @bernardtowers37738]

Well done its amazing how when you need to you can.

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