Advice about nickel plating please

[Barry Kirsten]

A friend recently gave me a Meopta 5x7 enlarger which although fully functional, I'd like to spruce up a bit. It's a beautiful piece of work, made in the days when things were really well built. The column consists of three steel rods which were originally chrome plated. The lens focusing mechanism centers around another rod, also chromed.

I'd like to re-plate these four rods with nickel, because: a) the nickel process is simpler as I understand it, compared with chrome; and b) I don't think the wear factor is such that chrome is warranted over nickel, since nickel itself is fairly durable.

If anyone has done large scale nickel plating, can you advise me on the practicalities involved? For example, the three rods that form the column are about 1.3m in length, so how many anode pieces would be required on each side of the bath? I envisage plating only one rod at a time, so what voltage and current would be required?

I understand that cleanliness is essential and I intend taking back the surface to bare metal, with an acid etch before plating. The pic gives an idea of the pieces. The unit is magnificent... the condenser glass weighs in at 8kg and is 24cm diameter. Thanks for any thoughts.

[Ron in Arcata California]

I have done a fair amount plating. Best advice is to find a professional shop if all you need is four rods plated because of the size of the pieces. Small pieces like screws are real easy, but long skinny items get tricky. Then there is the problem of leftover chemistry that requires proper disposal. My Watt's plating solution has lasted for years however. Besides the main plating bath, you also will need an acid pickling bath and a strong degreasing bath. All said and done, I enjoy plating but it does require a lot set up.

How about replacing the original rods with stainless steel? It would be a cheaper solution and look almost the same.

But if you are like me, it is the challenge and reward of doing something most people wouldn't think of trying. For me the big job yet to be done are the bumpers and radiator shell on my Model A Ford. I have already completed all the other parts including silver plating the headlight reflectors.

Start small but think big.

Ron Klein

[Tin Can]

Your location/country may still have many chome tanks for car bumpers

Up to 15 years ago Chicago had many

I would go to the back alley door and get anything done for cheap

Prep is paramount

I bought 48"X 5/8" rods from Amazon recently

or use eBay

[LabRat]

The other thing to be concerned about is the thickness of the plating... Parts to be plated are slightly undersized, then the plating builds up to the exact size that will still fit the bearings the rods will fit into...

A professional plater is the wise move, and they can determine the proper plating thickness, and properly prep the rods...

Bright plating can introduce reflections from column that can show up on prints, esp with larger blowups if there is light leakage from head...

If the old plating is somewhat intact, rust blobs can be removed with a good polish, where the source of the blob was just a pinpoint void in the plating where the blob came out (like a volcano)... Use an anti-rust metal cleaner, followed with auto rubbing compound (do not use abrasive paper, this can damage the existing plating!!!)

Try this first...

Steve K

[Neal Chaves]

Here is a reliable supplier I have used. They don't have stainless rod, but a thick wall tubing will be very strong.
https://www.onlinemetals.com/en/buy/stainless-steel-round-tube

I have also ordered from Speedy Metals several times. Excellent supplier. They have stainless rod.
https://www.speedymetals.com/c-8266-round.aspx

[Bernice Loui]

Bright chrome was primary a decorative finish. Chrome plating is pours and why it has a tendency to develop rust or similar corrosion under the chrome plating. Metals (steel) is often copper plated then nickel plated to seal the base metal to prevent base metal rust/corrosion before the decorative chrome plating is applied. There are other serious problems with chrome plating such as hydrogen embrittlement.. not really relevant to this need.

The nickel plating to use is Electroless Nickel Plating (ENP). This is the modern solution to a long standing metal finishing problem. Many advantages, fewer negatives.
https://www.surfacetechnology.co.uk/blog-18-everything-you-need-to-know-about-electroless-nickel-plating/#:~:text=Electroless%20Nickel%20Plating%20(ENP)%20is,containing%202%20to%2014%25%20phosphorus.

Discuss this need with your local plating shop.


Alternative is to replace the rods with stainless steel shafting. Being a non-USA made enlarger, they will likely be metric dimension/sizing. Metric dimension/size stainless steel shafting is a off the shelf item from industrial suppliers like McMaster Carr.
https://www.mcmaster.com/rotary-shafts/system-of-measurement~metric/rotary-shafts-5/material~stainless-steel/

Some machine work on raw shafting likely needed.


Bernice

[Drew Wiley]

Nickel is soft and tarnishes rather easily, esp in salt air climates like I live in. It's always been the cheapo option. But either way - chrome or nickel - if your enlarger sits in the same room as the sink and chemicals, you're going to have to periodically wipe down the rods with a protective lubricant or you might get corrosion. 300-grade Stainless is a way better option.

Anytime I've needed plating the secret was to be patient, and just wait for a big job to come in which recouped the plater their time and profit, when my little supplemental amount could be thrown in with the same batch. If sandblasting is necessary first, then that will up the price. Of course, it helped quite a bit that I worked in the same neighborhood and referred a lot of business to them over the years.

[Drew Wiley]

Nickel is soft and tarnishes rather easily, esp in salt air climates like I live in. It's always been the cheapo option. But either way - chrome or nickel - if your enlarger sits in the same room as the sink and chemicals, you're going to have to periodically wipe down the rods with a protective lubricant or you might get corrosion. 300-grade Stainless is a way better option.

Anytime I've needed plating the secret was to be patient, and just wait for a big job to come in which recouped the plater their time and profit, when my little supplemental amount could be thrown in with the same batch. If sandblasting is necessary first, then that will up the price. Of course, it helped quite a bit that I worked in the same neighborhood and referred a lot of business to them over the years.

Reflections can be controlled by something flat black being placed in front of the metal elements. Even black chrome will give off specular reflections, and would probably be too costly anyway. But you might want to rethink this, and simply polish away any tarnish you currently have with something simple like auto chrome polish. That's a fairly inexpensive enlarger in relation to how much you might need to spend to get it fully back to its former glory.

[Bernice Loui]

Specific 316 stainless steel has good corrosion resistance.
https://www.reliance-foundry.com/blog/304-vs-316-stainless-steel

Avoid 400 series stainless steel if corrosion resistance is a requirement.
https://www.ambicasteels.com/blog/300-series-vs-400-series-of-stainless-steel/


Bernice






300-grade Stainless is a way better option.

[Drew Wiley]

303 is a more affordable option to 316 for many applications. Hopefully, no enlarger will be in direct contact with corrosive liquids. I once set up a big designer plumbing showroom back when people would spend thousands of dollars on a single faucet. The same manufacturers of stainless sinks would offer three grades of sinks : the typical cheap home center product, a thin sink made of something barely classifiable as even 18-8 stainless, which will tarnish in about 20 minutes due to lemon juice or ketchup; a much higher priced line of high-quality residential sinks, mostly 303 grade; and then true lab grade 316 stainless sinks, priced accordingly. My own darkroom sink has just basic chrome-plated tall bar faucets because they were given to me as free samples; but they are indeed conspicuously corroded by now.

[ic-racer]

Any plating is very expensive these days. For example I'm restoring a Mercedes 560SL currently. I had about $2000 of plating done over the winter. For example these two pieces were $125 each to be re-plated.
229582

[Tin Can]

https://www.google.com/search?q=560SL&rlz=1C1CHBF_enUS850US850&sourceid=chrome&ie=UTF-8

[Barry Kirsten]

Thanks to everyone for your helpful responses. What I didn't mention is that I have previously had a quote for chrome plating just the three rods of the column - $800 !!! So commercial re-plating is out of the question. The stainless steel option is a good idea, but as Bernice pointed out, machining is needed at both ends, and that will also cost a bit. I'll check that out though. I had a gut feeling that plating big pieces is not easy, that's why I asked. I think that's now out of consideration. I'll have a closer look at the old chrome and see if it can be salvaged as Steve suggested and also consider making new parts. Thanks again everyone.