Triumphrat

RII

It's "Mr. Knuckle-dragger" to you sir!
If PH is a concern, you can always test the bath with simple PH dip strips...
Interesting discussion/information, may pursue plating at my next tear down (hopefully a good ways off)....

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A GOOD friend will bail you out of jail, a TRUE friend is sitting on the bench next to you saying "Damn, that was fun!".

Snakeoil

All my tongue in cheek comments aside, I have to say that this DIY zinc plating is one of the best things I've come across. I've plated the various bits on two motorcycles and one has been run in 3 motorgiros and the plating still looks as good as the day I did it. That includes two sets of spokes on the one bike.

The only issued I've had with the vinegar and Epsom salts bath is it gets very dark with time and you cannot see the parts or the bubbles. I use the bubbles as a indication of good electrical contact.

I'd like to find something to replace the sugar as a brightener due to the sticky nature of the bath with sugar in it. Not sure the gelatin would be any less sticky. The sugar collects on the hangers and the main hanging wire over the bucket and makes for crummy electrical contact after a while.

Any ideas for replacing the sugar?

regards,
Rob

ed_h

Rob--

I've asked the same question and have done a little research off and on over the last couple of years to try to find the holy grail of brighteners.

Most commercial operations use chemistries with proprietary brighteners, so it's a trade secret what they are.

Another route is to look at some of the patents for brighteners. This is more fruitful, but still fairly useless, since most of these are pretty exotic chemicals that don't show up in traditional lab chemical suppliers' catalogs.

Of the few I've found in patents or elsewhere that can be gotten from lab suppliers, mostly the price has just been too high to take the plunge.

There are some fairly simple substances, however, that come down through plating lore. Among them:

Gelatin
Various sugars (glucose, sucrose, dextrose)
Molasses
Benzalehyde
EDTA (This is sold as a health supplement, but it's usually not in pure form)
Tobacco juice

If I ever get more leisure time, I'd like to experiment more, but for now the gelatin gives me predictable results. There is very little of it in my bath (less than 2 grams/gal), so I haven't noticed the stickiness problem.

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Snakeoil

Thanks Ed. I'm going to try gelatin then. I just had to tear my setup apart and wash everything in hot water. It was so coated with sugar that I could not make reliable electrical connections.

It was kinda like my face and hands would look after eating a popsicle as a kid.

regards,
Rob

ed_h

Cool.

Since I've only ever used gelatin, I'll be interested to know if you notice any difference.

Ed

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For only a little more, you can do it yourself!

Acebars

I was thinking about just this subject. There are good reviews and results on gelatine. Unfortunately the composition of brighteners is quite a guarded subject.

Some good reading here:


http://scialert.net/fulltext/?doi=ajaps.2012.314.326&org=12

Ethyl vanillin and Cetrimonium bromide (cetyltrimethylammonium bromide) both have visibly excellent results for zinc plating, bright plating (see Fig 7).

Ethyl Vanillin is used in chocolate making and can be bought pure on ebay similar but not identical to vanilla sugar. CATB is used in hair conditioning and can also be bought on ebay. Its actually quite cheap to buy very small amounts, around 25g and 50g for £12 from the US.

These will electroplate bright zinc according to the study.

This is also great and shows some already done experiments:

http://jcsp.org.pk/index.php/jcsp/ar...wFile/1210/806

Indeed of all the tests done only vanillin (vanilla sugar you can buy in a food store) produce a bright deposit and maybe a cheap suitable alternative to ethyl vanillin, experimentation awaits!

Snakeoil

Good stuff, Ace. I looked over them quickly. Need to read them completely. I see gelatin mentioned and the results look good.

Based on what is said about glucose providing a powdery gray surface, I think the goal of the brightener is to have the plate be bright right out of the bath. I have to wire brush my parts to remove the gray and produce a bright finish.

Now I'm really curious how a bath with no brightener would work.

regards,
Rob

Snakeoil

Mixed up a new batch of plating bath today. Instead of sugar, I put 8 oz of Epsom salts and 1-7gm packet of Knox gelatin into 2 quarts of white vinegar. Tossed in a couple pieces of zinc to dissolve in the bath overnight. Will do some plating tomorrow and report the results.

I'm really looking forward to a bath that is not sticky.

regards,
Rob

Snakeoil

Ed,

Plated a part today and don't like the result. The positive outcome is it comes out the the bath with no brushing required. But, the color is more of a pewter color than bright zinc. Since I'm in the middle of a resto, I did not want to experiment further and dumped the solution and made a new one with 8 oz of salts and suger to 2 quarts of vinegar. It is sitting with some zinc in it right now so it will be ready to go tomorrow.

I also found the gelatin bath to be a bit foamy. Bubbles looked more like particles, but then disappeared when they hit the surface. Could be I used to much gelatin as you said you use only a small amount of 2 gm/gal. The above mentioned article said gelatin quanties vary between 0.1 to 20 gm/liter. That's a huge range. So since the packet was 7 grams, I just dumped in a full packet.

Maybe when I get caught up, I'll make a smaller plating container so I can can make up small quantities of test baths and see how each performs. Not having to brush the parts after plating is a big plus when you are doing lots of small parts. If I can get that result and the bright silver color I'll be really happy.

regards,
Rob

Ohio-Rider

Hey Rob,
I’ve got 4oz. of zinc brightener in an unopened bottle I got a few years ago from Caswell, it says to use 1/2tsp of it for 1.5 gallons of soup. It’s your for the asking, PM me your interested. I never used it because most of the stuff I plate, I’m looking for more of a dull cad finish.
Steve