I've used them together but I noticed no better results with the ammonia than without, bicarb on its own did the same job. Obviously wouldn't let either loose on a semi numi or numi coin though.
I needed to leave the really dirty coins in cloudy ammonia for at least 12 hours. It made a huge difference.
For real (not semi) numismatics. Usually numismatics don't come in bulk anyway, bulk and rare tend to exclude eachother.
black is tarnish, sulphur + silver molecules, tinfoil+baking soda+high temperature makes the sulphur to detach again. I don't think it matters whether or not it was cleaned before. You word it abit weird, alike you bleach it and in a short time goes black again. Maybe the temperature dropped too much while you were busy with it? I have the experience that if it's alot coins in one time so you're longer busy picking them out, that the last ones quickly become yellow, and in the case of coins that were originally in a fairly good condition, that they became worser. So it's a matter of limiting amounts to those you can handle in time.
These are circulated round 1966 50 cent coins. There's tens of millions of them and cleaning does not alter the premium. Its just nice to do sometimes. They come up very nice.
I just cleaned 50 50's I didn't have ammonia so I put them in a commercial dishwasher without the chemcials feeding in, that got rid of most of the smeg, Then good ole bi carb massage, amazing how well they came up...
I did the cloudy ammonia and bi-carb and was amazed at how well it works with minimal/no coin damage. Many thanks to House.
This time I left them in cloudy ammonia for 48 hours, and the dirtier ones requires substantial time rubbing with bi-carb. I made a big mess and my thumbs are sore today.
In the pics above, you can see that the rims on many are still a bit dirty. It's hard to rub clean the reeding.
Toothbrush and bicarb should help the reeding. Either that or you put a microfibre cloth down and sprinkle bi carb on it and then just rub the edges of the coin through the Bi carb. Takes a while and I soak in cloudy ammonia in between rubs to keep loosening the grease.
Hmm, Pete Have you been in the military? A soldier would be ask to scrub the floor with a Tooth Brush. Maybe a tooth brush will help brushing those reed
You using your thumbs, no wonder you have sore thumbs Next time just ask around, there are plenty experience members here Now how about a good thumb up
