Polishing Question

I have always just used my flexshaft and abrasive wheels to polish both my silver and gold. I use the 3m bristle discs and the advantage silicon wheels depending on what I am doing. I have never really seen a bench lathe used. But recently I have been hearing more about using a bench lathe and I have seen some reviews where folks mention how much of a time savings it is over using a flex shaft. So can all of you experts give me a bit of advice about a bench lathe and polishing with it compared to using a flex shaft? I see that Rio has a nice little unit with a dust collector from Foredom on sale so I am wondering if it is worth the investment? I really would probably want to use the same media, I don’t have interest in using buffs with compound and I did see that 3M bristle discs come in 3" size to be used on a lathe. Thanks for all of your wonderful advice to someone who is obviously not an expert on polishing.

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image I work at Halstead and we sell this bench polisher at my work plus we have one in the studio. I do a lot of polishing on blanks with it, which really speeds up the process, however, when I’m working with detailed jewelry I use a flex shaft with the 3M bristle disks. They do make a pre-treated wheel for this that does not require a compound. image

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I use both depending on what I am doing and the size of what I am polishing. I don’t make a piece of jewelry that doesn’t see either piece of equipment before it is done. If I only had one, it would be the lathe. I can do by hand what polishing grinding and other operation the flex shaft does, but it would take a lot longer. I have always had a 1/2 - 3/4 HP polishing lathe with tapered spindles and 6" buffs. I keep a separate set of buffs for tripoli and rouge. The buffs are multi-ply treated muslin. My lathes have always run inside a polishing hood that is power ventilated to the outside with some form of filtration that allows me to catch as much precious metal as possible. This is real important because you don’t want to breathe the dust. I also wear a dust mask and eye protection. Gloves have been a topic of discussion in the past. I always wear heavy gloves for tripoli and cotton gloves for rouge. I can’t imagine trying to hold on to anything that I am polishing, especially with tripoli, without gloves as the piece gets very hot. I make fairly large pieces and gloves may not be necessary for smaller pieces, but your hands will get beaten up. Look at the various tool supply catalogs and websites. Call tech support and discuss your needs with them. You can easily spend $1,500 on a hood and lathe. I have always built my hoods and ventilation systems myself, but have always bought as good a lathe as I could afford. Think Baldor and $500. You can; however, start with a motor and spindles that attach by allen set screws, but they tend to have balancing issues. Take a look at the shop shots on my website to see how I have built my polishing hood. It works well for my needs. Good luck…Rob Meixner

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Hi Rob,
I agree that if you’re on a budget, it is easy enough to make yourself a hood for the polishing lathe. I go further than that and use a 3450 rpm motor from a Chinese grinder. These are available new for $50 and used for less than that. Remove the grinding wheels and their protective casings and add two spindles and the polishing wheels you want. I haven’t had any trouble with balance on these, they run quite smoothly for me. I don’t use mine that much, but it is holding up well. Since I’m not using it 24/7, I find it hard to justify using an expensive Baldor motor when the generic motor lasts a good while and is easy to find cheaply.

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Is lower speed the reason you use a Chinese grinder instead of a Chinese polishing machine?

berniejohnsonjunk, I use both because sometimes the flex shaft cannot provide an even finish. Be sure to search the archives on the bench polishing lathe because they are extremely dangerous and you need to fully understand the risk and ways to avoid hurting yourself …seriously.

I never wear gloves, I wrap the tips of my thumbs and fingers with Vet tape … https://www.chewy.com/andover-healthcare-petflex-dog-cat/dp/153249?utm_source=google-product&utm_medium=cpc&utm_campaign=hg&utm_content=Andover%20Healthcare&utm_term=&show-search=1&gclid=EAIaIQobChMIjazIj_OF3gIVj7fACh2b6wXIEAQYAyABEgLH9vD_BwE

I looked at a bench grinder and a buffer at Harbor Freight, and the difference was the horsepower is greater on the grinder than on the buffer. That makes sense, less bogging down when pressure is applied.

You buy what you can afford. I was lucky enough to have a father in the business, so I got my first polishing lathe by painting his house. I have fitted allen set spindles to a common fan motor. You just have to fiddle a bit to get them balanced. Betty - I have tried the tape that you suggest but I just can’t make it work. Leather work gloves are what I use. Yes, I have had my fingers and hand wrenched, sprained and cut from the gloves getting caught on the spindle. I try to prevent this by using a piece of plastic pipe to cover all but the part of the spindle that I need to engage the wheel. If a lot of the tip is exposed, I run a wine bottle cork up it. This way, if the glove, especially cotton glove, contacts the spindle, there is little or no thread to grab it. I have also installed a “kill” or “dead man” foot switch that needs to be stepped on before the motor will spin. If I remove my foot, the motor stops. It is not an instant stop, but it is better than nothing. Regarding Baldor. They are the best, but there are other lathe motors that will do the job just fine. Take a look at Jeffery Herman’s shop pictures and you will see a great polishing setup. My shop is the result of 45 years of research, designing, tweaking, wishing, making mistakes and having a lot of fun. I only ask that the business side pay for it and allow me to keep growing in my art and, of course, being able to more tools…Rob

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My first polishing motor was a 1/4 hp Craftsman motor with a taper. It turned slower than the 1/2 horse I used when I polished at my Dad’s shop. I didn’t have the horse power so I had to learn soldering technique, pre-polish preparation, and hand work. Now my motor is s 1/2 hp Baldor.

I use white cotton leather gloves liners as polishing gloves. The worse Burns I have ever had was from polishing and super heated polish in a saturated leather glove. I limit the possible parts of the polisher that can grab anything. Rubber hose on the motor shaft between the wheel and the housing of the motor. Any taper exposed with the wheel is covered by a 4 x 1 hard felt wheel.

---- Betty2 orchid@ganoksin.com wrote:

My experience with using a Ryobi (made in China) grind wheel as a buffer has been terrible. Absolutely the opposite of yours. The wheels are badly balanced, it throws buffing compound all over the place, makes for a filthy studio (I buff in a separate room) and although I wear a mask when I buff, I still get a lung full. Chinese quality on anything is highly irregular, and on electric motors and buffing and grinding wheels, even more questionable. I’m in Japan where it’s hard to find anything else for a reasonable price, and I look forward to the day when I can throw it in the garbage and buy a Foredom.

HI Bill,
Far be it from me to defend all Chinese manufacturing and I surely don’t know what’s going on in Japan. However, I think you may be conflating several different things here. A badly out of balance motor would be apparent if one started it up before buying. A badly out of balance motor would not be responsible for throwing dirt about the room…that would be the responsibility of the extraction system.OK your Ryobi motor is badly balanced, but IDK what you are saying about the extraction system. I was saying that here in the USA you can find a used Chinese or other vintage motor with which you could build a buffer by adding spindles and wheels and then add a home-built hood and extraction system. Yes, you should start up the motor before buying or get right of return to check balance. If you’re going to save money by building your own extraction system, you need to compare the CFM on your chosen fan with that of some recognized decent commercial system and make sure your design is decent. And so on. I’m not against people buying a commercial system that works, just pointing out that you can save several hundred dollars by DIY. Thx, royjohn

I polish a lot! It’s a big part of my job. (I work at a small jewelry manufacturer.) It does sound like the Foredom lathe with the 3M wheels (3” usually) is a good set up for what you do. The wheels change out quickly and the lathe has variable speed. That’s nice if you’re used to using a flex shaft. If you really got into high mirror finish, you can still use the smaller lathe with cloth buffs and compound. (I recommend Picasso Blue as a great one step compound for a bright mirror finish.) A small lathe will be much faster for you than the flex shaft. There’s no need to go to a large Baldor lathe until or unless you have a lot of high Polishing to do. Foredom is a great reliable brand and they stand behind their products in my experience. Good Luck

Ruthanne

Hi John. All the things you mention are available in the USA, but not in Japan. Unfortunately, I bought this grinder new, and used it as a grinder first. The faults were not apparent, as the grinding wheels concealed how badly out of balance the motor was. When I put buffing spindles on it, I realized how bad it was.

I agree that in the USA you can save money by going DIY. But in the United States, you can get decent quality parts for all the components you need. It’s not possible here. But what I would advise strongly more than anything is getting a well balanced motor. This means buying American. Let’s face it. The only reason to buy Chinese is to save some money. It’s a false economy, because your buffing machine is one of the most important tools in your workshop. Indeed, I think for most jewelers, along with their flex shaft, it’s the only powered tool in their workshop. So buy wisely. Buy quality,

The most important tool in my workshop is the Jool Tool. It makes use of the 3" 3M bristle discs easy and because of the horizontal design, it makes it easy to see what I am doing. I also have a very nice Baldor polishing lathe that I use for tripoli and rouge. However, I find I usually only use the Baldor for a very final polish on a finished piece and my Jool Tool is the work horse.

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From what you’re saying - that the grinding wheels seemed to work okay but the buffs were unbalanced - it sounds like your buffing arbors might be causing the problem. Usually grinding operations are more sensitive to runout than buffing. Check the arbors without any wheels on them. The tool for doing that is a dial indicator, but if you don’t have one just set up a piece of scrap wood or something in a fixed position very close to the end of the arbor. If the gap between the fixed point and the arbor varies as you rotate the spindle shaft by hand, that’s your problem. You can usually fix it by adjusting the set screws that hold the arbor onto the shaft, unless the shaft is actually bent.

The other problems should be dealt with by your extractor and enclosure, as others have mentioned.

Thank you for your suggestions. As a watchmaker, I have some basic training as a machinist (not much, however!) so I know what a dial indicator is, and have one. There is also a small lathe in my office. I used my dial gauge to measure the rotational circularity of the grinder’s arbors without either buffing wheels or grinding wheels attached. They were elliptical. I also measured the arbors themselves with a micrometer, something few jewelers keep handy, and the arbors themselves were sufficiently circular. So the fault lay in the grinding motor itself. Ryobi QC of their Chinese made bench grinders was sloppy and this is a quality issue. Of course this problem was not apparent when there were grinding wheels on the motor as they are quite heavier and tended to mitigate the elliptical motion of the grinder arbors. However when the much lighter buffing wheels were put on it was obvious. Unless one tore down the motor entirely, replaced all the bearings and entirely rebuilt the motor from scratch it was im possible to correct this fault. As you suggest, the buffing arbors were the first place I looked to correct the fault, but with the actual motor arbor turning in an elliptical motion, adjusting the arbor screws was could only do an insufficient amount to compensate for the low quality of the motor itself.

When you buy power tools buy Quality. Buy American. These are the best buffing machines you can buy, and there is a reason for their price.There’s a variety of manufacturers to choose from. Buffing machines are used widely in a variety of industries such as automobile finishing and guitar making, to name just a few. So there are a number of very good quality American manufacturers to supply this market. I thought being in Japan that Ryobi would be a guarantee of quality. It is not, and I would avoid their equipment too . Buy quality. and you will have a trouble free tool that will last you for many years and help you do superior work.

Thank you all for your replies. I went ahead with the Foredom while it was on sale and I have it all set up. I bought the 3m bristle discs, a sunshine polishing buff, and a buff for a satin finish. I haven’t tried it yet, but it sure purrs when you turn it on. I think I am most excited about the dust collection hood. I have had it in the back of my mind that I really need one, so hopefully I will no longer leave gray dust all over the room. Thanks again for all of the great information.

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Hi bernie…I got tired of fiddling with the chuck key and bought the Chinese knock off of the Foredom H20 quick change handpiece. If you’ve been reading here you know that both this knock off and my hammer handpiece knock off both did not fit my flex shaft sleeve and I had to take a small cylinder shaped grinding wheel and ream out the sleeve to get them to fit. That said, after this 20 minute job, the H20 clone works fine. Just hold the handpiece vertical while you sand to try to keep the grit generated out of the bearings, blow it out when you are done and it should be fine. $12 vs about $75 for the real thing. You decide. No more wasted time with the chuck key, which I also lose periodically. royjohn