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Buffing Parts Before Plating

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Modified on 2008/04/02 09:03 by krucker Categorized as Restoration Topics
By Peter Crowl


Introduction

$295 for the whole lot. Urp! That's more than I paid for the whole machine! But when you're standing at the counter at the chrome platers, nothing should seem to outlandish. Chrome Plating and Aluminum Polishing are the things most people look forward to in the restoration process. You unwrap the new shiny parts and you can almost imagine that you're a poorly paid assembly line worker building yet another lathe. Wait - that's not very romantic- I mean a wealthy collector building a brand new machine from the ground up. Ground-up, however, is how you feel when handed the bill. There is an alternative.

I got the above mentioned lot of parts done for $75 even. That's for plating the steel / brass parts and buffing the aluminum pieces. Discount Plater? No, I buffed and polished the parts myself. And you can too. You will need a certain amount of equipment and some supplies and that will mitigate the savings on the first job, but if you intend to do more than one machine (and I think that means most of us) it's worth it.

There are two distinct jobs. Polishing and buffing. Polishing is working the piece to a point where you can buff it to the mirror-like gloss you want to have before going to the plater.

Let's look first at what you'll have to acquire to do the job. (Oh Darn!- another excuse to scour the Classifieds for stuff to buy!)

It's actually a short list: A MOTOR to turn the BUFFING WHEEL which carries COMPOUNDS to remove the imperfections in the metal. Easy Huh? This and some safety gear and your set.

The Motor

You'll need a motor. If you can swing it, get a 3/4 hp motor or 1/2hp at least. 1/4 hp will do for small jobs if you're very patient. There are single and double ended motors. Double end units are convenient since you can run 2 different buffs at the same time. On a single end unit you have to stop and change wheels. BUT for the difference in cost you can usually find a way to live with a single end. The key thing about any motor is that it be enclosed and fan cooled. Open motors accumulate dust which can cause overheating and shorten motor life. The motor you find will probably not have a threaded shaft so you'll want a work arbor which attaches to the shaft. There is a double benefit in that this arbor moves the buff out and gives you more work room.

There are charts that tell you what width of buff you can lay up on what size motor. Buffs are usually about 1" wide so you gang several to get your desired area. Fact is unless you're doing custom work and want to chrome plate your side covers, you'll only need 1 or 2 inches of buff. Any of the above mentioned motors will handle that in 6" or 8" diameters.

How fast? I thought I'd need 3600 RPM for buffing. As it turns out, 1,800 RPM is just fine. The slower speed even has an advantage in that ruffle buffs, which are open weave and designed to cool better and conform to odd surfaces, resemble solid wheels at 3,600. It's too fast. The good news here is that 1,800 RPM motors are MUCH less expensive. By the way, think about a pedestal while you're looking for the a motor. Plunking it down on the bench isn't the best option since you need room to work around the wheel. 4" pipe with floor flanges bolted to a large tire rim is a time honored tradition where I come from.

There are also some creative options.

  • Electric drills - they work but can run hot if used continuously. Best used for touch -up or very small work.

  • Bench grinders - OK for small parts where you don't need a lot of clearance between the buff and the motor. Small stainless steel strips, Floor strips, Fuel Tap levers, etc.

  • Dremels, and Die Grinders. - A good choice for tight spots like the fork links on an LI. Dremel tools will require a speed controller, though, since they can run way too fast for our purposes. Plan on using a 1" by 1/2" buff or Felt Bob. (As opposed to a Jim Bob)

Safety Gear

You'll need a face shield (Sears clear full face tilt up model is great), gloves - I use standard work gloves in either cotton or leather (parts get hot) and a dust mask. I'd also recommend a shop apron or coat. When you're done at the wheel you'll be something of a mess. A Note About Gloves and Sleeves: Remember that you're working around a fast moving wheel. Loose clothing and "Strings" hanging off old gloves can get caught up with disastrous results. Be Careful.

That's about it. You can get elaborate and run your shop vac line to the wheel to collect the crud. I'd recommend running a light to the motor so you can see the progress. There is a lot of controversy about imported motors. For as much use as I give a motor in my shop, I can't see why it would make a difference. If I ran a production shop - that would be a different story. As it turns out, I bought American motors anyway. A double end Baldor 3/4 HP motor on a pedestal for $100, barely used from a golf club shop that bought it and then found it to be too big for their work and a Baldor 1/3 hp for $50 at a collector car swap meet. You should be able to scrounge up a similar deal, after all you scrounged up the machine didn't you?

Oh, while you're scrounging, don't pass up a good deal on a 1" upright belt sander. They're great for polishing the rough stuff off before you start to buff - more on this later.

OK now we have the motor. That's easy. The various wheels and compounds are bewildering at best. Let's look at some good choices for our type of jobs.

Compounds

Compound selection strikes fear into most people approaching this job. There are scores of them available. In reality, out of the scores of compounds available on the market, we'll need just 3 to do our work. A compound is nothing more than a bar of lubricant, usually tallow based, that contains an abrasive grit. They're just like sand paper except They're color coded for identification. Here are the ones we'll need:

The Red One - called Tripoli - is used on aluminum, brass, copper and die cast metal.

The Grey One - is for steel, stainless steel and cast iron

The White One - In the trade final finishing is referred to as "Coloring". This is a "Color" compound, used for final finishing of all the metals we'll encounter. There is also a Green coloring compound that you may want a bit of as well. The grits are slightly different.

If you're lucky enough to have a local supplier of these items, you may want to make a deal for the broken off end chunks of compound. They seem to like to be rid of these and I've gotten them for a good discount. In fact when I've been buying a lot of supplies, they've thrown in some pieces for free. Woodworking machine parts are small jobs and a 3" bit goes a long way.

Wheels

There are basically 3 types; Sewn, Loose Sewn and Ruffle or bias buffs.

Spiral sewn and Concentric sewn .These are the ones used for the initial buffing steps. They present a rather firm surface to the metal yet conform to shallow curves etc. The best are sewn with rows 1/4" apart. This makes for a more dense wheel that will last longer. You get a few of them and stack them together to achieve your desired width. The concentric wheels seem to do better in smaller sizes at high speeds - such as on die grinders or Dremels. Both are good for making the set-up wheels that we'll discuss later.

It must be noted that you should never mix the compounds on a wheel. You have to get a separate buff for each compound. Each compound has it's own grit and to hit a more coarse grit on a fine operation is unpleasant at best. Mark your wheels on the outside surface with a magic marker so you don't mix them up.

Loose Sewn. These are sewn at and near the hub. They are much softer than the spiral sewn and conform to curved and irregular surfaces very well. These wheels need a slower motor - 1,800 rpm is just fine. Any faster and centrifugal force causes them to lock up like a fully sewn buff and what's the point of that? These are the ones to use for color buffing.

Ruffle Buffs. These are, as the name implies, sewn with a ruffle in them. This is for cooler running and these also are an 1,800 RPM wheel. The big advantage here is that they are made of heavier cloth and so work like a spiral sewn wheel . The flange/arbor plate set-up is critical with these. Discuss the options with your dealer! These are available also as "mini Bias" wheels and are handy on a drill or such motor for tight spots.

Finally, you'll need some sort of rake to clean the wheels. A clean, stiff, wire brush dedicated to this application will do just fine.

Equipment Summary

It's all rather obvious. The wheels aren't very expensive and for $30 or so you can get a nice selection to play with. After a while you'll learn which ones work best for you. I use spiral sewn for initial set-up and loose sewn for coloring. I'm still playing with the ruffle buffs to determine how best to employ them. You'll also come across various things like Scotch Brite pads and other nylon type cutting wheels. One came with my 3/4 hp motor and it works great for quick removal of deep scratches. We'll also be looking at making set-up wheels later. If you're into doing restoration work in general, it'll pay for you to set up a comfortable work station to do these operations. Getting Started.

Ok so now we have the equipment and the work station set up. Now what? Well, as with most things, we have to prepare the pieces to be done before we start. First, all pieces must be clean - free from any and all grease, paint, plating and dirt. Plated pieces must be stripped by a plater or metal stripper to get them back to base metal. NOTE: It is tempting to try to buff a chromed piece to achieve a "restored" finish. If Never Dull pads don't shine it to your satisfaction, why not run up a color wheel and have at it? Well, you may actually get a nicer shine BUT you'll be removing the plating. It's easy to cut through to the under layer of nickel and so ruining the finish anyway. Do Not attempt to remove the plating with a wheel as it will not do a good job and will screw up your wheel but good.

Choose the wheel and compound for the job and get to it. There are a few tips but you really have to learn by doing to get good at it. The compound is applied directly to the wheel as it is turning. When applying, do it in small applications. You don't want to load up the wheel or the part with excess compound. Hold the part at about 25 to 35 degrees below the center line of the wheel.. Each time you run up a buff (except for a new one) you must rake it to loosen it up and remove hardened compound.

If you spend a rainy afternoon playing with the combinations, you'll get good at it. Start with an old aluminum kick start lever. Mount up a spiral sewn wheel, coat it with Tripoli (red) compound and go to it. Remember to change the angle at which you hold the part to lessen the chances of setting up a grain pattern. If you keep moving the part as you draw it across the wheel, you'll get a better finish.

Polishing

This is the term used in the trade for the initial set-up or removal of deep scratches etc. Think of it like wood finishing. You start off belt sanding the really rough parts, move on to an orbital to get the piece down to the point where you use an air sander with 600 grit for final preparation. I use the aforementioned belt sander, with the back stop removed so the belt is flexible, running 320 or 400 grit belts. It works great for removing the deep divots. What you're trying to do is remove the deep scratches, replacing them with light ones that buffing will remove.

You can make set-up wheels by gluing loose abrasive to spiral sewn wheels. They act like a drum sander but since they're a cotton buff, they will flex with the part. I'd recommend learning how to do this by obtaining the video tape put out by Bright Works Inc (see source guide). These set-up wheels are used by the professional shops with great success, but they must be done right and space here doesn't allow for the entire description.

Summary

For pre-plating work what you're doing is removing as many of the imperfections as you can so the plater either can go straight to the tanks or at the very most give the part a quick once-over and then plate. This saves you the most money. The part has to look like it has just been plated before it goes in or you won't be happy with the result. The smallest scratches will jump out of plating and hit you right in the eye. I usually have the plater run over the parts justy to be sure they're as good as can be. Buffing out the aluminum is most rewarding since the parts shine-up so nicely. It's really fun to take an old lever or wheel and shine it up like new in 5 or 10 minutes. Try it - you'll see!

Share your experiences! We need you to make these technical pieces work! Also, if you contact the suppliers listed, be sure to tell them you saw them here. They've all been helpful in preparing this piece and they should know their efforts pay off!

Sources:

If you live in or near a large city, look in the yellow pages under Metal Finishing. I've found both our local sources very helpful despite the fact that I'm very small change to them.

Bright Works Inc. offers a detailed guide book as well as a 60 minute video tape which is VERY helpful. You can get both for $29.95. I can't recommend these two enough. They also have a catalog which offers everything you'll need at competitive prices. They also offer "kits" that group the products you'll need for various tasks. Contact them at:

Bright Works Inc.
106 Loretta Ln.
St. Paul, MN, 55115
(612) 429-4439

These folks are my main supplier and have been very helpful to me in the preparation of this material. They ship UPS nationwide.

Metal Finishing Systems
2351 W. Yale
Englewood, CO 80110
303 936-2244
FAX 303 936-1635
1-800 747-2637

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