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Beryllium Copper Sander Shoe

04/11/2010 9:44 AM

I've been trying to sand a surface as perfectly flat as a home tinkerer can with a common electric vibration sander. I've tried putting a piece of veneer between the sand paper and the sander base but soon after turning it on, the veneer either destroys the sand paper where it bends around at the crimping bar or if I cut it shorter, it vibrates out from under the sand paper. I was thinking of having a beryllium copper "shoe" made but before going to the expense of having one made, I was wondering how susceptible to vibration cracking the bent corners would be.

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#1

Re: Beryllium Copper Sander Shoe

04/11/2010 10:45 AM

Try using a belt sander. Beware the dust.

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#5
In reply to #1

Re: Beryllium Copper Sander Shoe

04/11/2010 12:34 PM

I used a belt sander to level out the cupping warpage of my front porch. Perfect for that application but even the finest grit belt I could find, 220, is too aggressive for a fine furniture usage and would leave edge marks all over the place.

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#2

Re: Beryllium Copper Sander Shoe

04/11/2010 11:07 AM

If I understand correctly, you are considering having a BeCu sheetmetal shoe bent that would slip over the existing head. Might help, I don't know.

Do you have multiple objects to sand? How big? If the piece is larger than the sanding shoe, the belt sander, or a disk sander sounds better to me.

If the piece is smaller than a sheet of sand paper, consider taping the sandpaper to a surface plate and move the object over the stationary sand paper. By applying consistent pressure and turning the object periodically you can get it flat.

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#3

Re: Beryllium Copper Sander Shoe

04/11/2010 11:33 AM

A common sander is a very poor choice of tools to try and use for precision surface work. Between the uneven pressures and sandpaper grain variations that quickly develop from wear plus the possible thermal expansion that occurs rom friction heating the surfaces unevenly I doubt you are gaining anything unless the surface is badly pitted or rough to start with.

Precision surface prep work is done with milling machines are dedicated decking or surface grinding machines with high precision tools.

What are you trying to smooth out and to what degree of 'flat' are you going for and for what purpose?

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#4
In reply to #3

Re: Beryllium Copper Sander Shoe

04/11/2010 12:28 PM

I'm thinking about refinishing some black lacquer furniture and want a flat surface on the sander so that when sanded and finished, it will appear very flat with no waviness. Since the sander has a felt base, I don't want to risk its "deformation" as it passes over undulations. I want a system that acts sort of like block sanding a car but with a bit less effort. In effect, it would be the opposite lapping on a flat surface. Just relying on applying a heavy coat of lacquer and letting it flow out would give a high gloss finish but if the base surface isn't flat, any distortion would show in the reflection plus a thick coating, more than 6-8 mils, will probably crack and craze with temperature changes. I intend to wet sand with very fine paper, 1200 or 1500, and then buff but if there is waviness it will still show. A 3' X 3' piece of sand paper and accompanying machined marble slab 1" thick would be overkill for a small home project.

But the particular point of my question, though, is how well would the tight bends of the beryllium copper hold up to the constant vibration. Would I expect cracking after short usage or is there a better material to use that would withstand the vibration. Just off the top of my head, I would think that sheet stainless would be too soft, and I have seen stainless crack in the past. Titanium or high nickle materials used in jet engines would be perfect but are ridiculous to even consider for this purpose. I need to hear from someone who has worked with beryllium copper in stressful applications. Any connector designers out there?

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#6

Re: Beryllium Copper Sander Shoe

04/11/2010 12:58 PM
  • BerylliumBeryllium-copper (BeCu) alloys usually contain about 2 percent beryllium, but vary ... Beryllium's brittleness is the down side of its advantageous stiffness. Brittleness also ...
    www.globalsecurity.org/wmd/intro/beryllium.htm

If you move the sander over the workpiece at a high rate of speed, you will eventually remove the high spots. Take your time and keepthe sander moving.

Not much I know, but that's about all I know.

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#12
In reply to #6

Re: Beryllium Copper Sander Shoe

04/11/2010 4:06 PM

Thanks for the link to that site. Having worked in the aircraft and other industries that use mil spec cable connectors, I'm aware of its brittleness. The connector shell can withstand a lot of stress but the strain reliefs can fracture if driven over by a fork lift. Go figure. But these are cast items of reasonably pure beryllium. Further in the article it states:

...Beryllium contributes hardness, strength, high electrical and thermal conductivity, and resistance to corrosion, wear, and fatigue. For example, BeCu springs "bounce back" to their original shape again and again.

Be alloys are used for:

  • Springs, switches, relays, and connectors in automobiles, computers, radar and telecommunications equipment, and other instruments ...

With that bit of information and if I can get any testimonials of heavy duty industrial applications that have benefited from it, I'm willing to throw a few bucks at it for laughs. One of our local TV stations highlights various industries around the state and one of them etches, forms and heat treats BeCu for thousands of uses. From the looks of the manufacturing procedure, it shouldn't cost too much to cut a strip, bend it and cook it.

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#7

Re: Beryllium Copper Sander Shoe

04/11/2010 1:59 PM

I want to advise that Be (beryllium) is a toxic and carcinogenic material.

While in a alloy with copper consider wear and tear dust as very dangerous.

It is your decision.

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#8

Re: Beryllium Copper Sander Shoe

04/11/2010 2:18 PM

More to the point when handling BeCu sheet metal items is the risk of cuts from the shoe. Sharp edges are inevitable as the abrasives wear down the edges of the shoe.

I'd wear gloves and a mask.

Is this starting to sound like something you might not want to do?

I would not do it. Let's find another way.

Maybe a hand sanding block? Something long enough to bridge (and only sand) the high spots and leave the low spots untouched.

Good luck.

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#13
In reply to #8

Re: Beryllium Copper Sander Shoe

04/11/2010 4:35 PM

You're right about cuts. Most of the BeCu parts I've handled seem to be sharper than most of my knives at home. MANY cuts and often under a finger nail.

Gloves, masks and eye protection should be worn during any work, even at home changing a tire. Of course I usually ignore all three unless there is a chance of a blister.

References are being made to its toxicity. There is a sizable difference between grinding down an almost pure Be connector shell or other casting and the vibrational "scrubbing" from the non abrasive side of sand paper when used as a backing plate, especially when the material contains only about 2% Be bound to the copper. Just like arsenic. It's all around us, even in the shrimp cocktail and crab legs, but it's not enough to produce a health risk. Saccharin will kill you...if you drink 600 cans of soda every day.

A 2' 2X4 with a strip of emery paper off of a roll is one of my options.

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#15
In reply to #13

Re: Beryllium Copper Sander Shoe

04/11/2010 4:53 PM

Any Idea why it is still called BeCu?

and not hard copper or something else?

Maybe a link to the materials used, like Phosphor Bronze points to Phosphor.

Alloys can be separated in components using different processes.

It is your (ignorant) decision.

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#9

Re: Beryllium Copper Sander Shoe

04/11/2010 2:21 PM

READ THIS

beryllium a corrosion-resistant toxic silvery-white metallic element that occurs chiefly in beryl and is used mainly in X-ray windows and in the manufacture of alloys. Symbol: Be; atomic no.: 4; atomic wt.: 9.012; valency: 2; relative density: 1.848; melting pt.: 1289°C; boiling pt.: 2472°C Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005 Toxicity Beryllium ore The toxicity of beryllium depends upon the duration, intensity and frequency of exposure (features of dose), as well as the form of beryllium and the route of exposure (i.e. inhalation, dermal, ingestion). According to the International Agency for Research on Cancer (IARC), beryllium and beryllium compounds are Category 1 carcinogens; they are carcinogenic to both animals and humans.[40] Chronic berylliosis is a pulmonary and systemic granulomatous disease caused by exposure to beryllium. Acute beryllium disease in the form of chemical pneumonitis was first reported in Europe in 1933 and in the United States in 1943. Cases of chronic berylliosis were first described in 1946 among workers in plants manufacturing fluorescent lamps inMassachusetts. Chronic berylliosis resembles sarcoidosis in many respects, and the differential diagnosis is often difficult. It occasionally killed early workers in nuclear weapons design, such as Herbert Anderson.[41] Although the use of beryllium compounds in fluorescent lighting tubes was discontinued in 1949, potential for exposure to beryllium exists in the nuclear and aerospace industries and in the refining of beryllium metal and melting of beryllium-containing alloys, the manufacturing of electronic devices, and the handling of other beryllium-containing material. Early researchers tasted beryllium and its various compounds for sweetness in order to verify its presence. Modern diagnostic equipment no longer necessitates this highly risky procedure and no attempt should be made to ingest this highly toxic substance. Beryllium and its compounds should be handled with great care and special precautions must be taken when carrying out any activity which could result in the release of beryllium dust (lung cancer is a possible result of prolonged exposure to beryllium laden dust). This substance can be handled safely if certain procedures are followed. No attempt should be made to work with beryllium before familiarization with correct handling procedures. A successful test for beryllium in air and on surfaces has been recently developed and published as an international voluntary consensus standard (ASTM D7202; www.astm.org). The procedure uses dilute ammonium bifluoride for dissolution and fluorescence detection with beryllium bound to sulfonated hydroxybenzoquinoline, allowing detection up to 100 times lower than the recommended limit for beryllium concentration in the workplace. Fluorescence increases with increasing beryllium concentration. The new procedure has been successfully tested on a variety of surfaces and is effective for the dissolution and ultratrace detection of refractory beryllium oxide and siliceous beryllium (ASTM D7458).[42] [edit]Inhalation Beryllium is harmful if inhaled and the effects depend on the duration, intensity, and frequency of exposure. If beryllium concentrations in air are high enough (greater than100 µg/m3), an acute condition can result, called acute beryllium disease, which resembles pneumonia. Occupational and community air standards are effective in preventing most acute lung damage. Long-term beryllium exposure can increase the risk of developing lung cancer. The more common serious health problem from beryllium today is chronic beryllium disease (CBD), discussed below. It continues to occur in industries as diverse as metal recycling, dental laboratories, alloy manufacturing, nuclear weapons production and metal machine shops that work with alloys containing small amounts of beryllium. A 2008 report from the United States National Research Council said that worker exposure to beryllium should be kept "at the lowest feasible level," as the agency's research could not establish any safe level of exposure.[43] [edit]Acute beryllium disease Overexposure to beryllium can cause inflammation of the upper and/or lower respiratory tracts. The symptoms of acute beryllium disease are non-specific, resembling other inhalational injuries, viral infections, or pneumonia[44]. Upper respiratory findings include nasopharyngitis and tracheobronchitis. Symptoms may include irritation of thenares and pharynx, epistaxis, cough, and a metallic taste. Nasopharyngitis can progress to formation of nasal fissures, ulcerations, or perforation. Therapy is supportive and includes removal from further beryllium exposure. Acute beryllium pneumonitis produces severe cough (occasionally with blood-streaked sputum), chest pain or burning, and shortness of breath[44]. The patient is usually ill-appearing, and present with hypoxemia, cyanosis, tachycardia, and shallow rapid breathing. Systemic symptoms include fever (usually low-grade), malaise, and anorexia. The chest X-ray can reveal diffuse, bilateral alveolar infiltrates. There is no specific diagnostic test for acute beryllium disease. Biopsy of the lungs reveals a nonspecific granulomatous inflammation. Treatment is supportive, including oxygen supplementation as needed, and removal from further beryllium exposure. Corticosteroids are sometimes tried, but there are no good controlled studies reported. The signs and symptoms of acute beryllium pneumonitis usually resolve over several weeks to months, but it may be fatal, and about 15-20% of cases may progress to CBD[45]. [edit]Chronic beryllium disease (CBD) The average rate of sensitization to beryllium ranges from 1-5%, depending upon exposure details[46][47]. Sensitization is not an illness, but some of these individuals, if inhaling sufficient quantities of beryllium dust in the micrometer-size range, may have an inflammatory reaction that principally targets the respiratory system and skin. This condition is called chronic beryllium disease (CBD), and can occur within a few months or many years (average 10 years in some series[48]) after exposure to higher-than-normal levels of beryllium (greater than 0.2 µg/m3). This disease causes fatigue, weakness, night sweats and can cause difficulty in breathing and a persistent dry cough. It can result in anorexia, weight loss, and may also lead to right-side heart enlargement and heart disease in advanced cases. Typically, CBD has an insidious onset and runs an indolent course. Some people who are sensitized to beryllium may not have symptoms, and just being sensitized is not a recognized health effect. CBD occurs when the body's immune system recognizes beryllium particles as foreign material and mounts an immune system attack against the particles. Because these particles are typically inhaled into the lungs, the lungs become the major site where the immune system responds. The lung sacs become inflamed and fill with large numbers ofwhite blood cells that accumulate wherever beryllium particles are found. These cells form balls around the beryllium particles called "granulomas." When enough of these develop, they interfere with the normal function of the organ. Over time, the lungs become stiff and lose their ability to help transfer oxygen from the air into the bloodstream. Early on in the disease, there may be a mild obstructive ventilatory defect. In advanced cases, there is a restrictive defect and reduced diffusion capacity. Patients with CBD develop difficulty inhaling and exhaling sufficient amounts of air, and the amount of oxygen in their bloodstreams falls. Most of the clinical features of CBD are indistinguishable from thoracic involvement with sarcoidosis. The chest radiograph usually reveals bilateral, mid- and upper-lobe predominant reticulonodular infiltrates, as well as hilar and mediastinal adenopathy. For suspected cases of CBD, fiber-optic bronchoscopy with bronchoalveolar lavage (BAL) is indicated. The BAL fluid should undergo beryllium lymphocyte proliferation testing (BAL BeLPT), the "gold standard" for the diagnosis. The measurement of beryllium in urine or tissue does not establish the diagnosis, and there are technical and interpretive problems with these tests. Blood BeLPT detects approximately 70-90% of CBD cases. CBD is treatable, but not curable with traditional drugs and medicine. Removal from further beryllium exposure is advisable. Treatment includes supplemental oxygen and corticosteroids (such asprednisone) to lower the body's overreaction to beryllium. If therapy with corticosteroid is successful, treatment is usually continued lifelong because of disease relapse after steroid cessation[44]. In general, CBD worsens without treatment. Prognosis is best for those diagnosed at an earlier stage. Overall mortality rates are 5-38%[49]. The general population is unlikely to develop acute or chronic beryllium disease because ambient air levels of beryllium are normally very low (<0.03 ng/m3).[50] [edit]Ingestion Swallowing beryllium has not been reported to cause effects in humans because very little beryllium is absorbed from the stomach and intestines. Harmful effects have sometimes been seen in animals ingesting beryllium.[51] [edit]Dermatological effects Beryllium can cause local irritation and contact dermatitis. Beryllium contact with skin that has been scraped or cut may cause rashes, ulcers, or bumps under the skin called granulomas.[52] Beryllium dust or powder can irritate the eyes, producing itching, burning, or conjunctivitis. [edit]Effects on children There are no studies on the health effects of children exposed to beryllium, although individual cases of CBD have been reported in children of beryllium workers from the 1940s. It is unknown whether children differ from adults in their susceptibility to beryllium. It is unclear whether beryllium is teratogenic.[53] [edit]Detection in the body Beryllium can be measured in the urine and blood. The amount of beryllium in blood or urine may not indicate time or quantity of exposure. Beryllium levels can also be measured in lung and skin samples. While such measurements may help establish that exposure has occurred, other tests are used to determine if that exposure has resulted in health effects. A blood test, the blood beryllium lymphocyte proliferation test (BeLPT), identifies beryllium sensitization and has predictive value for CBD. The BeLPT has become the standard test for detecting beryllium sensitization and CBD in individuals who are suspected of having CBD and to help distinguish it from similar conditions such as sarcoidosis. It is also the main test used in industry health programs to monitor whether disease is occurring among current and former workers who have been exposed to beryllium on the job. The test can detect disease that is at an early stage, or can detect disease at more advanced stages of illness as well. The BeLPT can also be performed using cells obtained from a person's lung by a procedure called "bronchoscopy".[54] [edit]Industrial release and occupational exposure limits Typical levels of beryllium that industries may release into the air are of the order of 0.01 µg/m3, averaged over a 30-day period, or 2 µg/m3 of workroom air for an 8-hour work shift. Compliance with the current U.S. Occupational Safety and Health Administration (OSHA) permissible exposure limit for beryllium of 2 µg/m3 has been determined to be inadequate to protect workers from developing beryllium sensitization and CBD. The American Conference of Governmental Industrial Hygienists (ACGIH), which is an independent organization of experts in the field of occupational health, has proposed a threshold limit value (TLV) of 0.05 µg/m3 in a 2006 Notice of Intended Change (NIC). This TLV is 40 times lower than the current OSHA permissible exposure limit, reflecting the ACGIH analysis of best available peer-reviewed research data concerning how little airborne beryllium is required to cause sensitization and CBD. Because it can be difficult to control industrial exposures to beryllium, it is advisable to use any methods possible to reduce airborne and surface contamination by beryllium, to minimize the use of beryllium and beryllium-containing alloys whenever possible, and to educate people about the potential hazards if they are likely to encounter beryllium dust or fumes.[55] On 29 January 2009, the Los Alamos National Laboratory announced it was notifying nearly 2,000 current and former employees and visitors that they may have been exposed to beryllium in the lab and may be at risk of disease. Concern over possible exposure to the material was first raised in November 2008, when a box containing beryllium was received at the laboratory's short-term storage facility.[56] [edit]From Wiki:

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#10
In reply to #9

Re: Beryllium Copper Sander Shoe

04/11/2010 2:29 PM

We are in agreement that this is not a good idea, but the BeCu we are discussing here is usually only 2% Be. This form of Be Cu is still toxic.

I believe that your reference applies to pure Be. Good reference, none the less. Scares me and I'm fearless.

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#11
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Re: Beryllium Copper Sander Shoe

04/11/2010 3:13 PM

2% means also, ONLY 50 times less exposure to reach LD. (lethal dose)

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#14
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Re: Beryllium Copper Sander Shoe

04/11/2010 4:50 PM

When I was applying for a position in a wafer foundry, I looked up arsenic. Nearly put me off shellfish. Exploding corpuscles got my attention. Almost makes me feel guilty for putting people at risk every time I turn on an electronic device...almost. I've gotten to feel the same way when I go to an all-you-can-eat crab leg buffet. But I do loves dem crabs, man.

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#34
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Re: Beryllium Copper Sander Shoe

04/12/2010 2:16 AM

Back in the early 70s I prepared a report on the machining of Beryllium and Be containing alloys to the dept of space as they were interested in machining components for inertial navigation.

One of the major problems in those days was the incidence of pig's knuckle disease among workers machining beryllium alloys. The procedures to avoid this were so demanding that the project was abandoned.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1802448/pdf/annsurg01413-0126.pdf

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#17
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Re: Beryllium Copper Sander Shoe

04/11/2010 5:22 PM

Also from Wiki:

As beryllium compounds are toxic there are some safety concerns for handling its alloys. In solid form and as finished parts, beryllium copper presents no particular health hazard. However, breathing its dust, as formed when machining or welding may cause serious lung damage.[2] Beryllium compounds are known human carcinogens when inhaled.[3] As a result, beryllium copper is sometimes replaced by safer copper alloys such as Cu-Ni-Sn bronze.[4]

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#16

Re: Beryllium Copper Sander Shoe

04/11/2010 5:20 PM

How about going back to square one - how was surface flatness and finish originally obtained?

As you're talking about furniture, I would suspect traditional tools, such as a cabinet scraper, possibly followed by some very fine sandpaper, then many layers of lacquer with fine wet-and-dry between.

(I may be talking through the wrong orifice, but someone got flat lacquered finishes on furniture by hand once upon a time).

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#20
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Re: Beryllium Copper Sander Shoe

04/11/2010 6:42 PM

I'm familiar with the cabinet scraper/French polish method with lacquer beetle carcases in an alcohol dampened pounce bag, and a fair number of techniques in between, but this furniture is a far cry from Louis IV. I just want to git-er-done. These pieces were factory made where I'm sure reasonable expense was invested in large belt sanding machines that inherently produce flat surfaces on large pieces by design.

In Wiki, substituting bronze (Cu Ni Sn) was suggested as a less hazardous material. Since I don't need the springy characteristics, except for resilience and cracking resistance, how do you see that? The nice thing about Be Cu is that it can be easily formed THEN heat treated to resist "un forming". I'm not sure if bronze works the same way and may be difficult to form into tight 90o angles and resist cracking. I really want to involve the electric sander in this. My back and shoulder aren't what they used to be.

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#18

Re: Beryllium Copper Sander Shoe

04/11/2010 6:03 PM

CAPS INTENTIONAL. YES I'M SHOUTING.

DO NOT USE BeCu IN THIS APPLICATION!!!! YOU WILL PROBABLY KILL SOMEONE AS A RESULT OF YOUR ACTIONS. IF NOT YOU, THEN A LOVED ONE. A SLOW AND PAINFUL AND HORRIBLE WAY TO GO.

The necessary precautions to use Be products alone, but to considder using it in an abbrasive, dust producing situation is abhorrent. Handling the stuf is OK provided you don't get any cuts, but suggesting to KNOWINGLY use it in this way is horrible. Find some other material or get another shoe for your sander.

If you want specific details of my involvement with BeCu, then send me a pm.

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#19
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Re: Beryllium Copper Sander Shoe

04/11/2010 6:17 PM

The material is not intended to be used as an abrasive but as a flat interface between the felt pad and backside of the sand paper.

I've tried putting a piece of veneer between the sand paper and the sander base but soon after turning it on, the veneer either destroys the sand paper where it bends around at the crimping bar or if I cut it shorter, it vibrates out from under the sand paper.

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#21

Re: Beryllium Copper Sander Shoe

04/11/2010 7:19 PM

There's no need for anything so exotic. I'd just try a piece of stainless steel, probably 14ga, maybe a little thicker if there's room.

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#22

Re: Beryllium Copper Sander Shoe

04/11/2010 8:08 PM

I wonder why you think bent sheet metal will be flat and stable enough for your purpose.

A plate of thick enough steel could be ground very flat using the rotating platen method suggested by lyn"thingy"lynch like all us metallurgists do to create perfectly flat surfaces on our samples, (And when using diamond slurry to buff the scratches out of our watch crystals {:-)

milo (apologies LYNLYNCH)

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#23
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Re: Beryllium Copper Sander Shoe

04/11/2010 9:49 PM

The bend style is to accommodate the on-board clamp of the sander. The material of the shoe has to be thin enough to fit under the clamp bar along with the sand paper. I haven't measured the max thickness that can fit under the clamp but just eyeballing it, the BeCu (which I will abandon in favor of bronze or phosphor bronze barring any objection) I know would be thin and tough enough to work. 14ga stainless might be too thick. 20ga and 22ga sound close enough. I'll have to determine the limits. Sure wish I had a table-top bender/roll former/shear. Harbor Freight here I come. I needed a reason to buy another tool anyway.

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#24
In reply to #23

Re: Beryllium Copper Sander Shoe

04/11/2010 10:08 PM

A motion to buy new tools is ALWAYS in order. milo

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#26
In reply to #23

Re: Beryllium Copper Sander Shoe

04/11/2010 10:33 PM

My sanders have all a aluminum plate with rubber glued on it.

Sometimes I leave the old sand paper and just clamp another one on top of it.

Same with rotating devices that have only a rubber backing disk.

The smoothness and uniformity result is a operator factor. Pressure applied, time spent, moving speed and sliding direction(s) of the machine, or in one word: skill.

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#31
In reply to #23

Re: Beryllium Copper Sander Shoe

04/12/2010 12:08 AM

this will do OK as is

http://www.grainger.com/Grainger/items/6Z565?Pid=search

You can add a more rigid base after removing the foam, I used to use one with a phenolic base to resurface 30"x40" aluminum plates.

if you can find it on a 2" roll [sanding cloth] you can use it

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#39
In reply to #31

Re: Beryllium Copper Sander Shoe

04/12/2010 9:47 AM

That's the idea I'm trying to apply to my sander but I hadn't considered removing the felt pad. The pad on mine is bonded to the hard plate and removing it would ruin it for future use. Those body sanders are kinda pricey for this small project.

Thanks everyone for your input. Information I've gotten here will serve me for this project as well as future projects.

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#40
In reply to #23

Re: Beryllium Copper Sander Shoe

04/12/2010 3:24 PM

I worked with BeCu in a foundry for over 25 years. Went to symposiums and meetings by Brush Wellman and other suppliers. Made hundreds if not thousands of molds for plastic injection molds and blow molds. There is a lot of misinformation out there. Like the old saying goes, "a little bit of knowledge can be dangerous."

For most BeCu uses there is no health hazard. For Be disease 3 conditions MUST be prevalent:

1 Person MUST be sensitive to Be exposure. Some people smoke for 50 years and never get lung cancer. Some people get it from 2nd hand smoke.

2 Be MUST be AIRBORNE and RESPIRABLE, i.e. fumes of pure Be, grinding particles from pure Be. The Be is in a copper solution like 20c (2% Be- 98% Cu). Dry grinding requires environmental controls and collection if you are dry grinding that material. You are placing it behind the sandpaper. Can anyone explain to me how the human body separates the Be from the Cu when it inhales the BeCu dust? I personally would not recommend inhaling ANY metallic dust, BeCu, aluminum, copper, cast iron etc. As you are probably well aware of, there are many woods when inhaled can be toxic. The fumes from cashew nut oil can do a job on you but I've eaten a whole can of cashews and survived.

and 3 The airborne concentration must be SIGNIFICANT.

I had a customer call up that one of his men said that he got sick from machining a BeCu casting that we had made for him and wanted to go home with pay. I asked what he was doing to it. Turning it down on a lathe he said. Was he eating the curls or the chips? No, he was just standing nearby operating the lathe. Sucks to be him because there was no way the BeCu could have done it unless he was eating it. Berylliosis like asbestosis takes like years to show up, not in an afternoon exposed to lathe turnings. I think he fired the clown. Sounded like a finagler.

I personally think from what you describe that a piece of plain copper such as used in bus bars would suffice. You want to use an annealed form so you can easily bend it and anything over 1/16" would be difficult to make a tight radius. You could probably get something like double stick tape or that stuff that Black & Decker and the rest use to stick the sanding pads on the rubber backers and glue that to the backside of the copper to hold it in place. I have used 1/4" copper bus and I would not want to try and bend it to any tight radius.

BeCu is a lot more expensive and you would want to get it in the "A" temper. When it hardens it gets stronger and more brittle. The elongation drops rapidly as the hardness goes up. Copper is much more available. I think McMaster Carr probably still carries it.

Hope this helped.

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#44
In reply to #23

Re: Beryllium Copper Sander Shoe

04/15/2010 11:14 AM

"I needed a reason to buy another tool anyway."

Try a half sheet sander instead of the 1/4 sheet palm sander. They are harder to find but using one in a crisscross manner produces a fine flat finish.

OR; get another palm sander and glue a slightly smaller piece of ( metal of choice ) to the bottom with a high temp. epoxy.

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#46
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Re: Beryllium Copper Sander Shoe

04/16/2010 1:05 AM

I was at a trade show yesterday where I spoke to a metal stamping company rep. He is going to bend up a piece of 17-4 ph stainless from scrap he has around, half the price of BeCu, and heat treat it.

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#47
In reply to #46

Re: Beryllium Copper Sander Shoe

04/16/2010 8:41 AM

With a hard backing plate you will find it works better to use 2 or more sheets of sandpaper at a time.

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#48
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Re: Beryllium Copper Sander Shoe

04/16/2010 11:33 AM

Good point. Thanks

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#49
In reply to #46

Re: Beryllium Copper Sander Shoe

04/16/2010 11:35 AM

'Tis good to have friends in low places....=b

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#25

Re: Beryllium Copper Sander Shoe

04/11/2010 10:13 PM

This all sounds like an overly complicated way of doing something that is basic and simple in another application.

Have a look around at the local auto body supply stores for what they have. Most modern auto body sanders have sticky pad sand paper and the sanders themselves have many types of bases including perfectly flat metal ones. Also auto body sandpaper comes in grits to over 3000.

If you cant get it flat enough or smooth enough with that equipment you probably need OCD meds!

Sometimes you just have to look at another application where obsessive detail is common practice to find the right equipment.

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#38
In reply to #25

Re: Beryllium Copper Sander Shoe

04/12/2010 9:18 AM

I thought about one of those 18" long 2" wide power sanders but they are in the $100 range. I figured a piece of bent metal would be cheaper for this short term project. I'll have to check if they have stick-on sheets for that sander that go to at least 400 grit that I can stick to an 18" piece of 1" x 2". Once the surface is flat at 400, finer papers stuck to a piece of 2" x 10" with spray trim adhesive would do it.

Thanks for rattling my brain enough to get most of the balls in the right holes. Cancel the trip to Harbor Freight and get out the circular saw. I'm gonna slice up some scrap wood.

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#27

Re: Beryllium Copper Sander Shoe

04/11/2010 10:44 PM

RE: Sanding belt grits. Try"Brownells" they carry belts to 400 grit in various sizes. I STRONGLYsuggest you stay away from BeCu alloys for your backing plate. I've never seen a backing plate that didn't show wear. It doesn't take much fine dust to ruin your day (after day after day) bluebelly73

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#28

Re: Beryllium Copper Sander Shoe

04/11/2010 11:37 PM

Fine furniture was finished long before electricity was, "invented".

Sand it by hand and appreciate the imperfections.

I'm all for patina!

I'm sure Milo is too.

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#32
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Re: Beryllium Copper Sander Shoe

04/12/2010 12:27 AM

Well said

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#33
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Re: Beryllium Copper Sander Shoe

04/12/2010 12:32 AM

Thanks. Welcome to the group. Hang around.

LL

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#29

Re: Beryllium Copper Sander Shoe

04/11/2010 11:40 PM

I don't want to oversimplify your project but- Have you tried a random orbit sander for this project? When used properly, this is the type of project that it is designed for. They are used extensively in the autobody industry for the same type of sanding you are indicating that you want to do on wood. A variable speed top of the line unit with velcro attached sanding disks is less than $90 at the big box stores.

It would certainly be easier, simplier and healthier than what you are considering.

Use a long straight edge to check for flatness.

If you want extremely fine disks try a auto paint supplier.

I am the owner of a 50yr old family made 20ft wooden sailboat and I always use an orgital sander for finish sanding prior to using urethane paint and varnish. Some of it is so smooth that some people think that it is gel-coat.

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#36
In reply to #29

Re: Beryllium Copper Sander Shoe

04/12/2010 5:09 AM

GA from me!

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#41
In reply to #29

Re: Beryllium Copper Sander Shoe

04/12/2010 5:46 PM

Old Salt, Andy Germany & Jaguar,

The orbital sander is the way to go; I will not pretend to be a good craftsman but I once over achieved on a surface, I obtained a finish that I was really, really proud of until a tradesman came around to do another job and wrecked the first one - split the wood right down the middle. He was not supposed to touch that surface!

But I shall always remeber that finish - achieved by many careful hours with the orbital sander going up grades to, memory here, 800 grit. Time, care and process. I know that I could do that again if I found the hours!

It was a flat surface so in that respect it was easy but it was so much better than any other surface in the place.......

Good Luck with what you are trying to achieve

Sleepy

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#30

Re: Beryllium Copper Sander Shoe

04/12/2010 12:03 AM

How about using a large woodworking plane e.g. Stanley or Record #8 with abrasive paper attached. It will give you handles and a flat surface to work with. And yes, why go for something like BeCu when there's so much more readily available with no hazards associated.

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#35

Re: Beryllium Copper Sander Shoe

04/12/2010 4:39 AM

Hi,

in the environment of machine tools there is an allowed beryllium concentration of 2 micrograms per cubic meter (same as for nickel)!

From a standpoint of regularly working in such an atmosphere I think this is much too high - but difficult too lower without separately venting the machine and its workspace.

In the wet waste 20mg per liter are allowed. (Assumed not to be inhaled).

One problem is the toxicity of beryllium: it is taking place in our body's enzyme systems - nearly any of the metallic atoms that are needed for proper function of our body chemistry can be replaced and is then nonfunctional.

As a consequence the symptoms of Be poisoning are not clearly visible to ordinary medical persons!

The second problem are the allergies (as with nickel). These can be triggered by so minute amounts of material that there are allergies to Be by unknown sources - may be emerald- and aquamarine-jewelry. Or simply dust from soils that often contain some micrograms Be per Kg.

So: no need to use anything containing Be. If you want a "shoe" then any plastic will do it, else any brass.

Have in mind that this old furniture was made by hand without any machines!

RHABE

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#37

Re: Beryllium Copper Sander Shoe

04/12/2010 5:18 AM

It must be possible to have a steel shoe ground by an engineering company to a good flat surface, no need to risk the health of yourself or others using poisonous metals.....

What Old Salt wrote should help, with a strong light behind it to see the crack (or not!).

Thats what we used in my RN training when I was learning to file different metals by hand into complex shapes with an accuracy on all dimensions of 1/1000" or better.....that must be good enough for wood or whatever you are sanding......

That was my all time favourite course in the RN, sevberal times a week, for 3 hours at a time, working with metal.....brilliant training.....

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#42

Re: Beryllium Copper Sander Shoe

04/14/2010 6:01 PM

DO NOT use BeCu for this unless you like the idea of dying. 1 in 3 people exposed to BeCu dust die of beryllosis. that is not good odds.

Do yourself and everyone who may ever work in the space you are working in a favor and just take it to somebody and pay have the dang thing blanchard ground and be done with it. it'll be cheaper in the long run anyway.

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#43
In reply to #42

Re: Beryllium Copper Sander Shoe

04/15/2010 11:10 AM

Please cite source for this statistic so I may do some research.

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#45
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Re: Beryllium Copper Sander Shoe

04/15/2010 2:55 PM

I'm pretty sure it was RHABE that first mentioned that statistic on CR4 before, but I could be wrong on that too.

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