US1721949A - Plating and polishing electrode - Google Patents

Description

252. CQMPOSITIONS.

'July 23, 1929.

Cross P. E. EDELMAN 1,721,949

PLATING AND POLISHING ELECTRODE mea nay 7. Y192e EAD ALUM/NUM 7%]/35/3 'f'wer or/c Acli INVEN TOR.

Examiner Patented July 23, 1929.

UNITED STATES PHILIP E. EDELHAN, F CHICAGO, ILLINOIS.

PLATING A ND POLISHING ELECTRODE.

Application led Hay Z,

Mypresent invention relates to p ad anodes .of the class described in my copending application for U. S. Letters Patent, Serial No.

272,041, filed April 23, 1928, and has for its objects (1) to include the operating chemicals in the pad itself, (2) to permitv dry shipment of the pad in form' operativeon dipping into water, (3) .to include polishing ingredients in the pad in manner operative by exudation to form a mild abrasive surface for polishing, (4) to proportion the ingredients whereby the re-coating effect is greater tbaii the abrasive or polishinv effect of the electric pad, and (5) to afford interchange or renewal of operative chemical ingredients.

My electric pad affords in iract ce a port- "ble practical elec ro-p a ing andpolisliiiwL1 deviceinwhich the ingredients' are proportioiied for cleaning, replatiiig, and Iiiilishinr ainetvalobject without removing saldi-)biedt ""Wfroiii the supporting member to which it is attached. The operations of replating the metal object and polishing same are simultaneous. with replating preponderant, so that a bright lustrous new metal coat results. This differs from mere gilding or coating by contact of solutions, pastes, or metal and solution contacts.

Thus where only a thin temporary coatunable to support polishing is had by gilding, solution, or solution and metal contact, my electric ad affords a homogenous hard coating simultaneously polished and able to .withstand additional polishing. Also objects can be successfully coated when some what dirty because the abrasive action of the pad affords the necessary cleaning. Worn objects can be neatly patched and recoated by this means.

My invent'on is suitable for any metal coating, as for example, nickel, cpbalt, chromium, copper, silver, gold, platinum, antimony, bismuth or any suitable metallic alloys which can be electroplated. When automobile parts are to be re-finislied, the car battery can be. used as a source of current it the battery is grounded at its negative terminal. Or if desired, a separate battery may be used or a rectifier or power unit supply source such as described inmy co-pending application for U. S. Letters Patent of the United States Serial No. 192,069, tiled Ma 17, 1927, maybe employed. The voltage an current require- 1928. Serial No. 275,650.

, ments will vary according to the metal to be density than is customary for liquid baths. 6o

My invention differs from bath dips etc. in that the electric pad is most effective when just moist and not dripping wet. There is sufiicient resistance in the electrolyte formedV in the pad to regulate the current flow and a certain heating action is caused by the electric current dow and rubbing action of the pad which is beneficial for rapid thick de osit results.-

have discovered also that the anode metal need not be the same as the metal to be plated, as in general any metal lower in the electromotive series and substantially insoluble in the electrolyte formed` in the pad is suitable. Thus for nlckel plating, lead sheet affords a suitable anode material, while either lead or iron is suitable for chromium plating anode material. Also, since aluminum is protected by a film formed on its surface and inasmuch as aluminum readily combines with free oxygen liberated by electrolysis, it is an advantage to use a laminated anode of sheet aluminum riveted to lead or steel by eyelet rivets. Reliance is had on the renewal of the electrolyte salts for maintaining the pad g5 operative. A

Thus I prefer to use metallic salts and assisting chemicals therefor in the pad in proportion with certain readily soluble ingredients and other less soluble ingredients, as

exemplified in the case of nickel plating by use of powdered nickel salts consisting of a mixture in dry form of both nickel-ammonium sulphate (double salt, diicult to dissolve), and nickel sulphate (single salt, readily soluble), preferably. with the first named double salt in excess in the vicinit ,of y the anode. Then when the anode pa is soaked in water a few minutes the single salt first dissolves, while the double salt serves as a re-inforcing agent to maintain the electrolyte at propel-- plating strength. 1

The chemicals used depend on the metal to be plated and ingeneral' are used in more i concentrated roportion in my electric pad' 105 y Y than for wet atlis in tanks.' I indicate by way of example suitable c hemicals butvvarious changes and modilcations may be made 52. COMPOSITIONS.

Cross bv anyone skilled in the art within the spirit of the idea disclosed and within the scope of the appended claims.

An exemplification of the invention is had for nickel plating. The combination requires the following parts.

Reference is made to the accompanylng drawing in which the figure is a diagram, partially sectioned, showing the relation of the parts.

A connector (A) is joined to electrode (B) formed of an aluminum and a lead sheet respectively. A wrapping pad (C) made from fabric bags surrounds electrode (B). Slowly soluble crystals reduced to powder are included by inner wrapping (C) in the vicinity of electrode (B). Soluble electrolytle chemicals are placed between the wrapping bags (C). Chemicals placed between the wrappings (C) are indicated by letter (D). The chemical (D) largely is comprised by polishing powder and boric acid adjacent to the outer wrapping bag (C). A pad containing operating chemicals is thereby provided, as bags (C) are permeable to chemicals (D) which form an electrolyte about anode (B) when pad (C) is immersed or wetted with Water.

The combination of the figure comprises, as set forth, an electric pad, or portable plating and polishing appliance.

(A.) Means to "onnect the anode and work to a source of electric current.

(B.) A metallic anode (which for electrocleaning purposes may also be made a temporar cathode, when desired).

C. A pad, preferably containing absor ent material and a soft fabric covering, enclosing the anode and the operating chemicals.

(D.) Operating chemicals including metallic salts, assisting chemicals, (in substantially dry or non-spilling form), and polishing or mild abrasive powder having the propcrty of exuding thru the outer fabric covering provided by part (C).

Thus for nickel plating and polishing, part (A) may comprise a flexible No. 14 rubber covered wire, having one end thereof soldered to a battery clip attachable to the positive terminal of a storage battery, and its other end soldered or welded to the anode part (B) then protected by rubber or pitch coating so that the copper wire will not bc attacked by part (D). A wire 1l feet long is lsuitable. lVhere the metal object to bc coated is not grounded to the battery used for plating. a similar wire with two clips, one at cach end, may be used to connect said work as a cathode to said battery.

The part (B) may'have an area of 2% by {5l/ inches for nickel platingr and comprise a thin sheet of nickel, or sheet lead, or preferably a laminated pair of sheets, one of which is aluminum and the other lead. lThin sheets Examiner are desirable to make the electric pad flexible so that odd shapes in the work to .be coated may be reached thereby. For chromium plating, the laminated electrode may be made from one sheet of lead riveted to one thin sheet of steel or aluminum. Larger or smaller anode arca may be employed where desired, but the dnncnsions stated will suf- Ytice for passing a plating current varying from 1 to l0 ampcres according to the manner in which the anode is pressed with rcspect to the work to be coated. Tubular rivets are suitable for holding the anode laminations together. 1f tin is included in the alloy to be plated, the anode materials must be lower in the clcctromotive series than tin and insoluble in the electrolyte formed in the pad when same is dipped in water. The anode should be made with rounded corners that will not tear thru the covering mate rial For electgoclcaningbythe pad method thlilelmode can'be ii'sed',"o`i"pre feral ily a duplicate anode, will be'used and connected as a cathode, with the work connected asthe anode. 'l`l1eclectrolyte material may be, for cleaning, a`mixture of water with such gritty ers. It is desirable to have a separate cleaning electrode 1n' order not to contaminate the "The removed coating from the work anode will then precipita-te as a sludge easily washed away. Large objects can bc clcancd at small areas thereof without neccssitatiug removal from attached supports, to permit recoating worn areas thereof.

The pad (C) essentially must encase. thc anode or electrode (B) to prevent direct contactI thereof with the work connected as cathode with respect thereto (or reveisely, in the case of electro-cleaning). Various assemblies for the pad are suitable, an exemplitication being the following combination.

A canvas or cotton bag is tiled around thc part (B). A portion of the chemicals (D) are included in this bag, and in the case of nickel plating, most of the more dillicultly solublel double salts aforesaid will be included in this first bag. The chemicals (D), can be loose in this bag or wrapper but may be tufted 'therewith by lsewing' or pasting tutt portions on the bag, or apiece of cellucotton or outing flannel can be used sandwiched around the anode (B) to hold the chemicals (D) thcrcabout. Any means which will hold the chemical powders (D) with respect to electrode (Il) in the bag is suitable.

A second bag or wrapper is now slipped over the first bag and tied with draw strings, and may cont-ain a further portion of the chemicals (D), but preponderant with the more soluble portions thereof. Similarly a third fabric bag or wrapping may be now lUl) llt)

lill) tinal eucasing bag should preferably be made from soft material such as outing flannel and largely contain the abrasive polishing powder and acid crystal components of the chemicals (D). The latter powders of (D) are readily able to exude or penetrate thru the pores of the last bag of pad (C) to alord effective cleansing and polishing action. Probably the multiple bags of the pad (C) afford a certain electrical diaphragm action and exert a beneficial electrical endosmosis elect. I have observed that by such construction, dirt and deposits accumulating on the outer bag in use, do not penetrate to the inner bag. The outer bag can accordingly be removed and renewed without detriment to the action after prolonged use of pad (C) The variousparts used are well known and understood but a new and useful result is laliorded by the new combination thereof whereby the new result `stated is attained in simple and practical manner. The polishing eii'ect of chemicals in the outer bag is proportioned so that the plating effect simultaneoustherewith is preponderant thereover.

Where desired, the bags and absorbent material (such as cellucotton) aforestated may be sewed or fastened together, but in practice, equally good results are obtained by merely wrapping or encasing one of said coverings forming said pad (C) around the next preceding one.

The operating chemicals (D) will vary according to the work andas an example,

l l l'.

tent of chemicals (D).

suitable ingredients are specified for nickel plating.- In general the operating chemicals (D) will include metallic salts of varying solubilities with the least soluble metallic salts nearest to the anode, also the abrasive or polishing ingredients will be preferably included only in the outer pad wrappingor bag, separately, or with the acid crystal con'- 'Ilhe abrasive or polishing material of (D) must not be capable of reacting unfavorably with the other chemicals used. I have found ordinary infusorial energia/powder (tripoli) suitable. A so the preparation sold as siliceous cleansing powder works well. Whiting appears less suitable, and alkali cleaners cause dark streaks on the work. Pumice powder is rather too abrasive for most work but may be used with the infusorial earth if desired.

As aforesaid, the pad (C) will thus have preferably a series of fabric layers each including certain portions of the chemicals (D), though nearly as goodresults can be had by a single mix of vsaid chemicals when only two bags or coverings (C) for electrode (B) are used.

For nickel platin", suitable dry proportions are, for examp e Chemicals Parts Nickel sulphate, single salts 3 Nickel ammonium sulphate, double salts 8 Magnesium sulphate )i Ammonium chloride 1 2 n usonal earth 2 una lVhen a hard nickel is desired, cobalt sulphate or cobalt-ammonium sulphate may be substituted for the nickel sulphate single salts. Any suitable mild abrasive polish powder can besubstituted for the infusorial earth. The magnesium sulphate and the ammonium chloride content may be minimized or varied as may be desired, but an excess of boric acid or some equivalent acid crys- .tal ingredient is desirable.

The ingredients of the example are reduced to powder and intermixed as a single mixture or preferably with various proportions of the total. Thus in the latter case, 7 parts of the nickel ammonium sulphate, 1/1 part magnesium sulphate, 1/2 part ammonium chloride may be mixed and included in the first wrapping of (C) around anode (B), while the remainder may be mixed separately and included in the outer bag of pad (C). Or if a plurality of bags are used for pad (C) the outer bag may include only portions of the boric acid and all of the. infusorial earth or equivalent specified. lVhen cobalt addition is used as aforestated precautions should be taken against the poisonous property thereof, it being desirable for the operator to wear rubber gloves or employ a wooden stick in manipulation of pad (C). The specified in grcdients are not harmful to the hands of a normal person and if accidentally spilled may be washed away from other parts than the work treated, without harm. The ingredients are more or less soluble, as stated except the infusorial earth, which however is finely divided and able to exude or penetrate thru the outer bag and exert its abrasive or polishing action on the work.

In use, the pad (C) with prepared chemical content (D) is in dry or substantially dry `form. It is rendered operative by brief immersion in asmall jar of hot water. Excess water is rinsed therefrom and the pad (C) with operating chemicals and water content is to be used in moist condition without excess dripping water or electrolyte. After initial use, the pady (C) aforesaid may be further dipped in moistening water as stated.

The work to be refinished should be preferabl first cleaned and dried, though work whic is not too dirty can be retinished directly Without preparation. For cleaning,

52. courusulous. ,f

Cross tis the work should be scoured or electro-cleaned, using an electric pad of the kind set forth connected as a cathode with the work connected as "an anode, employing an alkali scouring agent with water as the cleaning electrolyte. The work when cleaned is washed and preferably dried.

In applying the electric pad, a firm continuous motion is desirable. The pad should not be left in one position on the work, but should be rubbed thereon with continuous motion. This prevents formation of spots. If spots occur by forgetting to rub as stated, they can ordinarily be removed by simply further rubbing the plating pad thercover. After prolonged use the outer bag should be renewed as aforestated.

The` rubbing operation both plates and polishes the work and the result is continuously visible. Sharp corners or depressions on the work which require building up are easily reached and patched with smooth lustrous re-finish. The plating is rapid and requires but a few minutes for a serviceable durable coating. Parts worn brassy or down to copper base are easily renewed in this manner. The present invention differs from my aforesaid copending application for Letters Patent in the improvements stated and especially in that the electric pad maybe shipped dry ready for use, without requiring cans of operating ingredients. Also the combination specified puts the polishing ingredient inside the last wra ping of ad (C) where it is surprisingly e ective by t e stated action. Readings of a series connected ammeter on a 6 volt buttery on average work show a current consumption averaging 5 amperes. The deposit obtained is firm and adhering and does not rub off, nor crack. It will even stand considerable scouring without signs of wearing thru to the base object.

I have now fully set forth an exemplitication of my invention and it will be understood that anymetal or alloy can be plated and polished by use of suitable ingredients in chemicals (D). The various chemicals suitable for most metals and alloys are well known and understood and reference is made to Electro-Deposition of Metals by Langbein-Brannt published 1924 by Henry Carey Baird & Co. New York for principles and formulas applicable to other metals. However in the case of chromium, I will now specify an operable mixture for (D). A

For chromium plating, the work should first be cleaned and dried thoroughly and preferably coated with nickel. This may be done as herein specified or by any suitable method. The nickelled surface should 4be cleaned` washed, and dried immediately prior to application of the chromium surface.

It seems to be an advantage to have the work warmed, as can be accomplished by application of an ordinary electric heating pad thereto just prior to application of the chromium coating.

The operator must apply the chromium plating pad quickly and smoothly with rapid motion and even pressure` to obtain lustrous result. If the ad is left on the work without rubbing, ark deposits probably containing chromates are obtained. A good coating of chromium can be had in about one minute by proper manipulation of the moistcned pad. Rubber gloves should be worn, owing to the poisonous character of t-he chromium chemicals, and the outer pad will require frequent renewals. The results obtainable however justify the effort required, as it is not necessary to remove the metal object for repeated tank treatments as in the prior art. l

The chemicals (D) used for chromium plating may be proportioned as follows:

chemica'ls Examiner Puta The pad (C) may be prepared with said chemicals in same manner as specied for nickelling.

In this specification the word parte descriptive of proportions in chemical formulae means parts by weight.

The electric chromium pad should be redipped in the jar of hot water provided, as

much of the chromio acid becomes dissolved therein in use. After the work is ready and preferably warmed as aforesaid, the connected electric pad is promptly and rapidly rubbed over the work portions to be coated or recoated. A vigorous motion with heavy tion.

In any case of application of this invention, the completed work should be Washed with a sponge dipped in warm water and promptly dried. Flannel cloths of outing flannel material are suitable for drying, and vigorous rubbing` of finished work will bring out a lustrous appearance in a few minutes. The washing is desirable to remove traces of chemicals left on the work during the treatment.- In the case of chromium plating, the washing should be done'promptly after treatmentl and repeated until all traces of chromium chemicals are washed away from the plated surface.

My invention permits heavy current density and locallized application of the electric current, while the abrasive polish ingredient keeps the work in nascently receptive clean condition to receive the coating.

If by mistake, the operator permits the pad to remain at rest on the work so that a spotty deposit results, thiscan be corrected by rubbing over the spotty portions, o r by re-cleaning and re-treating as aforesaid. On certain dirty Work, results are facilitated by dipping the electric pad in pulverulent aluminum powder, as aluminum has great affinity for electrolytically released oxygen. For treating certain metals with chromium, I prefer to intermix aluminum powder in pulveru'- lent form with the abrasive polishing agent employed, and sprinkle said mixture on the moistened pad. By including a small portion of tin chloride, otassium bitartrate and tartaric acid, (less tian 5% of the chemical content of the electric pad), I have been able to re-nish directly over automobile bumper trim portions which showed iron rust spots prior to refinishing treatment. y

It ma be remarked that the combination provide affords superior results and that the crystals held in proximity to the anode maintain the electricpad in operative condition for a long time, the electrolyte formed in the moistem'ng water tending to reach a uniform strength promptly controlled by the solubilities of the chemicals.

Difficulties met with in tank treatments in which unequal deposits are thrown on the work are avoided 'by the present invention as the operator can build up deposits exactly where wanted and at sharp depressions or corners on the metal object where bath deposits often fail. A minimum amount of electrolyte is handled in the pad and all the current used is effective in the electro-plating, and assistin heating effect caused by the current passing thru the resistance afforded by the moistened pad. Even the poisonous chromium electrolyte is thereby handled in such restricted amount that fume dangers are largely avoided by this means.

In the case of metal hardware or other parts not already connected to the negative pole of a storage battery, the operator uses the clipped wire to connect same thereto and inishes the operations as set forth, moving the negative clip to` different portions of the work under treatment so as to permit the entire surface to be coated to be treated. The flexible nature of the pad C) permits odd shapes of articles to be reac led, and in general it will be observed that the ratio of active anode surface to the portion of the Work temporarily connected as cathode is equal to or greater than unity, whereby the desirable oxidation-reduction potential eiects at the anode and cathode are correctly maintained.

The general appearance of the electric pad and a suitablemode of use has already been describedin my aforesaid copending patent application. the present invention have been particularly pointed out. Various changes and modifications are permissible within the scope of the.

ap ended claims.

claim: v

1. A plating and olishing anode having a fabric vcover there or, concentrated chemicals in substantially solid form held within saidfabric cover, and a finely divided polishing powder combined with said vchemicals and proportioned to penetrate therethrough when said fabric cover'is wetted with water.

2. An electroplating and polishing device consisting of an electrode, a mixture of electrolyte forming chemicals and polishing powder held wrapped thereabout,a wrapper for .said chemicals and polishing powder,l and means to attach said electrode to a source of electric current. l

In witness whereof I have hereunto set my hand this 4th day of May, 192,8.

PHILIP E. EDELMAN.

The improvements of

Images