alcohol lamp

7/22/2019 Alcohol Lamp

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he ubiquitous alcohol lamp, or spirit lamp, seen being used to heat the contents of the re-

torts n t s e g t u engrav ng rom t e ront sp ece o Wort ngton Hoo ersFirst Boo in

C emistry or t e Use o Sc oo s an Fami ies Harper & Brot ers, New Yor , 1862), s one o

t e o est p eces o a oratory apparatus. T e ear est vers ons, urn ng o , an use n con-

junction with the blowpipe, were employed by goldsmiths in ancient Egypt for making jewelry.

A co o amps ave een present t roug out t e story o c em stry. T ere s even one nc u e n

v rtua y every c s c em stry set, or, not nc u e , rect ons are supp e or construct ng one. In

sp te o ts ong story, most a co o amps are not use proper y, resu t ng, most o ten, n oo ng o t e

fuel, leading to burning corks and other fire hazards, as well as corrosion of the metal parts. Additionally,ost commercially available alcohol lamps need to be modified for use in the microscopy laboratory,

w ere, n a t on to genera eat ng requ rements, t e ame nee s to e ma e sma er, n eep ng w t t e

sca e o m croc em ca g assware an tec n que. Amongst t e cons erat ons n ma ng an or mo y-

ng an a co o amp or m croscop ca use are: 1) s ze, capac ty, an orm o t e ue conta ner acete

unfaceted, globe-shaped, squat; glass, metal); (2) nature of the fuel and its temperature when burned; (3)

ue s an t e v s ty o t e r ames; 4) caps: groun -g ass, stee , a um num, rass; g ass oo , meta

oo ; 5) w c mater a : woven cotton, cotton str ng, g ass er; 6) w c s ze an s ape; 7) w c s ee

ec an sm; 8) w c s ee -t roug support: g ass, rass, copper, stee , ceram c; 9) porta ty; 10)

provision for pressure equalization.


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Common Faults with Alcohol Lamps and Their Use

T e t ree most common au ts w t a co o amps an t e r use n t e m croscopy a oratory are 1)

over ng 2) a ure to prov e or pressure equa zat on, an 3) use o too arge a w c , espec a y one

that is also not kept trimmed. Of these, the most important is the failure to provide for pressure equaliza-

t on. In tota y sea e systems, suc as t ose ustrate n F gure 1, c anges n temperature an atmo-

sp er c pressure w cause t e a co o amp to act e a qu arometer, orc ng t e a co o up an out

o t e w c ; even t e eat rom t e an w cause t e a co o to e r ven out, espec a y so w t anoverfilled lamp. Removing the ground-glass stopper, and lighting the lamp, will ignite the excess alcohol,

creat ng a re azar . We - es gne a co o amps ave a t ny o e r e t roug t e cap or cor to act

as a reat er tu e or vent to ma nta n equa pressure ns e o , an outs e o t e ue reservo r.

Over ng o t e amp w t ue s an eas y correcte m sta e. I t e amp reservo r s on y e

a out a way, or somew at more, t ere w e ess e oo o s os ng a co o up t e w c , w c sup-

port, or out of the pressure equalization vent when handling.

For m croscop ca use, t e w c s, as norma y supp e , are muc too arge. As sma er w c s o not

seem to e commerc a y supp e w t t ese amps, t e average amp nee s to e mo e . Insert ng a

s ort engt o narrow meta tu ng w t an ns e ameter a out t e s ze o cotton wrapp ng str ng s a

common expedient, if not the most pleasing aesthetically; such a modification is shown in the case of the

a co o amp on t e e t n F gure 1. Bot o t e amps n F gure 1 ac a vent or pressure equa zat on.

Lets oo at some examp es o a co o amps, an t en comment on t em.

Some Examples of Alcohol Lamps

F gure 1 ustrates two a co o amps oun n a typ ca n ustr a a oratory; t ey are ot g ass-stop-

pered, and employ a cork surmounted by a metal disc and wick support both show evidence of having

urne aroun t e cor , o ow ng oo ng; not ce a so t e u up o soot n t e groun -g ass cap on t e

e t, an t e genera corros on o t e meta parts. Bot ac a vent.

igure 1.


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F gure 2 ustrates, on t e e t, an a most new vers on o t e same n o g ass-stoppere a co o

amps as n F gure 1, ut w t a cor t at ts ower n t e nec . On t e r g t o F gure 2 s an examp e o

an alcohol lamp with a threaded neck, and an aluminum screw-threaded cap, with integral wick support,

and a loose-fitting aluminum hood. Neither lamp has a vent hole.

Figure 2

F gure 3 ustrates a Ba sam ott e t at as een converte nto an a co o amp; t e oo , w t

groun -g ass ase, s m ss ng per aps t at s w y someone converte t s conta ner. T e o e n t e cor

as not een ore stra g t, an t e w c oes not protru e enoug . T ere s no vent o e.

On the right, in Figure 3, is illustrated a replacement cap and wick assembly for an alcohol lamp with a

rea e nec . It eatures a capt ve w c cover, an t e w c en as een oun to prevent ray ng. T sassem y cou e mprove upon y r ng a 1 16 or sma er o e n t e top o t e meta screw cap, to

ac as a pressure ven .

F gure 3


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F gure 4

F gure 4 ustrates two examp es o acete ue reservo rs. T e acete eature s not mere y eco-

rat ve; t s an o es gn purpose y ma e so as to e a e to t p t e amp w e t s n use, as ustrate

by the lamp on the right. The reason for tilting the lamp while in use is so that when soldering, or using

the blowpipe, or when performing borax bead and microcosmic salt tests, or sharpening tungsten needles

w t mo ten so um n tr te, r pp ngs w not a on to t e w c , ext ngu s ng t e ame. T s sty e o

a co o amp s o ten ca e a Jewe ers A co o Lamp. T e ewe ers amp on t e e t as een tte

w t a cor , an mo e or m cro use. T e ewe ers amp on t e r g t emp oys a t rea e meta cap

and hood. Neither lamp has a vent hole, which would be a marked improvement.

F gure 5 ustrates severa es gns o w c s an t e r ee -t roug supports. T e rass ee -t rougon t e e t s pa re w t a woven g ass er w c ; t s tt ng rep aces a cor . T e woven-cotton w c on

t e r g t as een pa re w t a orme g ass ee -t roug support, w c wou ave to e tte t roug

a cork, or used without one. The upper wick assembly uses a combination glass and ceramic wick support,

paired with a glass fiber wick. All three of these are intended for contemporary oil-burning lamps used

or ecorat ve purposes, w t or w t out opt ona aromat erapy ntent ons, ut t ey can e a apte to t e

a oratory a co o amp. A vent o e s not genera y necessary w en us ng t ese w c supports, as t ey

t oose y n t e mout o t e reservo r anot er reason to avo over ng.

Figure 6 illustrates three alcohol lamps that are components of chemistry sets for youngsters; similar

a co o amps ave een supp e n suc ts or over 80 years. T e amps ustrate ere are a re a-

t ve y sma a out one ounce capac ty ut t at s ze s tota y a equate or ot t ese sets an or genera

m croscopy; n ee , s m ar amps are o ten a part o m croscope sets or youngsters. T e t ree ampshere are all 40-50 years old. The alcohol lamp on the left, from a Gilbert Chemistry Outfit, is fitted with an

arrangement or e ementary owp pe wor ; t e t p s constr cte to a narrow open ng, an n use a p ece

o ru er tu ng s tte to t e ower en , an t e user ows t roug t e ot er en o t e tu ng, eep-

ng t e c ee s u y pu e out, n a ng t roug t e nose n typ ca owp pe as on, so as to ma nta n

a stea y stream o a r to pro uce a very s arp, ntense y ot ame. T e a co o amp n t e m e, rom

a Gilbert Chemistry Outfit of a different era, is typical and unremarkable. The alcohol lamp on the right

s rom a C emcra t C em stry Out t Porter C em ca Company), an as t e mo e - n egen Porter

A co o Lamp; t e w c s a y n nee o tr mm ng! None o t ese amps eature a vent o e.


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Figure 5

F gure 6


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F gure 7 s a page rom a C emcra t C em stry Out t manua , escr ng an ustrat ng t e use o t e

owp pe eature o t e a co o amp.

Figure 7

F gure 8

F gure 8 s T e A co o Lamp page rom t e S cra t C em a Manua . T e text says Do not

to t e top o t e ott e an F t e amp ott e w t a co o on y to t e start o t e nec or ower. T e

Fill Line in the illustration is, however, too high. This manual also says The best fuel for the alcohol

lamp is any commercially available denatured ethyl alcohol (grain alcohol), available only by prescription. Do not use met y a co o woo a co o ) ecause t as a t ona po sonous propert es, sopropy

a co o s rea y ava a e, ut t w urn w t a sooty ame.


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F gures 9 an 10 are pages rom ot er Do- t-Yourse sources; nterest ng y, t e text n F gure 10

recommen s ma ng a w c cap rom a rass r e cartr ge t s re erence s rom a UNESCO source).

F gure 9


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F gure 10

It was S ort M croscop c Determ nat on o t e Ore M nera s , M.N. S ort, Geo og ca Survey Bu et n

14, USGPO, Was ngton, D.C., Secon E t on, 1940) w o ustrate an escr e t e use o a narrow

brass tube and cotton string to make an alcohol lamp for microchemical methods See Figure 11.

Figure 12 illustrates two British-made alcohol lamps both are excellent. The capacity of both lamps

s a out two ounces. T ey are ot mens ona y sta e, an ot emp oy groun -g ass oo s o erent

es gn. T e amp on t e e t as a oose y a n ceram c w c o er, an s vente y ts oose t. T eamp on t e r g t as a ema e-t rea e rass tt ng cemente to t e g ass nec , an a t rea e screw- n

brass top/wick holder, which oeshave a vent hole drilled through! Filled no more than about half way,

t s amp s ea or genera eat ng purposes. In Br ta n, t ese sp r t amps common y urn Met y -

ate Sp r t, o ten s g t y t nge w t Gent an V o et, as ustrate n F gure 12.


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Figure 11

F gure 12


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F gure 13 ustrates an nterest ng a co o amp or porta e or e use. It s part o a Wor War II

F e , Nee e Ster zat on K t. It s n c e -p ate rass, an t n t e ottom o a c garette-pac age-s ze,

front-opening metal box with this burner at the bottom, and an elongated, round-bottomed sterilization

tray on top, which was just large enough to hold one or two hypodermic needles. A quarter-ounce of al-

co o prov es enoug ue or t s amp to urn or one our. T s s t e a co o amp I use n my F e

K t.

I recent y a t e opportun ty to mo y a commerc a y-ava a e a co o amp or one o t e sta

members, and then two others on the staff also requested one. I started with the purchase of an alcoholamp rom McCrone M croscopes & Accessor es; t s amp s ustrate on t e e t n F gure 14. It s not

a a es gnsma , sta e, meta cap w c o er an oo ma e o rass; t e on y t ng t was m ss ng

or m croscop ca wor was a pressure-equa zat on vent, an a sma er w c . A vent was ma e y r ng

a 1/16 hole through the top of the cap. For the smaller wick I decided to custom-make a piece of brass

that would fit inside the supplied opening, but that would itself have a much smaller opening that would

accept a ne woven-cotton str ng, or a ne woven g ass er w c . T e custom-ma e p ece s s own y ng

etween t e two amps n F gure 14, an nsta e n t e amp on t e r g t.

F gure 13

F gure 14


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Spec ca y, t e outs e ameter o t e w c tu e was 0.275, an t e ns e ameter was ust un er

0.250. I starte y c uc ng a 2 engt o ameter rass ro nto my Un mat, a sma o y sts

athe, and turned a 5/32 length at the end down to 0.16 diameter. This end was then center drilled, and a

/32 hole was drilled something more than 1 deep. The rod was then turned down to 0.24. The other

en o t e ro was t en cut-o an ace so t at t was 1 ong, p us t e 5 32 extens on; t s s t e p ece

s own y ng own n F gure 14. T s a apter was t en epox e nto t e w c tu e, an t e new str ng w c

rea e t roug . F gure 15 s ows a c ose-up o t e comp ete mo cat on, w c re ucer an reat er

vent. As a final touch for my colleagues, I embellished the shoulder of their personal lamp with their ownn t a s, y emp oy ng a rap y rotat ng z rcon um ro c uc e nto a o y sts motor ze an too .

Fuel for the Alcohol Lamp

T e two est, an east expens ve ue s or t e a co o amps are enature et ano et y a co o ;

gra n a co o ), an met ano met y a co o ; woo a co o ; met y ate sp r t); ot can e c eap y o -ained at hardware stores or home-improvement centers. I have seen people use absolute ethyl alcohol in

e r a co o amps, ut, n a t on to e ng waste u o g -gra e et ano , t e sa vantage I see s t at

e ame pro uce w t a so ute a co o s non- um nous, so t at t s easy to orget t at t s urn ng, an

cu t to see t e ames mens ons. Denature et ano , w t out a e ye, seems to me to e more

commonly used in North America. In the British Isles, methylated spirit or meths is generally used.

et y ate sp r t as, as ts pr nc pa component, et ano >60% common y 90%) w c s enature

ma e unsu ta e or r n ng) y t e a t on o met ano


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uoresce n or a ue or purp e an ne ye. T ere are un re s o rec pes or enatur ng et ano .

In a t on to persona z ng ones own a co o amp w t t e r monogram, t s a so poss e to urt er

individualize ones alcohol lamp by adding a touch of dye to achieve some characteristic color, and to add

a few drops of ones favorite perfume or cologne to the fuel!

T ere are erences n t e eat o com ust on or erent a co o s, an t ere are we s tes t at treat

t e energy trans ormat ons n suc c em ca com ust on react ons, ut n pract ca use o t e a co o amp

t ey ma e tt e mater a erence.

Extinguishing the Alcohol Flame

I t e cap s s mp y p ace over t e ame, an e t t ere, yes, t e ame w e ext ngu s e ; owever,

as coo ng ta es p ace, a vacuum s orme , an ue w e suc e up t e w c , caus ng oo ng. To ex-

t ngu s t e ame proper y, t e cap s p ace over t e ame, e a can e snu er, unt t e re s out, t en

the cap is put aside for a few minutes until the apparatus cools, then the cap is finally replaced to retard

fuel evaporation.

Conclusion

T ere are s gn cant erences n t e temperature o var ous reg ons o a co o an can e ames,

an erent port ons are e t er more ox z ng or more re uc ng, ut t ese erences are est earne

by developing the technique that comes from using the various portions of the flame in borax bead tests,

c arcoa oc us ons, an owp pe ana ys s, as we as con uct ng su mat ons, me t ng po nt eterm -

nat ons, ecompos t ons, me t- ac s, an ot er t erma m croscopy proce ures. A goo oo or earn ng

t ese proce ures as app e to m nera s s,I enti cation an Qua itative Ana ysis o Minera s y Ors no

Smith (Van Nostrand, New Jersey; Second Edition, 1953).

The main, immediate improvements that can be made to all alcohol lamps is to provide a small vent

o e, an not t e ue reservo r more t an a out a way. Next, re uce t e w c s ze or t e requ re

sma er sca e o wor y mprov s ng or custom-ma ng a ameter-re uct on a apter.

alcohol lamp

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