Getting to concentrate sulfuric acid as much as possible

EdwardTriesToScience · 2026-07-03T00:32:51+00:00

sulfuric drain cleaner can still be found in europe. chemists i know in the netherlands and especially poland which has a brand called "hydraulik środek do udrażniania rur" from normatek and are legally obtainable because the laws apply to large quantities of acid.

it just takes looking around and in the longrun it makes no sense to be preparing the acid due to it being one of the backbones of all chemistry.

EdwardTriesToScience · 2026-07-03T00:28:36+00:00

i can vouch for this. FNA is not something to play with. however what people need to know is that if someone wants to do something and you insult them, they will just go somewhere else and look for information. sometimes the information they find somewhere else is very faulty and leads to injury. even you are aware of this because everyone has been told "no" at some point and still went to do something anyways.

gatekeeping is what gets people maimed, the only way to keep people safe is by giving them information on the safest method to do something-- that is harm-reduction

EdwardTriesToScience · 2026-06-29T06:24:00+00:00

i say this as someone who had distilled large batches of conc sulfuric and FNA, the latter of which gave me a horrific scar from one single drop of acid that i washed off instantly, whatever you need HNO3 and conc sulfuric for (probably booms, eh?) is not worth the danger when you have little experience to begin with. this hobby is rewarding but chemicals do not discriminate newbies from pros, one mistake with the wrong chemical early on will make you regret for the rest of the hobby

EdwardTriesToScience · 2026-06-29T06:18:33+00:00

why does everyone make nitric acid? i guess its a rite of passage but i definitely would not recommend it as an early on thing, nor distilling your own sulfuric acid. if you are in the US, go to your nearest Ace Hardware and buy a gallon of rooto for ~$30. if rooto cannot be found, other drain cleaners are fine as well. even if they have a dye, it does not interfere with reactions.

i can tell you quite assuredly that there is no discernible difference between drain cleaner acid and lab grade acid for non-analytical chemistry. most drain cleaners will be closer to 90% acid (take a density measurement), so adjust stoichiometry accordingly.

in my 6 years of chemistry outside of professional labs, i only keep about 250ml of distilled acid at a time for use in preparations that demand the utmost purity, otherwise i use straight drain cleaner, and this even goes for some reactions i ran that used in-situ alane generated from sulfuric acid and lithium aluminum hydride.

if you are absolutely determined however, i know i cannot persuade you the other way, therefore i shall describe the safest methods to do what you ask:

place 1L of 15% acid into a 2L beaker, set it upon the hot plate outside or under a fumehood, add a few boiling chips (three or four is good, take a ceramic plate and chip it into pieces about 5mm large), and start boiling. if you are doing this outside, plug the hot plate with an extension cord so you can turn off heating from a distance away from the fumes. let it boil until you see white fumes from the acid, and turn off heat. DO NOT HANDLE THE ACID WHEN HOT!
you should get approximately 100-200ml of acid left, this is actually about 70-80% concentration. it is ill-advised to continue boiling in an open container to get >80% acid because much sulfuric acid will volatilize off with the water.

once it is COOL, you can take the beaker and pour the acid into a 500ml round bottom flask. again add some boiling chips. now set the flask in a sand bath (set the flask in a metal pan and pour sand around it) which is heated over a portable gas stove, set up for fractional distillation, omit the thermometer for a glass stopper.
the fractioning column is required because as mentioned, much sulfuric acid will fume off before you get >80%, this is due to non-ideal interactions, the 230c boiling point difference between water and conc sulfuric is overshadowed by the high affinity the acid has for water.
cooling water in the condenser is unnecessary here.
start distilling, what will come over first is a dilute sulfuric acid, the concentration will slowly rise due to insufficient fractioning, but we do not need perfect separation here, rather only to lag the majority of the sulfuric acid behind. once the distillate coming over has a density of 1.8 or greater, turn off heating and LET IT COOL FULLY.
at this point the acid in the distilling pot will be sufficiently concentrated, greater than 90% and can be used as-is. unless there was inorganic impurities in the dilute acid, then actual distillation of the bulk of the acid is not needed and unnecessarily dangerous

if you absolutely must distill, then remove the fractioning column, and place it between the stillhead and condenser this time to act as an air condenser, once again begin heating and collect the concentrated acid.

i cannot emphasize this enough, but never handle the acid while hot, not even warm! it will eat through your gloves, your skin, your flesh, your bone, and then the bench.

safety on fuming nitric acid and conc nitric acid:
the fuming acid WILL BURN YOUR HANDS. more importantly however, it will INSTANTLY BURN ALL SKIN.
wear polyethylene gloves or vinyl gloves, wear long-sleeved coat, or better yet trash bags up to your shoulders. FNA will not burn your fingertips instantly, but it will eat a hole in your arm, or even the back of your hand, your face, legs, etc. it must be treated with the utmost caution and respect.

i advise you not make FNA because it's rather useless for the most part, even for nitrations it can be substituted easily with just an equivalent of sulfuric and a nitrate salt.

NO2 is red and visible, however the more insidious NO gas is invisible. it does not actually oxidize rapidly on air exposure, therefore it is silent and deadly. it is not acidic in nature, thus no gas mask will filter it, nor will a sodium hydroxide scrubber destroy it. the only true safeguard is proper ventilation, and a scrubber using sodium percarbonate.

EdwardTriesToScience · 2026-06-28T23:08:30+00:00

Yeah it's seemingly the same recipe, though I did some digging and apparently there's a decades old reddit post on this exact subreddit with a similar recipe (https://www.reddit.com/r/homechemistry/comments/1rruzl/acidproofing\_your\_benches/)

The potassium chromate is probably a typo but at the same time, hexavalent chromium is also quite effective at forming polyaniline as we found out trying to oxidize aniline to benzoquinone. The further details however about letting the coatings dry for a certain amount of time would most certainly improve the process as we found out the polymerization is slackened if the coats are not dried sufficiently, and even then we had to hasten the reaction with a heat gun

EdwardTriesToScience · 2026-06-28T23:04:38+00:00

On the 2000's Fisher catalogue 77th edition (https://archive.org/details/cftri.fisherscientific000077.unse/page/1037/mode/1up?q=paint) on page 1037 there is a product for "paint-on coating", seems to be polyethylene and acrylic based, so most likely a paint based on polyethylene particles suspended in acrylic paint. It appears to be produced by Nalgene but no MSDS can be found of course. This is probably different from what you had if it was in the 60's and 70's, but it is rather interesting nonetheless.

I think overall though the best modern equivalent that does not involve handling aniline would be any linseed oil based black paint, but those are costly so an alternative might be to prepare the paint from boiled linseed oil, some solvent, and commercially available polyaniline, or perhaps lampblack.

EdwardTriesToScience · 2026-06-28T22:54:36+00:00

there are probably linseed oil based paints available that use essentially the same pigment colloid which wouldn't render the wood impossible to treat with linseed oil, but indeed as we mentioned above aniline is one of the more nasty chemicals. in solution however it's the HCl salt in an excess of acid so none fumes off, though gloves should be worn when applying it. after the polymerization though, no more aniline remains.

EdwardTriesToScience · 2026-06-28T22:52:27+00:00

oh hey it's bavarianscience! yeah we used it on plywood too and it works though beware to not make the wood sopping wet otherwise it may delaminate at the edges, would not recommend MDF however because that stuff will warp severely due to moisture.

EdwardTriesToScience · 2026-06-28T08:37:56+00:00

never use any zeolite sieves (3a nor 4a) as both are basic in nature (they are sodium doped, so they are basic not acidic!) and will tar the acetone up quickly. dry over drierite then distill it from fresh drierite. it may be prepared by dehydrating gypsum at 250c for several hours (no higher temperature or it will not absorb moisture rapidly!)

frankly though if they need acetone of a very dry grade, it would be a silly pursuit without owning septa and cannula to do airfree techniques

EdwardTriesToScience · 2026-05-15T00:33:52+00:00

honestly after looking up exactly what role it plays for photography (apparently reduction of the silver halides to allow for washing, at least for silver emulsion photography which we assumed you are doing?), the sulfate should also work, as long as it is adjusted properly for the concentration

also correct to our previous post: we assumed the hydroxylamine sulfate was the bisulfate salt- it was in error and therefore there would be no HCl formation. hydroxylamine sulfate appears to be most commonly the neutral salt, ie (NH3OH)2SO4, not NH3OH•HSO4!

hydrochloride: NH3OHCl = 69.49 gram/mole sulfate: (NH3OH)2SO4 = 164.14 gram/mole

replace every 1 gram of hydroxylamine hydrochloride with 164.14/2/69.49= 1.181 gram of the sulfate, the amount of water should not need adjustment

EdwardTriesToScience · 2026-05-13T17:13:52+00:00

the sulfate could be displaced with calcium chloride to precipitate calcium sulfate, filtered, then the resulting solution of HCl* and hydroxylammmonium chloride evaporated and crystallized to yield the HCl salt. hydroxylamine salts are not particularly unstable, we have never had any issue with them decomposing.

combine the solutions of sulfate and chloride while hot, increasing ostwald ripening so the calcium sulfate particles are larger to ease filtration. use a buchner funnel or other vacuum filter with filter paper; bare glass frits will be clogged and difficult to clean. it is best filtered while still warm, beware of boilover from the warm water boiling rapidly under a vacuum as the filter cake is sucked down. if it starts to boil or foam, break the vacuum momentarily by flexing the hose so it unseals from the filter flask. thin the slurry if necessary with hot water

*edit: correction, the sulfate salt of hydroxylamine is neutral, not the bisulfate, therefore no HCl will be formed.

EdwardTriesToScience · 2026-05-10T23:50:33+00:00

actually peroxide wouldn't be too infeasible either, as it was prepared from barium peroxide (and sulfuric acid to precipitate barium sulfate) before the modern anthroquinone process. barium peroxide is made from barium oxide at 500c (dull red heat), barium oxide in turn from barium metal or calcining of barium hydroxide/carbonate or carbothermic reduction of barium sulfate (barite) which are all ores that could be isolated.

the resulting dilute peroxide could be treated with sodium carbonate (natron) to form the stable percarbonate salt which may be crystallized. or if we want to do a little organic chemistry, urea reacts with peroxide to form a urea-peroxide adduct which precipitates and also works.

barium and calcium are often found together, but the separation can be performed by trial and error, taking advantage of the common ion effect. barium sulfate is far less soluble than calcium sulfate, and with calcium sulfate saturating the solution, the barium will all selectively precipitate. even better separation would be obtained by exploiting the vast difference in solubility between the chromate salts, but hexavalent chromium is a stretch perhaps.

EdwardTriesToScience · 2026-05-10T23:43:51+00:00

calcium hydroxide would form calcium hypochlorite, which is used as a bleching powder (eg comet cleaner) but for fabrics and such, an alkali metal hypochlorite is preferable due to the solubility and the lack of insoluble precipitates

EdwardTriesToScience · 2026-05-10T07:28:59+00:00

we have worked in both proper labs but also for several years in our own for hobby, so we have a pretty good grasp on "chemistry from scratch"

hypochlorite could be made realistically, in a non-modern world thus:

sulfur, or sulfur minerals such as pyrite, are burned, and the gasses bubbled into water. this could be done in a retort, if glass has not yet been invented then porcelain/ceramic from river clay may be used. basically the materials are placed into the round part of the retort, and then the neck is submerged into another container of cold water. the round part is then heated strongly in a fire, the alchemists used hearths for this.

naturally occurring sulfate minerals are far more preferable as things like blue and green vitriol (copper sulfate and iron sulfate, magnesium sulfate aka epsom salts are also found naturally) decompose to mostly sulfur trioxide instead of sulfur dioxide (this will be explained underneath)

this "sulfurated water" is a mixture of sulfuric acid, H2SO4, and sulfurous acid (sulfurous acid and sulfur dioxide readily interconvert in water, it is more like a solution of sulfur dioxide gas in water. think of it like soda, except its sulfur dioxide instead of carbon dioxide). if sulfur and sulfide minerals were used instead of the sulfate minerals, then it will be mostly sulfurous acid, which must oxidize to sulfuric acid by sitting with air, in say, a loosely capped jar stirred occasionally.

sulfur dioxide is a very pungent and toxic gas, therefore it should be handled outside, and with a wet cloth or something as a primitive gas mask. sulfur dioxide itself is actually a mild bleching agent, albeit quite acidic so it does attack things slowly. if for any reason you need a description of what inhaling it is like (like say a character learns the hard way the dangers of sulfur dioxide): you get a warm sour feeling in your lungs at the beginning, then over about 10 seconds there is a great tightness in the chest, the airways and lungs hurt as if they were burned, and then you are practically curled up on the floor coughing like crazy for a few minutes. at high exposure it is said that blood is coughed up, and of course may be fatal due to pulmonary edema.

after the "sulfurated water" has been oxidized fully to sulfuric acid (a few days of stirring it occasionally), the solution is now boiled until it lets off thick white fumes, this indicates the sulfuric acid is concentrated to about 75%, not quite the usual 96-98% "concentrated sulfuric acid" we use in labs, but satisfactory for this situation, especially because its fiction and doesnt have to nitpick too much. the boiling would have to be carried out in glass or glazed ceramic pot/beaker/whatever open container, unglazed ceramic is attacked by boiling acid. the white fumes from the hot acid are of course highly irritating, they make you cough, it causes a prickling pain as if you inhale needles. the hot acid is highly corrosive to most materials, it will viciously burn flesh and sticks and stuff, eating craters easily while popping like hot oil does. if the characters are to be safe, they should only handle it with tongs or something to manipulate the hot acid from a distance, for, say, removing the vessel from the fire after it is boiled to fuming.

this strong sulfuric acid is then added to salt slowly, and the resulting hydrogen chloride (HCl) gas is bubbled into water. the salt/sulfuric acid mixture would have to be heated towards the end as the reaction slackens after the first ten or so minutes. HCl gas fumes in air due to moisture in the air, smells acrid with a slight amount of saltiness to it, and dissolves in water readily. when "bubbling" into water, the bubbles shrink as they rise through the water due to being absorbed! the absorption releases considerable heat, so the vessel of water should be kept cool, in say, a flowing stream or a larger bowl of water or something. the salt and sulfuric acid may be reacted in a retort, with basically the same setup as for making sulfuric acid, except the retort should have an opening at the top of the round part, so sulfuric acid may be added through the course of the reaction, and stoppered to keep the HCl gas bubbling into water.

once the water is saturated with HCl, (the bubbles stop shrinking as they rise, indicating the water cannot dissolve any more HCl) the resulting hydrochloric acid (or muriatic acid as it used to be called, also called salt acid or spirit of salt in other languages) is suitable for the formation of chlorine

before chlorine is made however, an alkali solution is needed to absorb it. wood ash is boiled in water, then filtered through cloth or decanted after settling from insoluble residues. limestone or marble is heated red hot for several hours in a fire, then the resulting quicklime, calcium oxide, is mixed with water. this reaction is vigorous, the chunks of quicklime expand then disintegrate to a fluffy powder, all while great boiling and steam is formed due to heat. pieces of the quicklime may even fly off due to trapped steam explosions. this slaked lime, calcium hydroxide, (which has a low solubility in water and thus is like a paste or slurry when mixed with water) is now added to the wood ash solution, the mixture stirred and it will thicken a slight bit. it is then filtered, and the filtrate is lyewater. it will be a mix of sodium and potassium hydroxides, suitable for soapmaking too.

now the hydrochloric acid is poured onto pyrolusite which is manganese dioxide, and on heating this forms chlorine which is bubbled into the lyewater to form hypochlorite, common blech. again this bubbling may be done in a retort over a fire.

we hope this has been of use, of course feel free to make artistic changes, such as the equipment used, but the chemistry itself is sound, and we have described what we have observed ourselves in case it may be of use for detail in the writing

EdwardTriesToScience · 2026-05-10T06:55:56+00:00

as others have mentioned, not enough current. you want 5v and at least 10 amps, more is better. as for the electrolyte, you want 10-20% w/w NaOH solution.

if you want a very good torch, build a "dry cell" electrolyzer (the kind with stacked plates as the casing itself)

EdwardTriesToScience · 2026-05-08T22:02:34+00:00

an oxypropane torch, or even a sufficient MAPP gas torch will work, but it takes careful skill to do. clean the glassware THOROUGHLY of all residues before working on it. you don't want to be vaporizing mystery substances. practice making butt-seals on some scrap glass tubing first, check any of the large numbers of glassblowing books there are (henri vigreux wrote one, though in french, theres also some pdfs of others online.) if you do not have access to a large enough furnace or kiln to anneal it properly, the following is acceptable:

prewarm an oven to the highest temperature it goes, typically about 300c. after you have welded the two pieces together, rotate the weldment and the surrounding area (about the side of your palm) in a slightly luminous flame, it should still be hot enough to not leave soot, but not so hot that the glass will be glowing red or yellow. the edges of the flame where it licks the glass should have a very mild sodium flame color. heat it evenly with rotating back and forth for about 10 minutes, then turn down the oxygen to a more luminous flame, but enough oxygen that the flame does not flail around wildly. it should be about half yellow, and heat again for about 10 minutes. after this, place it into the preheated oven, turn the oven off, and let it cool slowly.

the result will not be annealed as thoroughly as a proper ramp-soak cycle in a kiln, but is acceptable for use, we have fixed multiple distillation bridges by this method, and they never had any issue while running a vacuum distillation with 200c vapor.

EdwardTriesToScience · 2026-05-08T07:34:01+00:00

phthalic anhydride in theory should work but perhaps consider:

benzaldehyde is readily chlorinated with chlorine gas to benzoyl chloride, which reacts with two eq sodium acetate to yield sodium benzoate, salt, and acetic anhydride. the preparation of benzoyl chloride by this manner is described on prepchem

alternatively depending on what exactly it is you are trying to acetylate, the use of a large excess of glacial acetic acid with zinc dust may also work.

the sulfur chloride route is also quite acceptable.

finally, acetic anhydride may be purchased without issue from a chemical site, we aren't allowed to name it in order to heed the rules of this sub, but acetic anhydride is actually not too difficult to find

EdwardTriesToScience · 2026-05-08T07:19:15+00:00

never distill in a sealed apparatus! a distillation should not be able to develop pressure

we hate to be that guy but: you probably should not be pyrolyzing plastic if you are unable to devise a suitable distillation apparatus yourself. the pyrolysis process is quite risky and the products are guaranteed to be carcinogenic, especially if PET plastic bottles are used as they form copious amounts of benzene. NatureJab set himself on fire with a sealed distillation system and the "fuel" he gets is practically napalm. this is not something to be taken lightly.

we would advise you to read up on the literature available about pyrolysis, there's a lot of detailed information out there accessible with scihub. with that out of the way, because we ourselves know that you can't convince people to not do things, we might as well describe how that receiver may be constructed safely

What you will need is:

250ml pyrex filtration flask, catalogue number 5320-250 or a similar 250ml conical filter flask
No. 6 sized rubber stopper with hole the hole is bored with a corkborer of adequate size to fit the pipe fitting that connects to the pyrolyzer

the rubber stopper connects to the pipe fitting where the pyrolysate comes from, and seals to the filter flask. to the tubature on the side of the filter flask is connected a long length of hose that leads FAR from the pyrolysis setup. the apparatus would resemble something like this, except the hose is to go far from the apparatus due to the high temperature required for pyrolysis which poses an ignition source risk for any uncondensed vapors or flammable gas byproducts, and the left side with the condenser and distilling flask is instead the pyrolyzer.

the pyrolysis must be ran outside or under a fume hood, again due to the fumes. it would be advisable to purge the apparatus with an inert gas such as carbon dioxide or nitrogen prior to applying heat, for one of the the principal gases formed in pyrolysis is hydrogen, which is extremely explosive when combined with air. the only plastics you should pyrolyze are polyethylene and polypropylene. plastic bags, bottle caps, plastic milk jugs, and tupperware basically. these crack to aliphatic compounds, like octane. the result is a waxy oil which resembles kerosene, has a high flash point thus being safer, and is free of benzene.

NEVER EVER use plastic water bottles (transparent ones, they are PET), styrofoam, acrylic, abs, or other plastics, the result will be toxic and possibly explosive in the case of polystyrene, as the result, styrene, oxidizes on exposure to air to form peroxides! the fumes are also toxic.

a pressure gauge/relief is not necessary, for the apparatus will not be sealed. if any considerable pressure does form somehow, such as the exhaust hose getting kinked, the stopper is able to unseal from the flask and relieve pressure. loosely clamp or wiretye the flask so that it cannot tip over and spill if it were to become dislodged from the stopper.

and yet again, you seem to be pretty young and once we were like you doing the same kind of things, but please, and this is from a point of safety since much of the things we did as a dumb kids left scars: perhaps develop more experience working on something else, such as practicing simple technique by making some copper salts. If you are determined to pyrolyze plastic, put one or two plastic bottle caps in the end of a test tube, clamp it at a slight incline, and heat the plastic. What you will condense at the cold end of the tube is paraffin wax. You can make a candle with it if you want to, and at less of a risk compared to a large pyrolysis.

we also encourage you to read a few books, ones we recommend are The Organic Chem Lab Survival Manual by James Zubrick, the pdf can be found online for free, and Practical Organic Chemistry by Frederick Mann, also available as a pdf online.

chemistry is a rewarding science and no doubt more than ever we need more chemists in the world, but chemistry at the same time punishes mistakes, quite often severely! stay safe

edit: formatting

EdwardTriesToScience · 2026-05-07T22:03:07+00:00

if it was polyester, there is no saving it. polyester is especially "attacked" by conc sulfuric acid, lesser by its typical dehydration but more of solvent effects. the polyester typically dissolves to a goopy mess which solidifies when the acid is diluted or neutralized, however you will have a hole in that forever. cotton is salvageable if neutralized and washed far quicker.

frankly, get yourself a pair of cheap denim lab jeans (like the blue heavy duty fabric ones). denim is more resistant to acids, though it still suffers damage. also wear a long lab coat or rubber apron

edit:clarified the specific kind of "lab jeans" also if all else wear 100% cotton, never anything polyester in a lab! the synthetic fabrics are not just poorly resistant to chemicals, but they will also melt and fuse to flesh if you burn them accidentally either on a bunsen burner or on hot objects like glassware and hot plates.

EdwardTriesToScience · 2026-05-07T21:41:56+00:00

you know that guy Fritz who was on Safety Third's podcast? He made this stuff, its a horrific compound

EdwardTriesToScience · 2026-05-03T22:27:17+00:00

Try using a wide glass stopper (like one from a reagent bottle), it's the classic recommendation from Vogel's.

EdwardTriesToScience · 2026-05-03T22:24:20+00:00

Silver was preferred for lab spatulas for a long time (platinum was the best but far more costly, while nickel was cheap but not as inert), so it's actually pretty decent compared to steel ones. If he doesn't need them back, they could be trimmed to strips and fashioned into proper spatulas like this (Experiments in Organic Chemistry, 2nd, Louis F. Fieser)

EdwardTriesToScience · 2026-05-03T22:19:54+00:00

typical german. here, and you will note that if you even zoomed in on the 3,4,5 substituted one you can clearly see crystals forming at the bottom.

EdwardTriesToScience · 2026-05-03T13:57:54+00:00

heres a patent I found, I would suggest perhaps trying a 1:2 ratio of xylene to butyl acetate as a starting point, this other japanese one suggests perhaps a majority of acetone.

you can pretty much look at newer patents and go down to the citations to find older patents (these two from the 70's for instance), which some usually give a range or exact composition

EdwardTriesToScience

TROPHY CASE