Alcohol for boric acid

Jewelry Discussion
1

I have always made my boric acid/alcohol solution with denatured
alcohol. I have been given a ton of medical (isopropyl) alcohol.
Will that work the same as the usual jewelers boric acid/alcohol
solution?

Thanks.
Janet in Jerusalem

2

Janet- Isopropyl alcohol will NOT do. I worked in a busy trade shop
once where Ia 5 gallon drum of isopropyl alcohol was accidentally
delivered instead of denatured. My late mother was a chemist so I
pointed out to one of the bosses that it was not the same thing. He
disagreed and told us to use it any way. What a disaster. We lost a
half a days work before he finally relented and reordered.

Isopropyl alcohol has 20-30% water. it just doesn’t burn right.
Denatured has only 5%.

Have fun and make lots of jewelry.

Jo Haemer
timothywgreen.com

3

Been using isopropyl for 40 years. Yes most off the shelf is lower
alcohol content and will not work but even on the drugstore shelves
there is 91% available. That burns fine almost exactly like
denatured 95%… Just read the label. Gary

1 Like
4

isopropyl is safer than denatured. i learned too late denatured gets
in your lungs and can sit therei have no clue why but being a bench
jewelerfor 40 years, 8 years ago got tonsil cancerAs a precaution
use isopropyl I changed years alter

David S. Geller
JewelerProfit.com

5

The reason methanol is the preferred solvent for boric acid is it
holds twice as much boric acid as ethanol and three times as much as
isopropyl. While you can buy 99% isopropyl it is not common and
quite expensive. Mostly what you will find is the medical grade
which is 70% alcohol and 30% water. Doesn’t burn off very well at
all. As for the dangers of breathing the alcohol fumes THEY ARE ALL
TOXIC. You should not be using them in situations where you don’t
have good ventilation. Do not fool yourself into thinking that
because you are using isopropyl that you are somehow safer.

Boric acid solubility by weight percentage in three alcohols.

Methanol 22.66%

Ethanol 11.96% (Denatured alcohol is typically over 95% ethanol)

1-Propanol (isopropyl alcohol) 7.34 %

James Binnion
James Binnion Metal Arts

3 Likes
6

isopropyl is safer than denatured. i learned too late denatured gets
in your lungs and can sit therei have no clue why but being a bench
jewelerfor 40 years, 8 years ago got tonsil cancerAs a precaution use
isopropyl I changed years alter Denatured alcohol is a generic term.
Denatured alcohol can contain ethanol, isopropanol, methanol, or any
other type of alcohol. It is veryimportant to read the label andthe
SDS (Safety Data Sheet) so you understand what exactly you are
getting. Methanol is definitely the most unhealthy of the 3 listed
above and I recommend staying away from it if you can.

Bernadette Johnson

1 Like
7

Denatured alcohol is what I have used for 45 years…

1 Like
8 
Boric acid solubility by weight percentage in three alcohols.
Methanol 22.66% Ethanol 11.96% (Denatured alcohol is typically over
95% ethanol) 1-Propanol (isopropyl alcohol) 7.34 %

Thanks James! That is exactly the sort of info I was hoping
for…:-)… Is the kind one buys in jewelers’ supply stores
usually ethanol? In my part of the world it tends to be purple.

Janet in Jerusalem

1 Like
9

So… why not just use Prips Flux? It is not that hard to make. I’m
not too keen on having something that burns on the bench anyway.
I’ve used it, but Prips is better, and a heck of a lot safer. Moot
point for me. I mostly work in high-karet gold and switched to
Argentium a few years back :slight_smile: I’ve never had much of a comfort level
with the alcohol/boric acid thing… just a disaster waiting to
happen.

1 Like
10

Thankyou so much for this information
Very useful just a though …any tips on safe storage of methanol as I know it is super flammable ?

11

Don’t think we have Prips flux in uk but thanks anyway

12

Keep it in the container it comes in with the lid tightly closed. If the lid gets warped or dented or in some other way stops being air tight transfer it to any container with an air tight lid. It’s flammable but not corrosive, so no need for the container to be of a special material.

13

Prips is easy to make :slight_smile: Google it. I don’t think you can even buy it commercially. Then … there are commercial ceramic based barrier fluxes … but they cost lot if you are doing production work. Cuprinol comes to mind I’ve used Cuprinol, I’ve used Prips, I’ve used Borax in alcohol. I guess results vary, but they all do the same thing. Use a barrier flux of your choice. Flame control is very critical … neutral flame and never move it from the piece once you hit it. Get in HOT and get out FAST. You still get frigging deep firestain. One of the reasons I use Agentium … you get a bit of firscale … but none of that PIA firestain. But its a different alloy than standard sterling … love/hate for me. Has some nice characteristics under torch … some good, some bad. Works like gold to me … that low thermal transfer thing. Some thinks it is too white. Experiences vary. I have firestain bad enough to use it and live with the bad parts … that hot short thing is just ugly.

1 Like
14

Ummm … I saw July and though it was 2023 … lol. Really … I am gettng old.

15

Thankyou so much Elliot for our interesting and informative reply
sorry I only just picked it up.
Great Advice …that makes me feel a bit safer , at least It won’t be a highly flammable substance ……in a Glass bottle ……in my soldering space ….non corrosive always good to know. The more I have considered …I’m still not sure about alcohol in my forge.
That said I appreciate you sharing your knowledge , I’m always Super Cautious with Chemicals , I get Anxious using them (except pickle), ,…but I love some of their effects (:face_with_hand_over_mouth: especially with Etching )
I will look into prips I have used Argotect mixed with Meths
but I find meths fumes Choking (methylated spirits , purple colour in uk )
All the best