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Making the flux


#1

I’m trying to make some flux for soldering.

It seems I can’t find materials containing boric acid or TSP. My
local Wal-Mart seems to have phased out insecticides, cleaners, and
antiseptics containing this products.

But I have heard that borax powder, which I have, can be dissolved in
alcohol and would also work when atomized across the silver.

Would 90% isopropyl rubbing alcohol be safe to use for dissolving the
borax into?

Thanks,
Andrew Jonathan Fine


#2
But I have heard that borax powder, which I have, can be dissolved
in alcohol and would also work when atomized across the silver. 

Nope, not recommended.

Here’s a post about it:

http://www.ganoksin.com/gnkurl/ep7zl8

and one on where to buy:

http://www.ganoksin.com/gnkurl/ep7zl9

Would 90% isopropyl rubbing alcohol be safe to use for dissolving
the borax into? 

Nope, not recommended.

Hardware stores sell the denatured alcohol, you’ll find it. Please
order the boric acid from a jewelry supply place. I imagine you’re
waiting to use the boric acid and alcohol because it’s the cheapest
flux. It will work if you use the right stuff. Good luck.

Elaine
CreativeTextureTools.com


#3

Andrew- Isopropyl alcohol will not do. It doesn’t burn clean enough.
I worked in a busy trade shop once that had the wrong 10 gallon drum
alcohol delivered. It burned green and we lost a half a day of work.
You can buy denatured alcohol at any hardware store or painter’s
supply place. The same with TSP. The coarser granular boric acid you
can buy in a grocery store. Like 20 Mule Team Borax. It is only good
for casting or pouring ingots. You’ll need finely powdered boric
acid that you can buy from a pharmacy for a lot of money or you can
buy it from your favorite jewelry supply house for a bit less.

Have fun and make lots of jewelry.
Jo Haemer
timothywgreen.com


#4

Andrew, a local hardware store should carry TSP - it is used for
washing down walls amongst other things prior to painting or
wallpapering. Boric acid you should be able to find in a pharmacy
(chemist, drug store wherever you are). It is also used as an
antiseptic eye wash diluted with water (and used some this morning!)

Good luck!
Barbara on another breezy day on the island


#5
I can't find materials containing boric acid or TSP 

Any hardwarer store will carry TSP as a prep for painting.

The easiest and cheapest way to get boric acid is “Roach Powder” that
comes in a tall squeeze bottle. I know Walgreen’s carries it…


#6

Hi, Andrew–

I'm trying to make some flux for soldering. 

Let’s clarify what you mean by “flux for soldering.” Based on the
ingredients you are seeking, it sounds like you want to make Prip’s
flux–which is great. It’s just that if you have too much trouble
finding those ingredients and want to try an alternative, we should
be clear on what you are trying to do.

I know you may well know this, but since you didn’t say: Prip’s flux
is mainly used to protect sterling silver from firescale. I’ve heard
(though I don’t know from experience) that it is not very good for
fluxing the actual solder joints. So what many people, including me,
do, is use paste flux on the joints, and Prip’s flux, or some
alternative, on the rest of the piece.

BTW, boric acid is widely available under the brand name
Roach-Prufe. It’s not 100% boric acid, but close enough to make a
good flux. I’ve been using it in my homemade Prip’s flux with very
good results: as long as the metal is coated thoroughly and evenly, I
get almost no firescale.

If you don’t have a hardware store in your area, Home Depot or
Lowe’s might have the ingredients.

Matt Gushee
Studio Yanagi
studioyanagi.com


#7

Borax is virtually insoluble in alcohol. Boric acid is most soluble
in methanol, then ethanol, then isopropyl alcohol. You can buy boric
acid from mcmaster.com

James Binnion
James Binnion Metal Arts


#8
I'm trying to make some flux for soldering. 

It sounds like you’re trying to make Pripps flux. Check the archives
and follow the formula without substitutions. Remember that Pripps
flux is a protective flux…not a cleaning/wetting flux. You will
still need a cleaning/wetting flux (like Batterns-cheap) for the
places where you want the solder to flow.


#9

Add a little water to the borax and then the alcohol and it dissolves
fine and works great at a fraction of the cost of what the ones you
buy already to be used… just takes a second or two for the alcohol
to burn off before you put your face too close to the piece :slight_smile: Been
using it for over 40 years now and still doing fine…

Vernon Wilson


#10
Any hardwarer store will carry TSP as a prep for painting. 

But look carefully. The same hardware store will have other
detergent products which try to look like TSP and claim to do the
same thing.

Al Balmer
Pine City, NY


#11
You can buy boric acid from mcmaster.com 

Another source of boric acid is a local drug store or pest store.

Roach poison is typically 99% orthoboric acid.

Dave


#12

TSP is tri-sodium PHOSPHATE. Many states passed laws prohibiting use
of this as a means of limiting nutrient rich water pollution. So it
is not necessarily available where you live. Read the label
carefully, substitutes try to mimic the old label.

Stephen


#13
TSP is tri-sodium PHOSPHATE. Many states passed laws prohibiting
use of this as a means of limiting nutrient rich water pollution. 

Most states have restricted, not prohibited it. It may depend on the
particular product or its intended use. Here’s a useful link:

http://www.ganoksin.com/gnkurl/ep7zlv [PDF file]

Al Balmer
Pine City, NY


#14

Borax is available in almost every store that sells laundry
products. Pure Borax, look for it in the laundry soap isle…


#15

I checked Amazon and they sell both powdered boric acid and TSP. So
if it is difficult to find these locally or hard for you to get out,
let the nice UPS truck bring you the supplies.

Judy Hoch