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A concern about the Prip's flux I made


I have made a batch of Prips flux following the recipe mentioned on
the list. I used 3 ounces of Boric Acid, 2 ounces of TSP and 2 ounces
of Borax. The boric acid was a commerical roach killer that listed
ingrediants: 99% orthoboric acid. 1% inert. I looked up orthoboric
acid and it apparently is the same stuff as boric acid. I know
there is an issue with a substitute for TSP, and I noticed a box of
"TSP with no phospates" next to the kind that I purchased which said
Tri Sodium Phosphate. So, I have the right TSP. It’s still being
sold in Ohio. I found Borateem at the grocery store, but I
purchased a brand called 20 muleteam Borax, because it was cheaper
and just a way cooler name. But I believe it is the correct stuff. I
have read nearly every post in the archive about Prip’s Flux. But
nowhere is it mentioned what color it should be. I was expecting a
clear liquid as noone mentioned anything about a color and all the
ingrediants were white. Mine is blue. Mind you, it’s not an ugly
shade of blue, it’s a pretty blue, like the blue in an acetylene
flame. I actually like it being blue, but is it supposed to be

Thanks in advance.


Hmmmm, this prompts me to post about my problems with Pripps too…

I tried using exactly the same ingredients as did you, including the
20 mule team borax, and couldn’t get the stuff to stay in solution.
It would disolve, turn (yes, me too) a lovely blueish color, and then
fall back out once it had completely cooled - usually a good couple
hours later. I tried boiling for long periods, adding copious amounts
of water, emailing Peter Rowe so many times I was afraid he’d
disconnect his computer , and made multiple batches with the
same result every time…solid white crystalization all around the
sides of the pot (or, in the first case, the glass jar I’d transfered
it into which then had to be tossed, crystals and all). I’d given up,
but since the topic has been brought up… :wink:

Anyone? Jessica in SF, where the storm has turned my garden into a
verdant floral paradise.

  Mine is blue.  I actually like it being blue, but is it supposed
to be blue? 

Yes, and no. The blue is that “1% inert” in the roach powder
(Roachpruf, I’ll bet). It doesn’t seem to do any harm. --Noel

Mine is blue.  Mind you, it's not an ugly shade of blue, it's a
pretty blue, like the blue in an acetylene flame.  I actually like
it being blue, but is it supposed to be blue? 

Mixed from pure chemicals, prips flux is colorless, mixing up to a
slightly murky clear color. The blue is what you get when you use
grocery store laundry aisle borax. 20 mule team, and sometimes
others (I don’t remember if borateem does too) include more than just
borax. while it’s mostly borax, you’ll note occasional light blue
crystals in the laundry product. These are whiteners, which are
essentially dyes, which fluoresce a bluish white under ultraviolet
or blue light. The result is the white fabrics look whiter, selling
more detergent. In your flux, it makes the flux blue. You may
consider it a fine addition to help the marketing appeal, since
colored liquids might sell better than clear ones. The blue dye has
no effect on the function of the flux, so don’t worry about it.

Peter Rowe


Oh, mine too, some of it falls out to the bottom, I think some of it
never was in solution. I don’t know if it is right or if it will
work, but I intend to just shake it up before using and before
pouring from one container to another to keep it in the same ratio
as the recipe calls for. It may clog the sprayer I want to use, and
it now makes sense to me why others were talking about special
sprayers and techniques to keep the sprayers from clogging up.

Also, I used 3,2,2 ounces which is about the same amounts given in
the recipe which was in grams. But instead of a liter of water, I
used 4 liters of water, because thats how big the wine jug was. I
had read that this was ok and some schools use this great a
dilution. Also I hoped to avoid the problems mentioned with keeping
it in solution. I suspect that something in one or more of the
"expedient" ingredients simply isn’t very soluble in water. Also, I
think borax and boric acid together make a buffer and tsp is basic
and I have hard water to begin with. It could be … well I’m
getting into water that is over my head here. I’m just not going to
worry about it.


Peter, your comments on the whiteners brought to mind an old war
story. When I was in the Navy, we used to add 1 quart of a Sky Blue
color paint to 5 gallons of white. Our engine spaces always looked
whiter and had to be repainted much less often, unless the officers
decided that we were bored.

I suppose the connection here is “perception”.

Thanks for the



Jessica, If you are discouraged with your results, you can
purchase pre made Pripp’s flux. It is available at (
It is reasonable in cost, $6.50 for 16oz, and you don’t have to mix
it yourself. Its’ a new product for Santa Fe Jewelers Supply and will
soon be posted on the web site. Order using stock #473048.



Hi, Some years ago, I got tired of the homemade stuff clogging up my
sprayers, etc., and have been very happy with the commercially made
Prip’s Flux, available through Grobet suppliers. Cindy Eid