Helen,…It does take awhile to get use to using Pripps flux but
once you get the hang of it, its pretty easy.
My first problem is knowing at what stage to spray on the flux.
The first thing you need to do is lightly sand all pieces being
soldered to remove any oils that might have been used during the
manufacturing process. This is especially crucial when using new
plate or wire. Then dip the pieces being soldered into denatured
alcohol. That cleans off any finger oils that might have accummulated
How long do you heat the piece before spraying it on?
After dipping it (or painting on the alcohol if its a large piece
that won’t fit into the alcohol pot) warm it with your torch. The
alcohol will flame off and warm the piece suffieiently.
(S)ometimes it just it goes on wet and it’s difficult to get
coverage so you still end up with the leopard spots and possible
After spraying or dipping it, immediately heat it with your torch.
The Pripps will turn white. Stop as soon as it turns white all over.
If there are spots where it did not take, spray (or brush) more
on…let it set for a few seconds (don’t breath the resultant vapors,
they are not good for you) and heat it again. By the second or third
time, the entire piece should be white. Do not over heat it. If it
begins to turn golden or yellow, you have over heated it. No big
problem but, the next time use less heat.
My second problem is that when I use Pripps, I can’t get anything to
Pripps flux is a protective flux…not a cleaning/wetting flux.
After you apply the Pripps, you can do your set up (you can handle
the pieces - no problem) and then must use a cleaning/wetting flux
such as Batterns, or one of the other liquid fluxes - BUT ONLY ON THE
JOIN. This should solve your problem with solder that won’t flow.
The third problem is that I’m having to heat everything even hotter
than usual in an attempt to get the solder to flow.
Not sure why this is happening. It could be contamination but I
doubt the Pripps has anything to do with it unless the borac acid in
the mix is interferring. Using the second flux should resolve that
Let me know if this solves your problem. We use both Pripps
(protective) and Batterns (cleaning/wetting) fluxes at the school all
the time and have no problem with solder flow if…everything is
clean, the torch has the right tip, etc, etc.