[time-nuts] Soldering small stuff...

[Charles Steinmetz]

Burt wrote:

> I have an AM-SCOPE 7-35 magnification stereo microscope. I also have an
> OptiVisor with a 5x stereo lens that my son gave me about 10 years ago.
> As nice as the microscope is, I generally wind up using the OptiVisor.

Optics:
OptiVisors are *great*.  But there are lots of poor-quality imitations 
out there.  Accept no substitutes!  Buy Genuine Donegan OptiVisors 
*only*, with "DA-" series glass lens plates (blue lens frames) -- *not* 
the "LX" series with acrylic lenses in clear lens frames.

The one drawback of OptiVisors is that if you want higher power you have 
to settle for reduced working distance.  At some point, I don't really 
want my face that close to the hot iron and solder vapors.  For 
soldering, I find the DA-5 lens plate (2.5x at 8" working distance) is 
my practical limit.  A good stereo microscope (with reduced-power barlow 
lens) solves this problem.

BTW: Even 7x is *way* too much power for comfortable use as a soldering 
magnifier, IMO. You might want to try a 0.2x to 0.3x Barlow lens, such 
as the AmScope model SM03, which could make the experience much nicer. 
And possibly some lower-power eyepieces.

So:  How about a wearable version of the stereo microscope (best of both 
worlds)?

Those are called "surgical loupes."  And they are a pure joy to use. 
Once you try a pair of properly fitted and collimated surgical loupes, 
you will never go back to anything else for soldering small parts.

However: surgical loupes are moderately to very expensive, and it's hard 
to economize by buying used because they really need to be fitted and 
adjusted by an optician who knows what (s)he is doing or you may have 
eyestrain using them.  If you are optically knowledgeable and can figure 
out the misalignments for yourself (say, if you have sucessfully 
collimated a few pairs of binoculars), it is possible to self-fit them. 
  *Note* that the collimation problem arises with stereo microscopes as 
well -- many of the old venerable models you find used (B&L, AO) are 
badly out of alignment.

Soldering:
Finally, there is no need to flood IC pins with so much solder that you 
need solder braid to remove it.  The secrets are (1) use the right iron 
tip (a flat or slightly concave bevel tip is one of the best, but a 
spade will work); (2) keep the tip surgically clean; (3) keep the tip at 
the right temperature; and (4) use quality solder with plenty of flux. 
To see it done right (in less than 3-1/2 minutes), watch:

<https://www.youtube.com/watch?v=5uiroWBkdFY>


Best regards,

Charles