Share tips you have come across

I assume all the above is done because no hot air tool is available?

Yes, but we all have a soldering iron available.

Just showing what is possible and sharing options and techniques.

With hot air, you ‘do’ have to protect surrounding components with Kapton tape as hot air is ‘not’ as targeted as an iron.

However, hot air has its place.

If you ever tried to remove an electrolytic SMD capacitor with a hot air wand, that capacitor can explode.

In which case you can use the aluminum strip method.

Flux, heat one lead and tilt the capacitor slipping the ‘strip’ under that lead; cool and remove the strip.

Heat the other lead pulling off the capacitor.


See post #776

You can easily remove air from your Solder Paste syringe with a piece of wire.

Syringe storage:

Once my Solder Paste syringe is load, I do not like to dismantle any part of it.

To prevent the paste from drying out make a DIY Luer Lock cap.

The Heat Shrink cap can be removed and re-used.

Using a 1 ml syringe over the 10 ml Solder Paste syringe makes the out flow more controllable.

If you are not doing too many PCBs, manual syringe depositing of solder paste is easy to do.

A 1 ml syringe is superior to a 10 ml syringe.

You can fill your 1 ml syringes from a 10 ml syringe; suggest you fill to the 0.3 – 0.4 ml level.

A “22 Gauge” tapered plastic needle is what I use most often; suggest you deposit enough solder paste to cover the whole “Component Pad”.

There is significantly less effort advancing the plunger when using a 1 ml syringe.

I use a two-handed method to hold the 1 ml syringe; a microscope makes the work easier too.

Although you can do an adequate job using only a syringe, a dispenser makes the process easier and more controllable.

The “Micro-Dot” dispenser is great for depositing solder paste and can be purchased from the following WEB site:

The YouTube videos here shows how easy the dispenser is to use:

To help my big fingers work with the 'Micro Dot dispenser' I made a “Spring Assist Fork”.

This helps me assemble this dispenser, I also added a “10 mm Washer” in front of the compression spring.

Following is a discussion for using Micro-Dot dispenser:


The great thing about the 'Micro-Dot Dispenser' is the piston springs back when you release the grip.

This takes the pressure off the solder paste and stops oozing.

No complicated compressed air machinery, no wires or motors. :slight_smile:

Laying down dots of paste is fast, accurate and the process is repeatable.

This is a good great ‘must have’ tool if you are doing a few boards and you don't have a stencil.

These YouTube videos give you an idea of how much paste is actually needed:



After using the tool for a few months, I had a problem with the dispenser insert pushing out of its mounting hole.

The solution was to solder a flange washer to the insert to prevent the insert from dislodging.

Since solder does not stick to stainless-steel (SS), use a SS M3 screw to keep the washer in place during the soldering process.

See the images below to see how to make the modification.

The manufacturer has said new batches will incorporate a flanged insert. :slight_smile:

This is an indispensable tool on my work bench so it’s nice to have it working again !

When you load a new 1 ml syringe from a 10 ml solder paste syringe, you first need to purge all the air from the setup.

  • Attach a 18-gauge blunt needle to the 10 ml syringe.
  • Advance the 10 ml syringe plunger until solder paste oozes out of this needle.
  • Move the 1 ml syringe plunger to about 0.1 ml.
  • Insert the blunt 18-gauge needle into the end of the 1 ml syringe until you touch the rubber plunger.
  • Push the 10 ml syringe plunger so solder paste starts to fill the 1 ml syringe.
  • As the 0.10 ml void fills, rotate the body of the 1 ml syringe so you fill the void and force out all the air.
  • Once you fill the end of the 1 ml syringe, pull out the 18-gauge needle.
  • Now that the 1 ml syringe is purged of air, advance its plunger until all the solder paste is completely expelled; after this point, ‘do not’ pull on the 1 ml syringe plunger.
  • Replace the 10 ml syringe 18-gauge needle with a Luer Lock coupler.
  • Fill the coupler with solder paste by advancing the 10 ml syringe plunger.
  • When the coupler is full of paste, connect it to the 1 ml syringe.
  • You can now finish filling the 1 ml syringe with solder paste; suggest you fill to 0.3 ml or 0.4 ml.

Unless you accidentally pull back on the 1 ml syringe plunger, you do not have to purge it again.

Waw! thanks for sharing new tips, very helpful!

Referring back to Post #250

I have changed the ‘Screw Vise’ design to what is described in the images below.

The new design creates a ‘Pinch Vise’.

A 2mm hole is drilled near the outer edge of one of the fender washers.

Install a 2mm X 4mm screw with nut in the hole, tighten.

‘Do not’ use the small washer that was previously between the two large washers.

Assemble the new ‘Pinch Vise’ as per the images, the two washers will now be at an angle to each other.

The tighter you screw the nylon standoff, the tighter the new Pinch Vise grips.

This design allows you to grip items from thousandths of an inch and larger.

For convenience, here is a collection of Logic Level MOSFETs in one PDF.

‘You’ must confirm the component characteristics in the original data sheets.

See PDF below:

Logic Level MOSFETs 20 07 17.pdf (1.32 MB)

Make a wire bending jig for your solderless breadboards.

Now you really don’t need to to cut the PCB at 45°, But doing so gives you two jigs from one board ;).

Make things easy to remember:
Red .2”
Orange .3”
Yellow .4”
Green .5”
Blue .6”
Violet .7”
Slate .8”
White .9”
Black 1.0”
Brown 1.1”

Okay, this is not an electronic or tool tip, but it is a ‘Software Tool Tip’.
If you are new to the Arduino IDE, you can make your code easier to get around if you use ‘Code Folding’.
Clicking on the + or – code folding buttons will expand and collapse your code making it easier to manage writing your sketches.



We usually place our Global variables in the area just above the setup() function.

If you place these variables between braces, { }, you can then code fold this area at the opening { bace + and - button.

"a little known fact that the Arduino IDE has auto-completion of previously used variable names using Ctrl + Enter so you do not have to retype them"



The most usefull forum thread i have ever read, at all time!

Thanks. Specially to larryd :)

Sexy looking COVID-19 mask @larryd.

Tom... :slight_smile:


Referring back to Post #250 and subsequent Post #758.

The below addition for the 'Pinch Vise' makes it much more user friendly.

Here we are adding a rubber spacer to keep the jaws open while not compressed.

3/18" O.D. 'Surgical Rubber Tubing' is cut to a height of 1/8" (spacer).

The 1/8" rubber spacer is placed over the 6-32 set screw, i.e. between the two washers, see images below.

When the finger nut (top nylon standoff) is loosened, the 1/8" rubber spacer opens our vise.

This pinch vise can still accommodate a PCB thickness down to a 4 thou object.

For more leverage when tightening the ‘Pinch Vise’, add a 10mm standoff to the offset screw.

Moving the ‘screw washer’ to the top position helps identify the ‘pinch point’ 180 degrees away.

Or just use a 10mm long screw :wink:

Sometimes all you need is ONE or TWO ‘Simple Logic Gate(s)’ to finish a design.

See attached PDF:
Simple Gates.pdf (508 KB)


Where were you when I needed one lousy NOT gate to finish my project last year? I got a 7400 IC (2 inputs tied to make it a NOT) and 3 wasted gates on that IC.

Where were you when I needed one lousy NOT gate to finish my project last year?