Picture of Low Cost Circuit Board Pre-Heat workstation for Solder Re-work
Circuit board pre-heat workstations are very expensive, $350.00 - $2500.00.

The goal of this instructable is to demonstrate how to make a circuit board pre-heat workstation for around $50.00 with no special tools and the majority of materials from Home Depot and Harbor Freight Tools.

Special Warning - Note This project involves working with AC line voltage and high current.
If you have little experience working with household line current please get someone to help you with this project.

I will try to assist you with areas of caution, but you must be aware that AC current can be very dangerous.

By reading this Instructable you must be aware that I am not responsible for any injury or damage you may cause to yourself or your surroundings. (With the normal warnings out of the way, lets have some fun)

Step 1: Bill of Materials

Picture of Bill of Materials
Get your pad and pencil we are going shopping:

Some 1/4" and 1/2" plywood from Home Depot or Lowe's)
(Future upgrade, I want to build a metal case for the heat blower and circuit.)

1 $9.99 Heat Gun from Harbor Freight Tools

1 Three prong (grounded ac power cord)

1 1 1/2" copper elbow pipe fitting

1/4" square tubing - or whatever size you can get

4 machine screws, nuts and washers

Power cord wire hold down clamp - Electrical department

16 gage wire (assorted colors)

16 gage wire nut and wire terminal.

Special Warning! (You must use at least 16 gage wire for the high current side of the circuit)

Smaller gage wire for fan and low circuit side of the circuit

Roll of steel strap (electrical department, Home Depot)

1 3/4" or 2" hole saw

Electrical Components

Q4015LT Triac/Diac (Mouser, Digi-Key or similar)

Heat Sink (nut and bolt to fasten heat sink)
(I used Digi-Key part number HS107-HD)


.1 uF Capacitor (Ceramic at least 50V) (Mouser, Digi-Key, Radio Shack)

10K Resistor (at least 1/2 watt)

100K potentiometer (variable resistor) (at least 1/2 watt)

4 wire Terminal connector strip (Mouser, Digi-Key, Radio Shack)

5 wire Terminal strip (Mouser, Digi-Key, Radio Shack)

12V DC Fan 60 cm X 60 cm X 25 cm (Mouser, Digi-Key, Radio Shack)

Knob to fit potentiometer shaft (Mouser, Digi-Key, Radio Shack)
jpitz31 (author) 2 years ago
Hello Damion,

I recall that when I built the circuit I removed the inline resistor as it was taking way too many turns to ramp. Your load may be different then my heat gun. I would try a larger value pot or add a higher resistor in serial to the existing pot. That may slow down the ramp.


I'm having troubles with this circuit. As soon as I turn it on and adjust the pot in a very small increment it ramps to full power and the pot no longer controls it. its not even past a 1/4 turn. its like control circuit isn't there. I'm not a novice at following schematics it's wired right. I use the lower setting at 6.6A. Any ideas?
aata2 years ago
nice info
zmatija3 years ago
Can you upload schematic for regulator, web page is not accesible...please
jpitz31 (author)  zmatija3 years ago
Sorry zmatija,

I posted the link to the schematic years ago, It is no longer available and I no longer have the schematic. I would do some searching out on the web for circuits that are similar.


You have to love the Internet Archive (A.K.A. the Wayback machine) Here is a link to the website that had the schematics. I have also attached the schematics themselves for future reference.


jpitz31 (author)  tamagotono3 years ago
Very Cool tamagotono, Thanks for following up.

Very nice
Chris20486 years ago
I can't seem to find a (cheap) source of 5/2" copper elbows. Could I use something else (or bend something else)?
panstar16 years ago
I just bought a digital heat gun ,& I would use it b/c I can set the temp exactly. but you should have put a temp gauge to show the temp. the controller you made is basic a light dimmer couldn't you just buy one they are rated for a max of 660 watts ? well we all use what is more convent in our own situation !
Very good instructable Nice pics Good explaning I'm rating u 5
snowrobot7 years ago
Thank you. This is a very well done instructable.
jpitz31 (author)  snowrobot7 years ago
Thanks Joe
hahaHAHAHA! I just bought one of those heat guns from HFT. The first one broke the first time I used it, make sure you save your receipt. Not bad for $10.
jpitz31 (author)  sensoryhouse7 years ago
Yes, The first one I purchased died as well. But the second one has been going strong. I always purchase the 1 year warranty on HFT items. Thanks Joe
feralbeagle8 years ago
I found one of these at OSH
mrmath8 years ago
The title of this instructable makes it sound like a Doctoral Disertation. Not that it's a bad thing. It just reminds me of sitting at my bachelor's graduation reading the names of the disertations of the doctoral folks.
HamO8 years ago
Awesome!! Extremely well done instructable, great pix. Thanks for sharing this idea and construction.
jpitz31 (author)  HamO8 years ago
Thanks HamO, I like the mouse with the glasses and calipers. Joe Pitz