Skip to content

How-To: Use a Heat Gun

How-To get parts for your electronics hobby projects. You can recycle your obsolete electronic gadgets and learn about how these products are made at the same time. Useful parts to scrounge include surface mount and through hole components, microcontrollers, LCDs, connectors, digital and analog ICs, transistors, LEDs etc…

WARNING using a heat gun to de-solder parts is dangerous!

It’s fast and easy but not safe. The hot air gun is dangerous, the fumes can be toxic, and hot solder could end up in your eyes. Use eye protection, do this is an a ventilated area, and be very careful.

Two good warnings were received via the comment form on the Scrounging Electronics Project page. Note: The recommended heat gun does have temperature control but the warnings are still valid.

WARNING!! the hot air guns have no temperature control. If solder ( normally 37% lead ) is heated too hot the molten metals produce fume or vapor that may be extremely toxic. Lead can result in poisoning with symptoms of metallic taste, anemia, insomnia, weakness, constipation, abdominal pain, gastrointestinal disorders, joint and muscle pain, and muscular weakness, and may cause damage to the blood-forming organs, kidneys, nervous and reproductive systems. Damage may include reduced fertility in both men and women, damage to the fetus of exposed pregnant women, anemia, muscular weakness and kidneys.

OVER HEATING LEAD IS DANGEROUS! we are not talking about the smoke from flux during normal soldering.

Apart from the heat – also be careful of fumes. Do this in a well ventilated area – the solder, PCB coating and quite a few the items and processes used on commercially produced boards give off toxic – long term harm – fumes when reheated this way.

Tools needed:

All these tools are available at Home Depot. Here is a rough list.

  • Heat gun, Milwaukee 3300 about $40 at Home Depot. Look in the paint area. There is a cheaper model, MHT 1220, that should work but it does not have heat control.
  • Safety glasses (protect your eyes)
  • Cheap gloves (protect your hands)
  • Pliers, regular and long nose
  • Tweezers
  • Safe working surface. Click here to see how I made one.

Work Area:

A well ventilated area is a must. Also consider that the heat gun can burn any wood near the PCB your working on. You will need good light as well.

The beige metal plate shown in these pictures was made from a tower PC cover. Here is a how-to for making one of your own.

Temperature Control:

The recommended heat gun has a temperature control. Try the default setting of low/850F. If your gun does not have temperature control, you can lower the effective temperature by keeping the gun further away from the PCB.

Surface mount parts are designed to survive IR or hot air soldering. Though-hole parts should be removed from the bottom to protect the device.

Do not use more heat then necessary.You can easily destroy the PCB so be careful if you are trying to save the PCB. Too much heat can delaminate the PCB, burn it, and/or cause toxic fumes. Do not use too much heat. Have some patience.

Removing high pin count parts:

Any size surface mount part can be removed with patience. Use a lower setting to pre-heat the board area, then move in with higher heat to free up the pins.

For though-hole parts work from the bottom.Plastic parts such as connectors can be hard to remove without melting them.

Saving the PCB:

The PCB will be damaged if you apply too much heat. The board can delaminate or form bubbles on the surface, you can pull pads and traces and you can pull out feed-though connections.

To remove a part and preserve the PCB, make sure the solder is completely melted before pulling a part. Through-hole parts with placement or mounting pins can be especially hard to free without damaging the PCB. These oversize mounting pins are often designed to snap though a hole in the PCB and are common on connectors. It might be better to remove all the solder with wick from these pins, then cut them off close to the PCB. Assuming your not trying to save the connector.

Saving Plastic parts:

As you can see this connector was damaged. I did not notice that it was there when I was working on another part of the board. Watch where the heat is going!

All the though-hole parts that are sensitive to heat should be removed from the bottom with minimum heat first.

Heat sensitive surface mount parts are difficult to remove without damage. If you can sacrifice the PCB then use high heat from the bottom. The heat will flow through the PCB freeing the part. This will likely destroy the PCB.

Headers like the one shown are just about the hardest part to save.

2 Responses

Stay in touch with the conversation, subscribe to the RSS feed for comments on this post.

  1. Zen Punk says

    Headers like that are usually through-hole, so if you want to save it you could unsoldering and remove it with an iron and braid.

  2. Jim says

    Any advice on removing an 8-pin BIOS chip on a hard drive circuit board? Another video shows someone using a heat gun with a pencil-sized tip on it to heat a small area at once. Can those “pencil torch” tips be purchased separately, and attached to a regular heat gun, or is a special heat gun required? Should I shield adjacent areas with aluminum foil?

Some HTML is OK

or, reply to this post via trackback.