Heat shrink tubing covers a solder joint with a tight insulating sleeve. Pick a tube a little larger than the joint: a 3 mm tube suits signal wire, while a 10 mm tube suits battery leads. Shrink it with a heat gun until it grips. Tape adds a second layer on joints that flex. This guide compares heat shrink sizes.
What size heat shrink fits a solder joint?
Pick a tube 2 mm larger than the joint before shrinking. A 3 mm tube suits signal wire, and a 4.5 mm tube suits servo leads.
A 7 mm tube suits motor wires, and a 10 mm tube suits battery leads. A 2:1 shrink ratio grips the joint tight.
How do you shrink tubing without damage?
Use a heat gun at 150 degrees C and move it along the tube. The tube shrinks in about 10 seconds per joint.
Never hold a flame on one spot, or the tube burns. Keep the gun 5 cm from the tube and rotate the wire.
When should you use an assortment pack?
An assortment pack gives 127 pieces in sizes from 2 to 10 mm. It covers a full season of joints in one box.
A 4-size pack gives 20 pieces of each size in red and black. It suits battery leads and larger joints.
What tape works with heat shrink?
Kapton tape handles high heat near 260 degrees C on motor windings. It comes in widths from 2 to 35 mm.
VHB foam tape bonds parts that vibrate, such as a flight controller. It is waterproof and shock-absorbing on a 5 mm foam layer.
How do you protect battery leads?
Slide a 10 mm tube over each lead before you solder the connector. Shrink it after the joint cools for 30 seconds.
Use red tube on positive leads and black tube on negative leads. Color coding stops a reversed plug on the bench.
How do you fix a joint that pulls loose?
Cut the old tube off and strip 5 mm of fresh wire. Re-solder the joint at 350 degrees C, then shrink a new tube over it.
Pull the wire with 2 kg of force to test the repair. A good joint holds, while a cold joint pulls free.
Frequently asked questions
Can I shrink tubing with a lighter?
You can, but a heat gun is safer. A lighter burns the tube and leaves soot on the joint.
What shrink ratio should I buy?
A 2:1 ratio suits most RC joints. It shrinks to half its size and grips the wire tight.
Does heat shrink expire?
No, but old tube can crack if stored in sun. Keep it in a dry box away from heat.
Can I use tape instead of heat shrink?
Tape works as a second layer, but it peels over time. Heat shrink is the primary cover on solder joints.
Parts used
Heat Shrink Tubing Assortment (127/1600 Pieces), $5.13. Heat shrink tubing kit for electrical wire insulation and solder joint protection. 2:1 polyolefin, flame retardant. Ships from NY, USA.
Heat Shrink Tubing Assortment, 4 Sizes, $15.95. Four heat shrink sizes across five packs (10mm in red and black), 20 pieces each, for clean solder joints and wire repairs.
Kapton High-Temp Tape, 2-35mm, $6.99. Kapton polyimide tape. Ships from NY, USA.
VHB Double-Sided Foam Tape, $5.99. VHB double-sided foam tape. Strong bond, waterproof, sound-dampening, and shock-absorbing. Works on a wide range of materials. Pick your width. Ships from NY, USA.
Flexible 14AWG Silicone Wire (20ft), $15.99. Flexible 14AWG silicone wire, 20 feet. For battery leads and high-current wiring. I check every roll before it ships.
10mm Heat Shrink Tubing, Black (5 Pieces), $1.99. 10mm black heat shrink tubing, 20 pre-cut pieces. For battery leads and larger joints. I check every pack before it ships.
10mm Heat Shrink Tubing, Red (5 Pieces), $1.99. 10mm red heat shrink tubing, 20 pre-cut pieces. Color-code your positive leads. I check every pack before it ships.
7mm Heat Shrink Tubing, Red (5 Pieces), $1.99. 7mm red heat shrink tubing, 20 pre-cut pieces. For motor wires and mid-size joints. I check every pack before it ships.
Copper Foil Tape 2in x 50ft, $24.99. Copper foil tape, 2 inches wide and 50 feet long.
XT60H Male + Female Connector Set with Sheath Housing, 10-Pair, $11.87. XT60H male + female bullet connector set with sheath housing : gold-plated copper, 60A max. 10-pair. Ships from NY, USA.
Related buying guides on Quality RC Parts
How to Choose Heat Shrink Tubing and Tape for RC Builds
How to Use Heat Shrink Tubing and Wire on FPV Builds
How to Choose Silicone Wire for Your RC Battery Leads
Browse all the guides on the Quality RC Parts Drone Guides hub, or start at the Quality RC Parts store.
Sources
- Adafruit: Guide to excellent soldering
- SparkFun: How to solder through-hole soldering
- PowerStream: Wire size and ampacity
Quality RC Parts stocks parts in New York, USA and ships in-stock orders in 1-2 business days.
Last updated: 2026-11-10.