What soldering iron do I need for model making?

A temperature-controlled iron with 15-40W is ideal. The Antex XS25 or Weller WE1010 are excellent choices. Avoid uncontrolled irons as they can overheat and damage small parts. A fine (1mm) tip is essential for most model work.

Should I use lead or lead-free solder?

Lead solder (60/40 tin-lead) is easier to work with and melts at a lower temperature. Lead-free solder is safer but needs higher temperatures and more skill. For model making, lead solder is generally preferred. Always wash hands after handling lead solder.

What is flux and why do I need it?

Flux cleans the metal surface and helps solder flow into the joint. Without flux, solder balls up and does not bond. Rosin flux (in cored solder) is adequate for copper wire and LEDs. For brass and nickel silver use a phosphoric-acid liquid flux such as Carr's Green or Yellow label — not a zinc-chloride "killed spirits"/plumber's flux, which is far more corrosive and harder to neutralise on fine etched parts. Always neutralise and clean off excess phosphoric flux with water or IPA after soldering.

How do I solder without melting plastic?

Solder metal parts before attaching to the model. Use heat sinks (crocodile clips) to draw heat away from nearby plastic. Work quickly — touch-and-go technique. Let joints cool before handling. Pre-tin parts separately, then join with minimal heat.

ModelCalcs

Soldering Calculator — Temperature & Tip Selection

Choose the right soldering iron temperature and tip size for model work.

TaskBrass/PE = etched kits & photo-etch (tin-lead). LED/Wire = lead-free, lower heat, LED-safe technique.

Joint SizeBigger joints sink more heat, so they need a hotter set-point and a larger chisel tip.

MaterialNickel silver needs more heat (poor conductor); copper sheds heat fastest (best conductor); both need the right flux.

How We Calculate This

Recommends soldering iron temperature, tip size, solder type and flux based on your task, joint size and material. The Temperature Tolerance option sets the ± workable band shown around each recommendation. Temperatures are tip set-points for a temperature-controlled iron: 60/40 tin-lead melts around 183-188°C, and the tip is run well above that (melt point + ~50°C + heat losses into the work) so the joint reaches wetting temperature quickly.

Temperature Guide

Brass etch/PE: 300-360°C depending on joint size
LED / wire: 280-350°C
Nickel silver: +20°C above brass — it conducts heat poorly (~25 W/m·K) so the iron must do more of the work
Copper: match brass — copper is the strongest heat sink (~400 W/m·K vs brass ~110), so for equal joint mass it needs at least as much heat; thin copper wire still tins easily because its mass is tiny

Frequently Asked Questions

Related Calculators

Drill Bit Size Calculator

Find the right drill bit size for pinning, rivet holes and detail work at scale.

Blade Selection Calculator

Choose the right hobby knife blade for cutting, scribing and trimming tasks.

Magnification Calculator

Calculate the magnification power needed for detail work at your scale.

Light Setup Calculator

Plan workbench lighting — lux levels, bulb count, colour temperature and positioning.

Cutting Mat Calculator

Find the right cutting mat size for your workspace and typical project sizes.

Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.