A microwave kiln is a lidded box of heat-resistant fiber with a coating inside that absorbs microwave energy and turns it into heat. You set a small piece of glass inside, run your microwave for a few minutes, and the glass fuses. It is a fun, cheap way into glass jewelry. It is not a pottery kiln, and no microwave kiln we found claims to fire pottery clay.
This review is research-based. We read the Fuseworks product page and its user manual, a Hensom retailer listing and our earlier Amazon research, and we checked the numbers against Orton's pyrometric cone chart. We did not fire these kilns. This page is written for potters who saw a microwave kiln advertised and wondered if it could replace a real kiln.
Verdict: buy one for glass, not for pottery
For fused glass pendants, cabochons and earrings, a microwave kiln does the job quickly and for little money. Fuseworks says a fuse takes as little as 3 minutes in an 800 to 1,200 watt microwave.
For pottery, it is the wrong tool. The Fuseworks manual says not to fire anything other than glass in its kiln. The highest figures we found, 1,600°F from Fuseworks and 1,650°F from a Hensom seller, fall well short of cone 06, the low end of pottery firing. A clay pinch pot taken to those temperatures would not become ceramic, and wet or thick clay could crack or burst from trapped steam.
Can a microwave kiln fire pottery clay?
No. Pottery clay turns into ceramic only when it reaches its firing cone, and that takes far more heat than a microwave kiln makes. The table compares published temperatures with Orton's cone chart (self-supporting cones heated at 108°F an hour).
| What you are firing | Temperature needed or reached | Source | Microwave kiln? |
|---|---|---|---|
| Fuseworks microwave kiln, inside | 1,400 to 1,600°F (760 to 871°C) | Fuseworks manual | This is its range |
| Hensom large microwave kiln | 1,650°F (899°C) maximum | Retailer listing | This is its range |
| Low-fire clay, cone 06 | 1,828°F (998°C) | Orton chart | No |
| Low-fire clay, cone 04 | 1,945°F (1,063°C) | Orton chart | No |
| Mid-fire stoneware, cone 6 | 2,232°F (1,222°C) | Orton chart | No |
| High-fire stoneware and porcelain, cone 10 | 2,345°F (1,285°C) | Orton chart | No |
Temperature is only half the problem. Pottery firings also need a slow, controlled climb so water and organic matter burn out before the clay vitrifies, then a controlled cool. A microwave kiln has no thermocouple, no controller and no hold, just your microwave's timer. Our pottery cone chart explains why heating rate changes the cone temperature.
Do not put pottery clay, glazed bisqueware, metal objects or anything other than the maker's approved glass in a microwave kiln. The Fuseworks manual limits its kiln to glass and warns that the inside reaches 1,400 to 1,600°F. Wear heat-resistant gloves, set the hot kiln only on a non-combustible surface, never leave the microwave running unattended, and keep children under 16 away unless an adult is supervising closely.
How hot does a microwave kiln get?
Fuseworks states 1,400 to 1,600°F (760 to 871°C) inside its kiln. A retailer selling the larger Hensom kiln lists 1,650°F (900°C) as the maximum. Neither maker publishes a temperature-versus-time curve, and the real figure depends on your microwave's wattage, the kiln's age and how long you run it. Fusing glass needs far less heat than firing clay, which is why these kilns work for glass and not for pottery.
What can you make in a microwave kiln?
- Fused glass jewelry: pendants, earrings, cabochons and small charms from compatible fusing glass. Fuseworks recommends its own 90 COE glass and warns that mixing glass types causes cracking.
- Small glass embellishments: pieces to glue onto cards, frames or mosaics.
- Metal clay, with caution: some sellers market microwave kilns for silver clay. The Fuseworks manual says not to fire metals in its kiln, so follow the instructions of the kiln and the metal clay maker you use. A small electric kiln such as the Paragon SC-2 is the documented route for metal clay.
Things you cannot make: pottery, glazed mugs, bisqueware, slumped bowls larger than the chamber, or anything bigger than about 2.75 inches across in the Fuseworks kiln.
Microwave kiln specs compared
| Kiln | Type | Chamber | Max temp | Power | Price |
|---|---|---|---|---|---|
| Fuseworks FW849 | Microwave | 2.75 in platform, 1.75 in high | 1,400 to 1,600°F (manual) | 800 to 1,200 W microwave | Check price |
| Hensom Large | Microwave | 13.5 x 4.5 cm | 1,650°F (retailer) | Not published by the maker | Check price |
| Fuseworks Craft Kiln | Electric, 110V | 8.5 in wide, 3.5 in deep | Not published by the maker | 10A, 1,200 W | Check price |
| Skutt Firebox 8x6 LT | Electric, 115V | 8 x 8 x 6.5 in | Cone 6, 2,250°F (1,232°C) | 15A, 1,800 W | Check price |
Fuseworks FW849 microwave kiln
The FW849 is the best-known microwave kiln in the US. It is picked here because the maker publishes a full manual with temperatures, timings and safety rules. The fusing platform is 2.75 inches across with 1.75 inches of height, the kiln weighs 1.5 lb, and Fuseworks says it needs an 800 to 1,200 W microwave. The manual says to pre-fire the empty kiln for 3 minutes, fuse in 2 to 4 minutes, then leave the lid on for 30 to 50 minutes of cooling.
- Microwave needed: 800 to 1,200 W, with 3 in of clearance above the kiln
- Chamber: 2.75 in platform, 1.75 in high
- Inside temperature: 1,400 to 1,600°F (760 to 871°C) per manual
- Fuse time: 2 to 4 minutes, plus 30 to 50 minutes cooling
- Approved use: fusing glass only (Fuseworks 90 COE recommended)
- Price band: typically $150 to $185 in our September 2026 research; check the live price
Pros
- Fast
- Cheap entry to glass fusing
- Clear manual
Cons
- Tiny chamber
- Glass only per the maker
- No temperature control
Who should skip it: Anyone who wants to fire clay, slump bowls or make pieces wider than about 2.5 inches.
A newer Amazon listing, Fuseworks Microwave Kiln 2.75 in, appears to be the same kiln; we could not confirm whether anything differs. The Fuseworks glass fusing starter kit bundles the kiln with supplies, but we could not confirm the full contents from a spec page.
Hensom large microwave kiln
The Hensom kiln is picked for its larger chamber: 13.5 cm across and 4.5 cm high inside, in a 19.5 x 11 cm fiber body weighing 1.5 kg. A retailer lists a 1,650°F (900°C) maximum and 6 to 8 minutes per fuse. The listing also warns to use kiln paper, keep the kiln dry, avoid opening it while it cools and never set the hot kiln on plastic or wood.
Pros
- Larger chamber than Fuseworks
- Lower price band of about $100 to $120
Cons
- Generic brand
- Microwave wattage not stated
- Temperature figure comes from a retailer, not a maker manual
Who should skip it: Beginners who want a detailed manual; the Fuseworks kiln has one.
Fuseworks Craft Kiln: an electric step up for glass
The Craft Kiln is not a microwave kiln. It is a small 110V electric kiln (10A, 1,200 W) with an 8.5 inch chamber, 3.5 inches deep, a self-regulated coil and a dial timer. Fuseworks lists glass fusing, slumping, casting, enameling, silver metal clay and "glazed ceramics" among its uses, but publishes no maximum temperature and it has no programmable controller. Without a stated temperature you cannot know whether it reaches the cone your glaze needs, so do not treat it as a pottery kiln.
Pros
- Larger than microwave kilns
- Household plug
- Fuses in about 15 minutes
Cons
- No published maximum temperature
- Timer only
- Not for firing clay bodies
Who should skip it: Potters; spend the money toward a real small kiln instead.
What potters should buy instead
If you want to fire pottery at home on a small budget and a 120V outlet, look at small electric kilns with a published cone rating. The Skutt Firebox 8x6 LT reaches cone 6 on a 15A outlet, and the Paragon Caldera reaches cone 10 on a 5-15 plug. For real pottery loads, the Skutt KM-614-3 reaches cone 6 on a 20A circuit. See our best small kilns for the full list.
Not ready for a kiln? Air-dry clay needs no firing at all, though it is not waterproof or food safe. Our air-dry clay vs kiln clay comparison explains the trade-offs, and our guide to starting pottery at home covers firing at a community studio.
Weak points of microwave kilns
Results vary from one microwave to the next, because wattage, turntable size and age all change how fast the kiln heats. There is no thermocouple, so you judge the fuse by time and by peeking, which the manual limits because opening the lid early can crack the kiln and the glass. The fiber lining also wears: Fuseworks notes the coating may crack or blister over time, and it sells replacement tops and bases.
Who should buy a microwave kiln, and who should skip
Buy one if you want to make small fused glass jewelry on a kitchen counter, you already own an 800 to 1,200 W microwave you can spare, and you accept a tiny chamber. Skip it if your goal is pottery of any kind, if you want to slump or cast glass, or if you want precise temperature control. A small electric kiln covers all of those.
Many glass artists keep a separate microwave for kiln use rather than sharing the one they cook with. The Fuseworks manual warns against microwaves with plastic interiors.
Alternatives
- Paragon kilns: the SC-2 is a 120V kiln for metal clay and glass.
- Skutt kilns: Firebox models for glass, metal clay and small pottery.
- Pottery oven vs kiln: why a kitchen oven cannot fire clay either.
Sources: Fuseworks microwave kiln product page and user manual (Diamond Tech); Fuseworks Craft Kiln product page; Glytterati listing for the large microwave kiln sold as Hensom on Amazon; Orton pyrometric cone temperature chart (2016); Skutt Firebox 8x6 LT product page; Amazon listings for the Fuseworks and Hensom kilns. Specs checked October 2026.