Wet filament is the most common cause of failed prints — and the least often recognised. Below you will find specific drying temperatures and times for all Porima materials, straight from the manufacturer's data. No vague advice like “dry it until it works”.
How to tell that filament is wet
- Crackling and popping from the nozzle while printing — that is water evaporating
- Suddenly a lot more stringing, even though the settings haven't changed
- A matt, rough or “foamy” surface instead of a smooth one
- Weaker layer bonding — the print splits along the layers under little force
- Visible bubbles in the extruded material when you push it through by hand
If a spool has been sitting open for more than a few days, assume it has picked up moisture. Nylon can manage that within a few hours.
Drying table — Porima manufacturer data
| Material | Temperature | Time | Moisture sensitivity |
|---|---|---|---|
| PLA | 30–40 °C | 2–4 h | Low |
| Tough PLA (PLA+) | 30–40 °C | 2–4 h | Low |
| Hyper PLA+ | 30–40 °C | 2–4 h | Low |
| Silk PLA | 30–40 °C | 2–4 h | Low |
| PLA Premium | 30–40 °C | 2–4 h | Low |
| PLA Wood | 30–40 °C | 2–4 h | Low |
| PLA Stone | 30–40 °C | 2–4 h | Low |
| PLA Army | 30–40 °C | 2–4 h | Low |
| PLA / CF (carbon fibre) | 55 °C | 4 h | Low |
| PETG | 30–40 °C | 2–4 h | Low |
| PETG Transparent | 30–40 °C | 2–4 h | Low |
| HT PETG | 50–60 °C | 6–12 h | Low |
| ABS | 40–60 °C | 6–12 h | Low |
| ASA | 40–60 °C | 6–12 h | Low |
| ABS / CF | 40–60 °C | 6–12 h | Low |
| PC/ABS | 40–60 °C | 6–12 h | Low |
| TPU 98A / 95A | 40–60 °C | 2–4 h | Medium |
| PA — nylon | 65–80 °C | 8–12 h (mandatory) | High |
| HIPS | — | not required | Very low |
Source: Porima's FDM parameter table. The values apply to Porima filaments — for other brands treat them as a starting point.
How to dry
A filament dryer — the safest option
Set the temperature from the table and leave it for the time given. With nylon and engineering materials, dry while printing — PA can pick moisture back up faster than you can finish a larger model.
An oven — only with a thermometer
Most domestic ovens on their lowest setting actually run 20–30 °C hotter than the dial shows, and spike periodically. Put a separate thermometer inside the cavity and check it before you put a spool in. A fan-assisted setting helps keep the temperature even.
What not to do
- Do not exceed the temperature in the table. Above roughly 55–60 °C a PLA spool starts to soften and wrap around its own windings — the filament jams and snaps in the extruder.
- Do not dry TPU for longer than necessary or at high temperatures — elastomers fuse together between the windings.
- Do not use a microwave or a radiator. Uneven heating deforms the spool.
- Drying will not undo degradation that has already occurred — it only removes water.
How to store it so you don't dry it over and over
- After printing, put the spool back in a zip-lock bag with fresh silica gel
- An airtight container with a hygrometer — aim for below 20% RH
- Silica gel can be regenerated in the oven (around 120 °C, 2–3 h) — there is no need to buy new gel every time
- Keep engineering materials (PA, ABS/CF, HT PETG) in a dryer permanently, not on a shelf
- Unopened Porima spools are vacuum-packed — until you open them, they need no drying
Common mistakes
- Drying PLA at 60 °C “just to be sure”. More harm than good — 30–40 °C is enough.
- Two hours for nylon. Too short. PA needs 8–12 h at 65–80 °C, otherwise the effect is cosmetic.
- Drying it and then leaving it on a shelf for a week. You are back to square one.
- Raising the nozzle temperature instead of drying. That masks the symptom, it does not remove the water.