When designing the Logical Grow Platform (“LGP”) and its accessories, one of the questions that comes up often is:
“Do these parts need to be waterproof?”
The short answer is: most of them don’t.
The longer answer — and the more useful one — is below.
This page explains how to think about material selection and slicer settings for LGP parts, when waterproofing matters, and when it simply adds unnecessary complexity.
Start With the Right Expectation
3D printed parts are not injection molded.
They are layered structures, and by default they are water-resistant, not truly waterproof.
That’s perfectly fine for most uses in seed starting and indoor growing.
In the Logical Grow Platform, many components are intentionally designed to:
- Allow airflow
- Allow drainage
- Dry quickly
- Avoid trapping moisture
Trying to make every part watertight would actually work against those goals.
Which LGP Parts Do Not Need to Be Waterproof
The following components do not need special materials or slicer settings for waterproofing:
Lids / Humidity Covers
- These are exposed to condensation, not standing water
- Any moisture naturally runs off or evaporates
- Standard PLA or PETG prints are more than sufficient
Plug Cells / Pots
- Designed for drainage, not containment
- Small amounts of seepage are expected and harmless
- Porosity can actually help with airflow at the root zone
Funnels
- Used briefly, not for storage
- Water passes through immediately
- No need for sealing or special materials
For these parts, focus on:
- Print quality
- Strength
- Ease of printing
Not waterproofing.
Parts That May Benefit From Extra Water Resistance
Some components can reasonably benefit from improved water resistance:
Bottom Trays
- May hold water temporarily during bottom watering
- Benefit from slower seepage to allow proper wicking
- Should still drain fully after use
Containers Intended to Hold Liquid
- Small watering jugs
- Mixing containers for diluted fertilizer
These parts don’t need to be perfectly watertight forever — but they should be able to hold water long enough to be useful.
Material Selection: What to Use and Why
PLA (Default, and Totally Fine)
PLA is perfectly acceptable for most LGP components:
- Easy to print
- Dimensionally accurate
- Plenty strong for indoor use
For parts that don’t hold standing water, PLA is the simplest and most accessible choice.
Use PLA for:
- Lids
- Plug trays
- Cells
- Funnels
- Structural components
PETG (Better for Wet or Long-Term Use)
PETG offers:
- Better moisture resistance
- Improved layer adhesion
- More flexibility before cracking
It’s a good upgrade when:
- A part regularly contacts water
- You want extra durability
- The part may stay damp longer
Use PETG for:
- Bottom trays
- Small liquid containers
- Parts that see repeated watering cycles
ASA / ABS (Optional, Advanced)
These materials offer excellent durability but:
- Require enclosed printers
- Are harder to print cleanly
- Are unnecessary for most users
They’re only worth considering for:
- Long-term setups
- Higher temperatures
- Advanced users
Slicer Settings That Improve Water Resistance
If you want a part to be more water-resistant without sealing, slicer settings matter more than material choice.
Walls Matter More Than Infill
Water leaks through walls, not infill.
Recommended:
- 4–6 perimeters (or more for trays)
- Slightly wider extrusion widths
- Solid top and bottom layers
Layer Adhesion Is Key
Better layer bonding means fewer micro-gaps.
- Print on the warmer end of your filament’s temperature range
- Avoid excessive cooling on functional parts
- Slow down outer wall speed slightly if needed
Infill Is Secondary
- 40% infill is usually more than enough
- 100% infill is rarely necessary
- More walls beats more infill every time
When Sealing Makes Sense (and When It Doesn’t)
Sealing is only recommended for parts that:
- Are very small internally
- Need to hold liquid, not just contact it
- Will store diluted fertilizer or water for short periods
For these cases, a low-viscosity epoxy rinse coat is the most practical approach:
- Pour in
- Swirl
- Pour out
- Let cure
Sealing is not recommended for:
- Plug trays
- Cells
- Lids
- Parts designed to drain or breathe
If water can escape and dry naturally, sealing usually adds no benefit.
A Practical Rule of Thumb
If a part is meant to:
- Drain → don’t waterproof it
- Breathe → don’t waterproof it
- Hold water briefly → improve wall quality
- Store liquid → consider sealing
Simple decisions beat complicated fixes.
Final Thoughts
The Logical Grow Platform is designed around controlled water use, not containment.
Good drainage, airflow, and repeatable watering practices matter far more than perfect waterproofing. In most cases, standard materials and sensible slicer settings are all you need.
Save sealing and specialty materials for the few parts that truly benefit from them — and keep the rest simple, reliable, and easy to print.