How to Care for a PEX Flexible Build Plate

October 10, 2026

Wham Bam Flexi Plate with PEX build surface for Bambu Lab printers

A good flexible build plate is one of the nicest upgrades you can give your printer. Prints stick while they're printing, then pop right off with a gentle flex once they're cool. To keep it working that way, a little regular care goes a long way. Here's how to keep a PEX or other flexible build plate in great shape.

What is a PEX flexible build plate?

A flexible build plate is a thin spring steel sheet with a print surface on top. It sits on a magnetic base on your printer bed. PEX is Wham Bam's own polymer build surface. Like the popular PEI surfaces, it needs to be kept clean and free of oils to give you reliable adhesion. Wham Bam's PEX Flexi Plates come in sizes for most Bambu Lab printers, including 258 x 258 mm for the A1, X1, P1, P2S and X2D.

First-time prep

Wham Bam recommends prepping a brand new PEX surface before your first print:

Scuff it. Use 000 steel wool or a red composite abrasive pad (such as Scotch-Brite 7447) in small circles for about 4 to 5 minutes, until the whole surface has an even, satin matte look.
Clean it. Wipe the surface several times with 90% or higher isopropyl alcohol (IPA) and a fresh, clean paper towel.

That light scuffing gives the surface a consistent texture, which helps prints stick evenly and release more predictably.

Everyday cleaning between prints

A quick refresh: after removing your parts, give the surface a short scuff (about 10 seconds) with steel wool or the abrasive pad, then wipe with 90%+ IPA and fresh paper towels.
Use paper towels, not cloths. This one surprises people. Wham Bam specifically says not to use microfiber, rags, or wipes, because they can spread old residue right back onto the plate. A clean paper towel every time is the way to go.
Clean the magnetic base now and then too. A stray blob of plastic under the plate can make it sit unevenly.

Hands off: avoid fingerprints

The oils from your skin are one of the most common reasons prints suddenly stop sticking. Get in the habit of handling the plate by its edges or tabs, and try not to touch the print area. If you do leave fingerprints behind, a good IPA wipe usually takes care of them.

Deep cleaning when adhesion fades

IPA is great for quick cleanups, but over time some residue builds up that alcohol alone doesn't cut. If prints are starting to lift or the surface just isn't grabbing like it used to:

Wash the plate with warm water and a little regular dish soap (Wham Bam also mentions vinegar as an option).
Rinse well and dry completely with paper towels.
Finish with an IPA wipe before your next print.

Skip the acetone. Wham Bam warns that acetone will damage the surface.

Flexing prints off the right way

Wait until it's completely cool. Both the print and the plate should be fully cooled before you flex. Never flex the plate while it's still warm.
Flex gently. A light bend is usually all it takes. Never force a print off.
Don't over-bend. Spring steel is flexible, but bending it too far can leave a permanent kink, and a plate that won't sit flat will give you first-layer headaches.

A note on sticky filaments

Some materials, like PETG and ASA, can stick a little too well. Wham Bam recommends using a glue stick as a release layer with these, which helps protect both your print and your plate.

When to replace your build plate

Even with great care, build surfaces wear out. It's time for a new one when:

Prints won't stick even after a deep clean and fresh prep.
You see deep gouges, nozzle scars, or spots where the surface is peeling or bubbling.
The plate is bent or kinked and won't lie flat on the magnetic base.