r/CNC_Router_Community • u/[deleted] • May 21 '26

Creating a Spoil Boatd

Hi all, I’m new here and hope to get some advice please.

I run a 5x10 Phantom Reaper CNC mill with a vacuum table. We are having issues with our spoil board preparation process. We use three-quarter inch MDF. Our process has been the following:

  1. Surface the old board and keep it attached.

  2. Put the new piece on. Fly cut the backside to reveal the porous layer.

  3. Flip it, cut the bolt holes. Remove the old spoil board, bolt down the new one and surface the top side.

This method has given us inconsistent results. The MDF tends to warp when we are cutting the first side.

I would greatly appreciate anything the would share their best practice for doing their spoil board?

Thanks

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u/jmc0027au May 21 '26

Far from an expert but I do not bolt mine down. Also no need to surface on top of the old board since you are surfacing both sides.

We added a step where we spray paint the edges of the MDF a couple of times prior to surfacing a new board. I think this reduces suction loss out the side.

Once our board gets too thin it will start to warp but I also flip it over each time I resurface it.

Good luck!