The back of plywood is damaged after cut or drill. How to prevent it?

Question

When I cut a piece plywood that I have, the front looks perfect, but the back is becomes completely damage and unpresentable. The same problem happens when I drill it.

I use a table saw and drill press.

How to prevent such damage?

Answer 1

put a piece of 2x4 under the board when you drill it.

the drill bit has to drill into the 2x4

clamp the board down against the 2x4 if you can

https://www.woodmagazine.com/woodworking-tips/techniques/sawing-solutions/pointers-for-perfect-plywood-cuts

use a fine toothed blade to cut the board

raise blade as high as possible

place board good-side-up

use masking tape ... cover cut line so that the blade cuts the tape in 1/2 lengthwise

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_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  < cut along dotted line
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Answer 2

For Drilling -

Drill a smaller pilot hole before you drill your final size hole, this will give you the ability to have the hole location visible on both sides of the board. Then switch to your final size bit and only drill part way through the existing pilot hole, turn the piece over and finish drilling the hole from the other side. When using a spade bit or auger bit, it has a pilot point so you can drill just until the pilot point penetrates through the other side of the board and stop so the rest of the bit has not drilled all the way through. Then turn over your board and use the small hole created by the pilot point to start drilling the hole to completion.

For cutting -

using tape helps but on some plywood it can tear some up/off the ply up as you pull the tape off. Using a finish blade with a high tooth count will help considerably. If you have a track saw or are using a straight edge you can use a utility knife to score the wood ( shallow cut )on the exit side along the line that the blade will be cutting. This will prevent the blade from lifting the ply up as it cuts up through the wood.

On a circular saw the blade is cutting the bottom side of the board first so the nicer or finish side of the board should be on BOTTOM ( on a table say it is the opposite, finished side up ) The point being that you want the blade to plunge into the finish side for a nice clean cut, the tear out happens on the side where the blade is exiting the cut. That is the side you tape and score.

Answer 3

Use drills for wood and not the regular ones(for the metal)! That's the first advice I have for woodworking. Use high turning speed and take slow cuts with drill press.

Answer 4

It's the wood. That looks like luaun plywood, which can be like that. Different wood varies.

Also, wood varies when coated. I would brush on a liberal coat of West System epoxy on the punch-through side, and I doubt there'd be any more splintering.

Or, since you're using a drill press anyway, drill pilot holes with the tape trick to keep them from splintering. Then set your depth so the drill bit can't go all the way through. Drill the holes from one side, flip it, drill them from the other. The pilot hole should keep you on center, and none of your main-hole drills will be punching through the far side.