# Why can't I cut hollow core interior door with circular saw?



## Brandnewruins (Apr 22, 2009)

Alright, so I've built my wall and now I have a 32" wide rough opening and a very short height 72" I believe. I figured I'd go buy a 30" wide hollow core door for 20 bucks and just carefully shave off from the bottom what I don't need. I would probably fill the bottom with spray foam insulation and shave off excess to fortify the bottom and if the bottom gets a little gashed up in the cutting I don't really mind. Can I get an opinion or two before I go Do It My Way. This is not about looks, I just need a door for my room to shut when I study and sleep. Thanks in advance.


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## Scuba_Dave (Jan 16, 2009)

You can cut wood down to re-insert into the bottom of the door
My bathroom door is hollow & cut short, no bottom edge was ever re-installed

I would cut off a little off the top - not enough to get rid of support
Then the rest off the bottom


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## AllanJ (Nov 24, 2007)

If the saw blade hits the hollow part of the door, more than 2 inches or maybe 1-1/2 inches in from the original edge, the thin wood making up the door surface could splinter a lot and become quite ragged.

This splintering would be greatly reduced if the saw blade were very fine toothed, like 8 or more teeth per inch of circumference for a circular saw.


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## jpelzer (Feb 21, 2009)

Fine tooth, plus score the cut with a blade, then tape over it, then cut with the saw against a straightedge. It'll come out fine.


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## retired guy 60 (Jun 23, 2009)

I recommend a plywood blade. Hasn't got carbide teeth so it won't last long but doesn't splinter the wood.


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## jaros bros. (Jan 16, 2009)

Use a couple of tightly pressed layers of painters tape and a straight edge held in place with a clamp on both sides. Keep it steady with a new blade and follow the straightedge. Keep the blade depth just enough to slice through. You should have minimum chip out. You may need to slice a little off each end or you could just take it all off one and then slide a piece of milled lumber into place with glue and a few finish nails to secure it.


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## Brandnewruins (Apr 22, 2009)

*Thanks so much!*

Wow everyone, thanks for all the useful info! Confidence rising as we speak. Thanks so much again!


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## adpanko (Jun 18, 2009)

I agree with the poster that said to score the cut line with a razor first. Don't bother buying a new blade or anything. Just draw your cut line, then take a box cutter, Xacto knife or any other sharp razor, and score the cut line with a few passes. This will neatly cut through the wood fibers on the surface with great precision and zero tearout. Then, put some painters tape along your cut line (with the edge of the tape aligned with your cutline...keep the tape on the side of the door/cut that you're going to keep, not the scrap side). Then use the circular saw to make your cut. Be very careful and diligent to not cut into the tape and ruin the nice scoring you did. It would be even better if you clamped a straight edge on the door to guide your circular saw. When you take your tape off, don't pull it up 90 degrees from the surface of the door, as the tape may pull up some of the wood from along the cutline. Instead, pull off the tape flat to the door. The end result, if done properly, will be a cut door with as close to zero tearout as possible.


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## InPhase277 (Feb 9, 2008)

Mark, score, tape, then cut. Reinsert new piece in bottom if necessary.

Oops: Already been said.


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## Brandnewruins (Apr 22, 2009)

*Worked great!*

Heck yeah, the scoring and taping method worked great. Looks factory almost from a few feet away! Thanks so much everyone!


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## joan smith (Jul 15, 2009)

Maybe you could put a piece of 2x2 (which is 1 1/2 x 1 1/2) back in after you cut the door down and secure with small finish nails. Or if you cut off enough of the door to save the bottom piece of support that was in the door you may be able to reuse this.


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