How to Cut a Builder’s Mirror

Posted on: April 13th, 2011 by Sandra Powell 23 Comments

cut builder mirror

After my failed attempt at cutting down my first builder’s mirror, I got a hold of 2 more and tried again (after watching some videos on the subject and buying a better scoring tool.)  I successfully cut them both.  One I cut into 7 pieces so I am sure it wasn’t just dumb luck.

cut a builders mirror


Here are some important things I learned.
1.  All cutters (scorers) are not equal.  I first used one that I bought at the local home improvement store.  They only had 1 to choose from.  It had 6 different tiny scoring blades on a wheel.
The new one I bought has one scoring wheel and a cavity in the handle for oil.
mirror cutting tools
I bought mine from Amazon.  The cutter was $20, which is high compared to some  but I tried the $5 option the first time and it sucked so I got the higher end model in order to give this test a fair shot at working.
Amazon affiliate links:  Fletcher Terry 01-711 Fluid Glass Cutter, Fletcher Terry 09-541 Fluid Glass Cutter

2.  Apparently you need oil!  Either on the mirror or on the scoring wheel or both.  I think you can use any kind of oil, sewing machine, cooking…not sure.  I just bought the oil that had the same brand name and was meant to be used with my new cutter.  (Because I wasn’t sure this would work and I wanted to do everything I could to make a good effort.)

3.  Clamp your straight edge down so it doesn’t wiggle around.  You need a firm guide to follow in order to score properly.
Cutting a builder mirror

What not to do:  I tried holding a piece of melamine as a straight edge which just slid around on top of the glass.  *You can use anything with a straight edge, just clamp it down before scoring.

4.  Make your score in ONE, CONTINUOUS, EVENLY PRESSURED MOTION!  DO NOT GO BACK OVER YOUR SCORE!   You might be tempted to go back and forth to make sure you got it.  Don’t do it!
Something about glass being in a state of flux between a solid and a liquid and once you score it it messes with the molecular configuration… Look it up if you’re interested in that much detail.  My eyes glaze over when instructions get too detailed so I’m not likely to pass on anything more than I absorbed.  The point is:  ONE CONTINUOUS, evenly pressured score all the way from the beginning of your mirror OFF the opposite end!
With my failed attempt, I could hear that the blade wasn’t making constant contact with the mirror so I went back and forth over my score line which was my biggest mistake, apparently.
5.  You can use special pliers (Glass Cutter Pliers) to snap your mirror if you’re making small “cuts” (technically they are breaks) but for larger “cuts”, just use the weight of the mirror to break itself.

So there you go.  It is possible to cut a builder’s mirror.

cut builder mirror
Not perfectly perhaps, but good enough for me.
There was a little chipping right along the edge but nothing a 1/4″ lip on a frame won’t hide so I’m totally happy.  It was actually quite fun!

Tags: ,

23 thoughts on “How to Cut a Builder’s Mirror

  1. Girl, this is awesome! I have THREE builder mirrors in my garage right now. Hubs wanted to throw them out last week and I said nooooo b/c I knew I could cut them down somehow & use them!! You rock. Great video by the way. I’m impressed!

  2. David H says:

    Good video. I like the look of trepidation and surprise when it actually worked. lol. Please use safety glasses though. It is not uncommon for little chips to come flying at you and it would be a real shame to get a little piece of glass in your eye.

    • Yes, good point. I am usually a sucker for safety but everything I read is that these mirrors wouldn’t chip and fly into your eyes. I did however, put on my goggles for subsequent cuts because I was nervous about that very thing. I thought I edited out all the trepidation though. LOL

  3. Amy says:

    I love Sawdust and Paper Scraps. She gives real life useful home improvement tutorials for ladies who arent afraid to get their hands dirty.

  4. Ashley @ says:

    while mirrors do not intimidate me, your tutorial is phenomenal, and the video is a great visual!!! Nicely done!

  5. becky says:

    I saw your post a few months ago, and was totally inspired. I went out and bought a glass cutter/scorer but then chickened out. :( Today I did it! I made my first cut, for practice, and am so excited about how easy it really is. Now I just need to get some clamps and a straight edge (I used duct tape but didn’t get close enough for a good straight cut). I am not going to frame the mirror when finished, any suggestions for finishing the cut edges?
    Thanks for the great ideas!

  6. This is a great post and exactly what I was looking for. Thanks Sandra.

  7. Ronda Batchelor says:

    We cut our mirrors for our master bathroom. We also broke a few but finally got it. Good tip about the oil.

  8. Joy2Journey says:

    I have a mirror and I am not afraid to cut it! :) Thanks for the video … I am going to do this for a project I am working on. Your the best!

    PS I really like where you are headed with your blog. You certainly found a unique nitch!

  9. Mhurrin says:

    This is a great video! I have an old sliding mirrored wardrope door which I don’t want to throw out ( the frame from around it has came of) iv kept it cause I wanted to cut it and frame it, I have googled it loads of times to see if anyone has done anything with a large mirror like this and your video is perfect, I did what you said and it turned out perfect! I now have 2 beautiful and very large framed mirrors tht everyone who sees them comments on thanxs so much for posting your vid it gave the the push I needed to get started.