Question Scoring and Breaking Large Plexi

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Verdaccio

Verdaccio

MGF, Master Grumble Framer
Joined
Jan 22, 2007
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757
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Berthoud, Colorado
I have a job that is 30x80. It will be done with standard Premium Clear plexi. I have always had trouble with these large pieces that you have to score by hand and break by hand. Multiple times, they break either into the critical image area, or the scrap breaks into so many pieces that by the time I am done, it is good for only trash.

So thought I would ask for your experiences:

What tool(s) do you use to score plexi by hand - both for the scoring and bracing the score?

How do you go about breaking along the score without it running either into your image area, or breaking the outside scrap into multiple pieces? What is your process? Do you do it by yourself, or do you have human help?

Thanks for your insights! :)
 
Michael, the simplist way to assure a good score is to keep scoring until you have cut at least 1/3 of the way through the material. Usually 7-8 passes. I use a Fletcher hand held acrylic scoring tool, and a 96" metal straight edge I got from HD or Lowe's. The straight edge is clamped at either end, and held in place manually in the middle. I score the acrylic in sections, whatever is a comfortable distance, making sure to mark where I end the score. Once I've done that I will run the scoring tool through the score a couple more time with fairly light pressure to check for anamolies. I usually hang the waste edge off the bench at the score line and fold it downward until it breaks.
if I were going to be cutting a lot of full sheet acrylic, I would invest in a small diameter cordless circular saw and a plastic cutting blade.

For cuts 60" and less I use my fletcher wall cutter, and the built in breaking rollers.
 
Any good plexi scoring tool will work. You need to score the piece at least 1/3rd of the way thru the thickness for it to "break" properly.

I do mine on my Fletcher wall cutter. Once I've scored it enough, I pull the whole thing out of the machine and stand it upright with the score facing me and then grab each side of the score and begin to "bend" it back till it starts to crack. Keep bending and it will run down the whole piece and you just cut the paper from the backside and you're done.

If you are having it break or crack into the pieces, then you aren't scoring it deep enough.:thumbsup:
 
I've had the same problem at times. It seems to me to be not only the depth of the score but also the flex of the large piece. I don't know how Framah does that. The more flex I have the more likely it seems to run wrong. I do better on the large ones with help or by setting something on top of the plex near the score to hold it down like a section of 1 1/4 counter top I have or my C&H mat cutter.
 
wpfay said:
if I were going to be cutting a lot of full sheet acrylic, I would invest in a small diameter cordless circular saw and a plastic cutting blade.
Click to expand...

Here are a couple of threads that include some talk about cutting acrylic rather than scoring it.

http://thegrumble.com/showthread.php?59026-When-is-48x96-not-48x96

http://thegrumble.com/showthread.php?40169-Cutting-oversize-plexi

http://thegrumble.com/showthread.php?52401-trim-acrylic-1-8-quot-needed

http://thegrumble.com/showthread.php?61214-Plexi-Size-ARGH!

The investment to cut acrylic is minimal and the benefits are maximum.
 
For jobs that big I usually have my distributor cut it for me. They price cut plexi by the square foot. While the per-square-foot cost is higher than if I get a whole sheet and cut it myself, all the risk of spoilage is on them :) Do you have a distributor that offers this service?
 
For cuts over 60"

Place acrylic on bench

Measure & mark required width

Position straight edge to mark, clamp in place at edge of bench with F clamps

Use a Fletcher Terry Heavy Duty Handcutter

Score (twice, or three times)

Remove straight edge

Move acrylic to edge of bench, snap

Alternatives include table saw with adequate support, or circ saw with fenced straight edge, either one preferably with a plastics blade.
 
Something that size I either order cut to size or stop at Starbucks on my way over to my local glass guy and he'll cut it for me for a large latte.
 
question scoring and breaking large plexi.

Since I usually fail to plan ahead, I mark it with a sharpie and cut it with a jig saw. Makes big mess of plexi shavings but it gets the job done for the couple of times a year I need to cut one that does not fit in my wall cutter.....works for me.
 
I score the plexi by hand using the green Fletcher cutter. I score it way more times than anyone would think to be needed - usually ten - twelve times, just to be on the side of surety. Breaks cleanly every time.
 
Roger snaps large plexi on the basement floor, snapping it over a length of 1/2" diameter pipe from who-knows-where.
 
Thanks for your replies. You know you think you have it all in hand...and then you learn that there is actually a scoring tool...4+ years on...doing it with the backside of a box cutter blade. Now don't I feel silly. :P

Gonna have to get me one of those.

I like the ideas of clamping the straightedge and it idea of breaking it over a piece of pipe. :)
 
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