CPO over cracked plexi?

[coasternuts]

So I have to take vacation days just to work on my cabinet.  I am so close to the end I can taste it. (Tastes like chicken.) 

Wouldn't you know it?  I have drilled several holes through the plexi but then...boom!  I didn't drill in reverse. 

Would you put your cpo over a somewhat cracked plexi?

I am constructing my control panel such as found here: http://www.oscarcontrols.com/sinistar

[RayB]

If the plexi is flat against the wood and the crackes have no raised parts to them, then yes, leave it as is and overlay on top.

[Abomination]

if you decide to use the cracked plexi I would buy some plexi glue and glue the cracks shut so they dont spread.  In case you dont know the glue is very thin, almost water like and will suck itself into the cracks, its applied with a needle tip in the bottle.

[gdilly]

I cracked mine after all the holes were drilled and I was installing it.  I was so mad to I said forget it and put it on anyways.

Once I can't stand it anymore I wil get a couple more pieces cut (just in case)!

[Ken Layton]

Ummmm..... the purpose of the plexi is to put over the control panel overlay to protect the overlay. You never put a control panel overlay on top of a plexi.

[Xiaou2]

 Firstly,  drilling backwards is a myth.   Ive always drilled forwards with plexi..  tried drilling in reverse once - and that cracked the plexi.

 From the pic, it looks as if there are no clamps on the panel.   You will neen to clamp the plexi really well so that it will not move at all.  Any vibration can cause
the crack.

 Place some carboard or simular material between the clamp and plexi so it wont marr.   Clamp tight.. but not so tight it will crack.

 The key to keeping the plexi from cracking is: Fastest speed, slowest downward pressure. 

 With a high speed drill,  use at full speed.. and press downward so slow, that it may take something like 15seconds to create a small hole.  The speed will create heat, which will melt the plexi.  The teeth will remove the melted plexi. 

 Pressing down too fast,  and the plexi will not be melted enough.  A tooth may catch too deeply and make a crack.

 In reverse, the melted plexi will not always be removed, can cause a problem as it cools and hardens near the edges.  Can cause the the drill to skip and vibrate a crack.   

  Use a 'drill guide'  if you do not have a drill press.  They are about 30$.  Harbor freight might be cheaper.   These will keep the drill perfectly straight while you are drilling.  Any wobble or change in the position can cause a jump and crack. 

 

[Bones]

Ummmm..... the purpose of the plexi is to put over the control panel overlay to protect the overlay. You never put a control panel overlay on top of a plexi.

Yeah, what is the purpose of this thread/question? I am pretty lost here.

[coasternuts]

The purpose was to see if I can use my artwork over my cracked plexi.

According to Ken, no.  Never over artwork.  So I think Ken is not a fan of how Kelsey did his panel, http://www.oscarcontrols.com/sinistar.  I believe it is done this way so there are no screws/bolts showing on the panel and the controls are accessible under the artwork.

I'm still planning on doing it this way.  Maybe I'll regret it.  I can always build another. 

In response to Xiaou2, actually I finished the control panel by drilling in reverse and going slow.  I cracked it going forward.  You are right about the vibration causing the cracking however.  That is how it cracked.  Going too fast and forcing it with a larger drill bit.  It grabbed(probably because of your explanation), pulled, and cracked!

I'm working on it today, so if I can't find the plexi glue, I'll drill me another one.