Plexi-Glass Screws?

[SirSteve 10+ year member]

What types of screws are best for plexi-glass? I'd like to have them counter-sunk as well. It will be a large piece 12x48 3/4" thick.

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[evo2k3 10+ year member]

is the plexi just one peice being screwed into mdf? if thats the case you use the same screws as you did everywhere else (mabey longer since the plexi is a little thicker. the holes through the plexi should be clear holes anyways and then just use your regular counter sink bit to counter sink them, pilot through the mdf and run your screws in....your not about to acheive as good of a bond between plexi and mdf as the rest of the box, so this is the one case where using a lot of screws is better, they do help hold that plexi.

 

[SirSteve 10+ year member]

Originally posted by evo2k3 is the plexi just one peice being screwed into mdf? if thats the case you use the same screws as you did everywhere else (mabey longer since the plexi is a little thicker. the holes through the plexi should be clear holes anyways and then just use your regular counter sink bit to counter sink them, pilot through the mdf and run your screws in....your not about to acheive as good of a bond between plexi and mdf as the rest of the box, so this is the one case where using a lot of screws is better, they do help hold that plexi.

Yes, attached to the MDF. The plexi maker said drywall screws will not be good as they have an angled head so he recommended sheet metal screws with a flat head. I am having him drill the holes for me, every 3 inches. Is that enough?

 

[evo2k3 10+ year member]

yes--3 inches is about what i did as well.....I think if you were not counter sinking them, he would be right in that you want a flat head, however, since you are countersinking them (like you should) the bevel on the head is going to pull down into the beleved countersink, pulling the plexi down very well. I know a lot of people who dont countersink and use drywall screws have trouble with it cracking.....counter sinking fixed the problem for me.

 

[SirSteve 10+ year member]

Cool. I found a local shop that is doing it for what I think is a really good price. $50 for the plexi and $20 to drill it out for me. I'll post pictures soon!

 

[ss3079 5,000+ posts]

Thats a good price...make sure he does not drill the holes too close together(3" should be fine, because it's 3/4" thick), or too close to the edge of the plexi...as it will crack on you.

- Steve

 

[SirSteve 10+ year member]

Thanks for all the replies!

 

[Matador 10+ year member]

what do you guys mean by counter sinking?

 

[Gauntlet 5,000+ posts]

what do you guys mean by counter sinking?

It's used when youre using screws with an angle head. A counter-sinking bit puts a little indent into the plexi (or whatever surface you'e using) thats about the size of the angled head. The screw can then mount flush with the surface, and it helps to pull the material down to whatever it's being attached to and make a more secure connection

 

[ss3079 5,000+ posts]

Originally posted by Gauntlet It's used when youre using screws with an angle head. A counter-sinking bit puts a little indent into the plexi (or whatever surface you'e using) thats about the size of the angled head. The screw can then mount flush with the surface, and it helps to pull the material down to whatever it's being attached to and make a more secure connection

And it looks better On MDF boxes, it's easier to carpet after.

- Steve

 

[Gauntlet 5,000+ posts]

And it looks better

Definitely....it's suprising how much better it looks compared to not using counter-sinking.