How close to the edge can you cut 3/16" glass?

[RobertoVespucci]

Seems the smallest bulkhead hole diameter I can find is 1.125". I need two, but a third would be a nice back up drain. How close to a silicone joint or the other holes is 'safe' to try and cut? I have a dremel like tool I plan to use with diamond bits.

 

[Anonymous]

Three issues if you cut too close.

1, it will break when you cut
2, it will crack when you tighten the bulkhead
3, it will break when you accidentially tug on the hose attached to the bulkhead.

I would never cut any closer than 1 inch, depends on the glass thickness. For thinner glass, I will not do any closer than 1.5 inch. Good luck.

 

[RobertoVespucci]

Nice. That should be perfect then, thanks.

Tonight I'm going to get some bits and practice glass. Order the bulkheads, too, I guess.


Have you ever tried reinforcing the glass with a thinnish sheet of acrylic? Worth the effort?

 

[Anonymous]

have you looked at home depot or lowes? You can some up with some bulkhead type fittings by using various pvc parts. Just an idea.

 

[RobertoVespucci]

Actually, I was going to look for true bulkhead fittings while there getting practice glass. But, I would think that a male threaded/female slide couplng with a shoulder for a washer and a matching female threaded/male slide for the inside would work, wouldn't it?

 

[Anonymous]

I don't know about you space requirment, but I think if you take a look at male reducing fittings and bushings you may find something that works.

One problem is the threads are pipe threads and often do not screw in more that 1/4" or so.

I have use slip fittings on a filter I am working on. but once you get those glued up the can't be "unscrewed". So if you have to take it apart later you are the one screwed. :lol:

 

[Rikko]

An old engineer's rule of thumb I've seen repeated a couple times says that you should generally stay at least 1.5 times the radius of the hole you plan to drill from any edge. (Ie. the outside edge of the hole is 1.5x radius, not the center point)

 

[Anonymous]

the rule of thumb is very common but actually is for a bolt loaded so that it is "pushing" toward the edge. Which should not be the case here.Still it would be wise to have some material so you can cut the hole in this case.