Custom build of a very unique assembly table with a glass top.

[sroxberg]

I have acquired a 76" by 34" 1/2" thick plate glass sheet of glass that if just about bullet proof.

I want to build a work surface assembly table that will have multiple functions.

I own lots of Festool tools and that collection includes the track saws, dominos, Vac-Sys, routers etc.

The glass  surface is dead flat so will serve as a torsion box for assembly. The glass top will also serve as a great surface for the Sys-Vac heads to grab on to while using them for various tasks.

I want to be able to also use the table as a cutting surface so want a way to place a 4x8 piece of 2" foam on it when cutting down sheet goods.

I want to also have a top that can be added to if for a large MFT and will make the top from MDF and the Parf Jig.

I'm getting ready to sketch this out in Sketchup.

Any thoughts from the crew at Festoolownersgroup on things to consider like under surface Systainer storage, how to incorporate the vacuum and boom arm, way to have the MFT and Foam tops be easy to mount and remove, and store?

Just starting to dream about how to put this together and value the opinions of this group.

What do you suggest?

 

[Packard]

I have used a 48” x 48” x 1/4” glass top to my picture framing work table.  The main plus was that it enabled exceedingly clean cuts with a utility knife on paper and cardboard.  It quickly dulled the blades, so I used break-off blades, and revealed a new blade after each use. 

But note, I never used it for any impact forces.  In the wood shop I would consider this a risky material to use.  If all you use are rubber or leather mallets, then perhaps OK.  And while I have rubber, leather and resin mallets and hammers, they are infrequently used.  The steel head hammers get most of the use. 

I used the glass top multiple times daily when I had the frame shop and I retired it to my basement picture framing zone.  I still use it, primarily to trim paper.  I have carpet topped cabinets for everything else in that area. 

That glass top is probably too large to integrate in most shops, if you intend to use it where it will not be subject to impacts.  Cutting it down to a more useful size might be a way to make use of this.

I’ve never cut 1/2” thick glass.  I would do some research before attempting that.

And note:  This glass is “bullet proof” until it isn’t.  There will be no warning that you are approaching the bullet-proof-limit.  In one second you are looking at a large piece of glass, and then the next moment is it a shattered mess.  No warning signs that you are approaching that limit.  It just happens.

If this is tempered glass, the edges are particularly susceptible to impact damage. 

 

[woodbutcherbower]

If this is tempered glass, the edges are particularly susceptible to impact damage.

Just to add to the points made by [member=74278]Packard[/member] - you can't cut tempered glass. See below for an explanation why. And any knocks to the edge (even on half-inch thick material) will likely result in instant, catastrophic failure. For those who don't know - tempered glass is used in applications where serious risk of injury is possible due to the regular type breakage into large, jagged, razor-sharp shards. It's used in windshields, shower screens, windows, doors, and a multitude of other applications where this risk exists.

It's manufactured by firstly cutting the glass to size, shaping it as necessary for templated applications, and drilling any necessary holes in it (door handles for shower screens etc). The prepared glass is then placed in a furnace and heated to within a few degrees of its melting temperature. It's then taken out of the furnace and immediately blasted with ice-cold air, which causes the outer skin to shrink very rapidly, compressing the internal mass of the material. The interior of the glass remains under this substantial tension and pressure for the lifetime of the material. When it's subjected to enough impact damage (or even an apparently insignificant scratch), the outer skin breaks, causing the inner material to 'explode' outwards as the tension is released. This results in the glass shattering into hundreds/thousands of tiny cubes which present very little injury potential.

[member=1049]sroxberg[/member] I'd be very, very careful, especially if the glass isn't tempered - and don't ever drop anything on it I also agree that it's a risky material to contemplate using in a shop environment, but that's your call. How to tell? In the UK, every piece of tempered glass, no matter how small, is identified with something called a 'BS6206 kitemark' - a small logo, usually etched or sandblasted onto the surface in one corner, or sometimes along the edge of thicker material. I don't know if US code requires this type of indentification. But at the very least, I'd suggest building some kind of frame or tray (with suitable edge protection) to ensure that it's evenly supported across its entire surface, and that the glass is mounted on some kind of compliant material such as small self-adhesive rubber pads. I say this because half-inch glass doesn't bend. At all.

Don't ask me how I know.

 

[Packard]

In the 1970s, when fuel economy suddenly became a goal of car makers, they looked at ways to reduce the weight of cars.

One of the first things they did, was replace real laminated safety glass with tempered glass.  Laminated safety glass is much thicker and heavier. 

The problem that arose was that the electrical heating elements embedded in the glass to defrost ice and snow, was causing the glass to shatter.  It certainly has its origins on the thinner glass and the tempering process, though I cannot intuit the actual underlying cause of the glass’ failures.

The solution was the change the name of the feature from “defroster” to “defogger”, reduce the current through the heating elements and add a timer so that it will shut off before damage happens . 

…………….

Back in the 1960s, my brother was mowing our front yard with a rotary mower.  It kicked up a small pebble which struck the rear side glass on my dad’s Chevy Blazer.  My brother and I watched as the tiny hole grew into a maze of pebbles. 

Happily, the tiny pieces were perfectly safe to sweep up.  I think if you stepped on the glass bits barefoot, you could probably get a cut, but short of that, it was safe to handle.  We cleaned up, but Dad was not happy.  [eek]

 

[sroxberg]

Thanks for the input and warnings, that is why I came to this group.

I will try to find any markings on the glass, the edges do appear to have a green hue to them if that is a hint.

 

[Packard]

The green appearance on the edges is the iron in the glass.  High clarity glass has a light blue appearing edge.

The color would not be any indication of the heat treating (tempering) of the glass.

 

[rst]

While it is possible that this glass is not tempered, Cutting glass this thick will prove pretty much impossible.  3/8 is the thickest glass to manually cut and that is really difficult. heavier glass is scored, hydraulic or air pressure  clamped and a wood faced rod is usually air actuated to raise from below to snap the glass.  In my 43 years as a commercial glazier, I’ve cut 3/8 and it was a PITA.  Good luck with whatever you decide

 

[Packard]

The glass top might be fine for glue-ups.  You’d have to be careful with the clamps, but there is generally no hammering in glue-ups, and the glass is easily scraped free of any spilled glue.

You could also use it for a sanding station.  Again, easy clean up.  And you could rubber cement sheets of sand paper to the glass if you needed to obtain a perfectly flat surface. 

You could cover a portion of the glass with a sheet of 1/2” thick mdf, either as is or with tightly woven carpet on top of it.  It would protect that part from impact.  It would allow you to dedicate a portion of that top to glue ups and the rest for other work.  It is not the same as being able to cut it down to size, but it could effectively reduce the size of the glass area.

 

[rst]

Just a note, not all tempered units will be stamped as such.  Units used in doors, sidelites, transums or within 18” to the floor are required to be stamped.  Other uses may not be stamped

 

[Svar]

Glass is a poor choice for a work table other than light crafts. Tempered or not either have it's own serious drawbacks. I wouldn't have circular saw or router nowhere near it.
You mention it's dead flat. Have you actually measured that? Tempered glass plates/sheets are often bowed up to a mm per meter, or have uneven thickness. Float glass is flat, but it doesn't come in large thick pieces.

 

[Svar]

...but there is generally no hammering in glue-ups...

Could be just me but there is a lot of hammering, swearing, and kicking in glue-ups.

 

[Packard]

...but there is generally no hammering in glue-ups...

Could be just me but there is a lot of hammering, swearing, and kicking in glue-ups.

I dry-fit first.  I rely on clamps to squeeze the pieces together during glue-up.  The hydraulic pressure build up due to the glue is the main reason for substantial squeeze pressure in the final glue up. 

Some glue-ups are substantially rushed.  I did a four panel screen door and there were 8 joints to be glued and a solid panel to be installed, all to be done within 10 minutes.  Time was the biggest issue.  No pounding required.

 

[luvmytoolz]

...but there is generally no hammering in glue-ups...

Could be just me but there is a lot of hammering, swearing, and kicking in glue-ups.

You're not aloe there, and the cursing is directly proportional to the number of Dominos!