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Can you cut glass with a hacksaw blade ? Answered

For example: opening of 4 feet fluroscent tubes.




8 years ago


Succinct and to the point.

And I don't care what wiki says, mercury is mercury. Since it's been identified, the threat should be respected. Those EPA suggestion are for inadvertent breakage, not purposeful ignorance of the concern.

Mercury has a short half life in the body. Breaking an occasional tube isn't going to be a problem.  I think the half life is a couple of weeks, and we are talking milligrams of mercury per tube. Even the EPA say the glass is more of a hazard.

That said, I can't think of anything useful from thin wall sodaglass tube like that !


Nope, its excreted fairly rapidly. It IS poisonous if you reach the limit, but metallic mercury has a half life of about 2 weeks, compounds a bit more.

I still consider it a problem, even if the broken glass is a larger immediate problem. Consider that it will likely take several bulbs to get that intact 4 ft section of tubing (especially since the author wanted to use a hacksaw...), and that in advising that method as "ok", others may also decide the cost is insignificant.... The big problem imo is one of precedent and summation


Succinct, but not entirely true... I have used a carbide hacksaw blade to cut through the stem of a glass goblet (show prop - we needed an actor to be able to snap the goblet in her hand without requiring stitches), so technically it is possible to cut glass with a hacksaw.
I doubt that it would work nearly so well with a fluorescent tube, given the fragility of the glass and the whole vacuum thing, and as others have mentioned opening a fluorescent tube is not a great idea by any method.
Not disagreeing with Burf, just quibbling over semantics. Cause that's how I roll.


8 years ago

I'm just wondering why you'd want to do such a thing in the first place.

First point - any mistake with the tubes, and you are looking at clouds of splintered and powdered glass everywhere, so wear tough gloves, goggles and a dust mask.  Seriously.

Second point - there is a small amount of mercury in a fluorescent tube, so work outside, away from children, animals and fish.

Third point - no, a hacksaw it not an appropriate tool for cutting glass.

After taking advice from others here on Instructables, I found that a triangular file was the best way to "cut" glass tubes.  File a notch, slow and gentle, long and shallow, until you cut through to the inside and break the vacuum.  At that point, either the tube will fill with air, or it will shatter into a million pieces.

If the tube survives, carry one filing around the full circumference of the tube until it snaps in two.

Be prepared, though, that a large proportion of your tubes will break and shatter - have a vacuum cleaner and dust-pan and brush to hand.

.  Fantastic advice until the last sentence. Do NOT use a vacuum cleaner.

What would you recommend to pick up the powdered glass?

I have a Dyson, and it does very well on debris like this.

.  See cyberpageman's Wikipedia/EPA quote on Dec 5, 2009. 5:52 AM
.  "wet paper towels"
.  But if a vacuum works for you, I can't argue with success.

do NOT use a vaccume or a broom, there are trace amounts of mecury in the tubes and you will contaminate your vaccume and a broom will spread the contamination. the mecury will off gas witch is toxic. you dont realy want to screw around with that stuff. remove large peices carefully by hand smaller peices with wet paper towles and the real small stuff by using belive it or not tape, is't the best way to pick up the reminants i have used it to pick up mecury in larger amounts.

You do know what "trace" means, don't you?  After the breakage of a fluorescent tube, in an enclosed area, contamination levels are monitored in nanograms.

This is what happens when people abdicate responsibility for their own safety to government committees.

I'm from the generation where you were allowed to hold mercury cupped in your hand, and spills were picked up with a dropper pipette.  As far as I am aware, the only mercury in my body today is in my fillings.

Now, I am required by safety law to evacuate my lab and call in a professional decontamination company if a mercury thermometer gets broken.

For general information, the EPA recommendations for dealing with mercury spills say not to vacuum up liquid mercury.  They do say to vacuum after the breakage of a fluorescent tube, then to bag and dispose of the contents of the vacuum cleaner.

yes i do know what trace means. i learned all about it in my hazmat operations class. a 2006-era 4 ft (122 cm) T-12 fluorescent lamp contains about 12 miligrams of mercury. newer low mecury still have 6 mg.(levels vary with manufactor and bulb type). the Agency for Toxic Substances and Disease Registry (ATSDR) recommends 0.2 μg/m3 level as a safe continual exposure limit for children. As an illustration of the effects of a fluorescent lamp breakage, the release of only 1 mg of Hg vapor (~20% of the Hg inventory in a single fluorescent lamp) into a 500 m room (10 × 10 × 5m) yields 2.0 μg/m3 or ten times the ATSDR-recommended level of 0.2 μg/m3. (study done without ventlation). even with ventalation if mecury or mecury empregnated phosphorus is in you carpet it will continue to give off toxic vapor. the regulations for  fluorescent bulbs are being tightened because reasearch is begining to show that there is more health hazards than orignaly thought. studies show that mercury vapor even at low concentrations in the range 0.7–42 μg/m3 can have negative health effects. now is this person going to bust a bunch of bulbs in the family room spilling the contents of numerous bulbs on the rug. i hope not. but i would rather tell him to excercize caution do this outside put the bulb in a bag incase it breaks and try not to be careless. i dont care if they used to give you bathes in this stuff you really shouldent mess with it to extensively. your body eliminates mecury through urination naturally over time but not before causing dammage. i have worked with the EPA there not god they make mistakes too you realy dont want to be vaccuming up this stuff. i do agree with you on the point that if i happen to break a thermometer i am not heading for the hills but im not going to recommend that people play with hazerdous materials. all im saying is be carefull.

DON'T OPEN THE FLUORESCENT TUBE! It contains mercury.  Plus the tube is under vacuum.  The sudden release of the vacuum can cause the tube to shatter.  The phosphor inside is also dangerous.

See http://en.wikipedia.org/wiki/Fluorescent_lamp

"If a fluorescent lamp is broken, a very small amount of mercury can contaminate the surrounding environment. About 99% of the mercury is typically contained in the phosphor, especially on lamps that are near their end of life.[13] The broken glass is usually considered a greater hazard than the small amount of spilled mercury. The EPA recommends airing out the location of a fluorescent tube break and using wet paper towels to help pick up the broken glass and fine particles. Any glass and used towels should be disposed of in a sealed plastic bag. Vacuum cleaners can cause the particles to become airborne, and should not be used."

The broken glass is usually considered a greater hazard than the small amount of spilled mercury.

 I think the glass is considered a greater hazard because it is contaminated with mercury.  

It is toxic.  http://www.osha.gov/SLTC/mercury/properties_health.html

No, the glass is a greater hazard because it typically shivers into dust which can be inhaled - glass splinters in the lungs can cause major, long-term damage, cutting and/or irritating airways.

There are conflicting claims that inhaled glass dust can trigger silicosis - if this is true, silicosis is an irreversibly-fatal degenerative condition. However, the majority of the calm discussion holds that silicosis is unlikely.

drill in from the end first  through the cap ---->    [=================]
that will release the vacume i recomend placing the tube inside a trash bag first incase it breaks it will be contained a little better. then cut using a triangle file like kiteman said. any thing that comes out of the tube needs to be disposed of properly. do not use the tube for holding any thing that you are planning to eat drink or slather onto your self. i dont realy recommend doing this pls be carefull.

A Dremel would do the job.

No! You'll break them. You might be able to cut the ends off with a glass-cutter though.