tube cutting in the flame

[szglassy]

I am needing to cut some 44mm x 5mm tube into 1 1/4 inch lengths.

I do not have a cut off machine and know there is a technique for cutting tube in the flame.

Please correct me if I'm wrong but, do you put a score on the tube, then put a drop of water on the score, then tutch it with a hot 8mm rod?

I am short on the glass and do not have alot of room to experiment.

Thanks in advance!

Sue

[szglassy]

bump

[beachglass]

ya you can do what you said, sue. make your score maybe an inch or so long, and try and get it nice and straight and pretty deep...then put some water on the score and touch with the hot rod. wait until the rod is orange (not white hot) or it will stick to the tube....learned that the hard way lol

just hold it there and after a couple seconds you will see the crack go all the way around following the scores lead

keep in mind that the end of the tube where you have cut it off like this will have quite a bit of stress in it, so dont just ram it in the flame....get it warm slowly

[beachglass]

btw if you go to the glass supplies for sale section, there is a thread called 'new tool' or something like that. they are these things called jaws that really help if you are trying to score small sections of tube, you might want to check them out...it would be pretty hard to do 1 1/4" with a regular knife

[mer]

if it's a one time deal you should probably do the hot rod method, just plan to do more than you need if they have to be perfect because they don't all break *exactly* straight. if you have to do this often i would just pick up an inexpensive tile saw (under $50).

also, who bumps a thread up after one minute?:puzzled:

[szglassy]

Thats great.

About getting it the cut straight-- any advise?

I'm going to check out that tool.

Where can I get a saw for under $50? I know that the tile saws from HD w/ a diamond blade used to make straight cuts is extremely messy and glass dust flies all over the place. Does this saw or tool make neat straigt cuts?

[szglassy]

about bumping the thread-- I really do not know what that means and I had to edit something and thought that I had to type something in order to post.

I'm pretty green, in more ways than one!

[mer]

lol, people usuall bump a thread when it's old enough to get buried under other threads where it won't be seen. it's like pulling a piece of paper back up to the top of the pile. it's all good, this was my first forum too :) .

if they have a harbor freight in you town that's the cheapest place for tile saws. if you don't have one local they're online too, here's one (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3733). tile saws run water over the blade to keep the dust down but they are kinda messy. i use mine with an apron and safety glasses or a face mask outside.

as for straight fire cracks, i'd say do your best to make the score straight and cross your fingers. i really have only about one in five come off crooked and its only by a couple degrees.

[szglassy]

Do you use this to cut tube? Even if it is a 44mm and heavy wall 5mm?
That would be really great if you could make a smooth straight cut with that.

I know with my HD tile saw and the blade that I bought from North Jersey Diamond works, (My tube cutter moved) he had to cut half way through, then turn the glas and cut the rest of the way. It was messy, took forever , and used a special tool to keep the 1 1/4 cut tube tight against the blade.

I was hoping for an easier way, as I am more skilled in the flame than on the cutting machine.

SO-- back to my question---do you think that saw would work with heavy wall????

Flame cut with a couple degrees is not an issue for me.

[Mecha]

If you get a quality tile saw, you can order a nice diamond blade from a supplier like wale. I have a very high end tile saw with a 220 diamond wheel on it and it cuts perfectly smooth. The setup was just under $1000, but that is much cheaper than the $3000 plus for a nice pistorious.

I think you can put a decent diamond blade on even the cheesy tile saws. You will get a much better cut than you will with the crappy blade that comes with it. Just don't push the cut through too fast. Go slow and let the blade do the work.

[mer]

word, you don't need a jig and all that. a special blade makes the cut cleaner but i cut 44 all the time on mine with the original blade (i have a prodo line that requires 8" sections that i can't break off by hand). i just mark it and put it into the blade and roll it with my hands to get the cut all the way through. the part you've already cut keeps the line cutting straight as you roll. whatever roughness is left from the blade can be fire polished out easily.

[Mike_Aurelius]

I had a triangular piece of carbide in my old studio and some blocks drilled into the bench. When I had to cut lengths for my customers, I'd set the blocks what ever distance from the upper edge of the carbide, hold the tube (or rod) against the end block and rotate with "down" pressure over the carbide.

Makes a nice clean score, and once you have that all the way around the tube, the crack becomes nice and clean. If you are doing a lot of these, get a plumbers torch with the soldering iron tip, the tip will be plenty hot and stay that way, just put a drop of water on the score and touch the soldering iron tip to it -- snap crack bingo...

[szglassy]

Do you use the blade that comes with it?

Are the edges fairly smooth? I know with mine that all I need to do is fire polish them.10721

[szglassy]

I just tried to make cut with the flame.

What am I doing wrong?

1. put a score about 1 inch in length on the tube. How deep of a score?

2. using a wet paper towel--drop some water on the score.

3. using a 9mm rod-- heat the end until orange-but not white.

4. touch the rod on to the wet score

4 now it is supposed to split all the way around the rod and break off fairly evenly.

that's what I did and it did not score or break around the rod.

Any suggestions?? Thanks, Sue

[Mike_Aurelius]

The score should physically break the surface of the glass -- not a light scratch, but deep enough that you can feel it with your finger nail.

I'd go longer, at least 1/3 of the way around the tube.

[szglassy]

wow--all I have is a score knife--do you think that I should purchase one of those large tube scoring tools?

Your technique about the plumbers torch sounds great, but I only need to do a few pieces.

[Mecha]

Also, be sure to hold the hot glass rod against it long enough. Sometimes it can take a few seconds. As long as the score is straight and deep enough, even a short one should start a running crack no prob. I have seen 12 in diameter tubing cut clean around with just a two inch score.

[Mike_Aurelius]

You probably need more leverage -- is there any way to clamp the knife down on the table then force the tube against the cutter?

When we first started cutting all we had was a sheet glass cutter, so what we did was put a couple of saw kerfs in a piece of wood and tapped the cutter into that so that only the carbide rolling cutter was sticking out.

You do need to really break through the surface, and I suspect that may be why it isn't breaking properly.

[Mr. Wonka]

You can save yourself lots of time and money by getting these cutters (http://www.thegldg.com/forum/showthread.php?t=15770&page=3)... they are outstanding!

[brettodie]

1 inch score nice and deep. use a smaller rod, i like 5 mill.
seems to travel around easier if use the hot rod closer to one end of the score then the other,could just be a perception thing.
if you do alot of these go the harbor frieght route and get a cheap saw and add a nice blade to it. peace brett

[szglassy]

wow-- those cutters look great.

has anyone used them on 44x5 rod cut into 1 inch sections?

[szglassy]

Thanks everyone you have all been a great help!

I'm going to order the " new tool" cutter.

[mer]

if you get a score all the way around you can break it off perfect using the technique in this vid (http://www.thegldg.com/forum/showthread.php?t=16928).

there's some talk later in the thread as to how one would go about doing this yourself.

[Roger K]

I'm curious. What do you do with these sections of tube?

[bc]

fire polish an there practice tubes for anal sex.....

[Swampy]

Oh you just had to go there didn't you... :-)

[BlueBeard]

try scoring it and putting water on there like everyone else is saying but dont use a hot rod just get a nice hot pinpoint flame and just barely touch it to the score and wait a couple of secs. if it doesnt break on its own have a spray bottle of windex or water and just spray it while its still hot and that should do the trick. i work in a scientific shop and i crack glass like this all the time. on a lathe you score the whole way around the tube and follow the same process. I crack every thing from 100mm to like 300mm heavy wall just like this. one time it took four guys but we cracked a tube that was like 3ft in diameter and like 6ft tall.

[szglassy]

OH MY GOODNESS--for heavens sake please get your mind out of the gutter. I'm only making napkin rings. Plus my customers would not apperciate that type of thing anyway.10751

[szglassy]

BlueBeard--

would doing that make a nice even crack?

would the score need to be fairly deep and about an inch?

wow--a 3ft dia. tube-- what did you make with that?

[BlueBeard]

it should be pretty straight but its no guarantee. we didn't make a damn thing with it we just cracked that length and shipped it out. I cant imagine what we charged for it something ridicules im sure.

[VinE]

check out this thread: http://www.thegldg.com/forum/showthread.php?t=13618&highlight=thermal+shock

[szglassy]

I noticed on the video that the break was done lying flat on the bench.

I was holding the tube with one hand and the hot rod with another.

Maybe keeping it flat on the bench will allow for a straighter and more uniform break?

[beachglass]

the uniformity is determined already by the score i believe, so it should come out the same whether you hold it or not. i just leave on my bench cause its easier

[Swampy]

and if it breaks off I don't have to chase it.