Best way to melt plastic with no burn marks?

[Arachnomore]

Hey guys, I don't know if you remember, but I was going to start making some containers with drop in vents for slings. I have came up with a design that will put me right around the 10 dollar mark each and they are going to look really swell I'm excited. I am finishing up with my last issue and it seems to be a hard one to gather information on. I am looking to cut an 1" to 1-1/4" hole through some .1" thick plastic. What would be the best way to cut these holes without cracking or burning the edges black?

Thanks again,
Isaac

 

[recluse]

A hole saw might work if you dont try to drill too fast and you use it on a high enough RPM.

 

[Moltar]

I'd tape it off with masking tape and use a drill with a sharp bit. Go slow and easy. You could find something to melt it with but it seems to me thare's be so much melted material with a hole that big that it just wouldn't look clean.

 

[Oasis Inverts]

I use a soldering gun.......

 

[Arachnomore]

for 1 1/4" to 1 1/2" holes? There has to be some burning there... I am going to be installing vents so I have about 1/8" each side to allow for some black... I'm leaning more towards a cutting technique, but with .1" material... it cracks easy.

 

[Moltar]

You can buy hole cutters that mount like a drill bit, I shoulda' thought of that before. I think they get that small (not sure tho') They're made for wood but i bet with the same precautions as above you could make it work.

 

[Arachnomore]

think something like this would be able to do the job without cracking it?

http://www.mkmorse.com/IMAGES/mc1.jpg

 

[Moltar]

That's what i had in mind, yeah. Looking at those big teeth now though i have to wonder if it would work... You may have to sacrifice a couple of plastic boxes just to get your procedures down unfortunately. Maybe they make similar bits for glass/plastic. You could also try some sort of dremel grinder....?

 

[Arachnomore]

I was

I was thinking of setting up a dremel and a patternt to follow... but, then I thought I could just set up the lid upside down.. heat up a 1/4" bolt and drop it through.. bolt and washer on the other end... so the lid is tight and no movement.. then slowly start drilling through it... that would reduce the chance of cracking if I had it tight.

 

[kingfarvito]

i dont know if it would work with the hole cutter but when im drilling plexi i just drill in reverse i have yet to have anything crack

 

[Arachnomore]

see you are using probably 1/8" to 1/4" though.. I need 1 1/2" exactly.. I will probably order what I need later tonight... so I need to ask the questions now

 

[Hamburglar]

It might work... just be care with how much pressure you apply. Sometimes cracking can happen when the bit is just about to push through but the plastic gives way first. If you heat the bit a little bit it might soften the plastic making it harder to crack. Not hot enough to burn all the way through .... just a thought... good luck

 

[jbrd]

Well from a machinist point of view, I would use a router myself because A) A router runs at high rpms. B) A router bit has many faceted cutting edges. C) Combine A and B you will get no burns on your acrylic as long as you do not let it sit in one spot too long.
Now just make a jig to hold your acrylic in place and you are in business.

Try McMastercarr or Harbor Freight for inexpensive bits.

 

[Arachnomore]

yea that go flagged ^

The reason is... some people would rather have something else that is press fit flush and crystal clear... when you get those cheap plastic boxes and start drilling holes in them... to me they look bland. .... one cylinder, one vent... thats all. The cylinders are around 4 - 5 bucks after shipping.. and the louvres about a buck a piece... so that plus shipping for 10 bucks.. not bad.

 

[Pulk]

I use a nail heated on a gas stove... shiny/smooth nails leave the black residue, regular ones don't. The difference might be that the good ones aren't galvanized, but I'm not sure if that's the case/proper term.

 

[dianedfisher]

I'd use a drill press and just punch through slowly. I use one to drill out the air holes (from small to very large) for all of my acrylic boxes. Di

 

[Stan Schultz]

... I am looking to cut an 1" to 1-1/4" hole through some .1" thick plastic. What would be the best way to cut these holes without cracking or burning the edges black? ...

Go to your favorite home builder's supply, the plumbing department specifically. Either take along a tape measure or "borrow" one off their shelf. Find a simple, thin walled piece of copper plumbing, maybe a nipple, a short length of pipe, or an "L" with an outside dimension exactly what you want. Buy it. Or, buy several different sizes to experiment with.

Once you're home, using a pair of pliers, heat it in the flame or against the heating element of your kitchen range until it just barely begins to glow. Remove it from the heat and wait two seconds. Then carefully, but with "authority," use it to melt the hole you want where you want it. If the plastic is too thick you can even do it in two stages if you're careful and practice a little.

Forgot to mention that you should do this with all the windows and the door open. Hot plastic raises a terrific stink and might even be carcinogenic. You'll need lots of ventilation.

The hot copper plumbing will not burn the plastic unless you have it glowing hot. It doesn't need to be all that hot.

Also, the side from which the metal enters will develop a small, donut shaped, raised ring around the hole. The other side of the plastic (where the metal exits) will be as smooth as a baby's behind!

Now, about the 'authority' part: This means that you don't waiver, get weak knees, get nervous, or otherwise mess it up. One rather fast-but-not-panicky, fluid motion. Like you knew what you were doing and you meant every word of it!

Be forewarned that you will have to experiment a little at first, so plan on ruining at least one unit.

Enjoy your holey tarantula cages!

 

[moose35]

an easy way. is to go to the home depot. buy a carbide hole saw made for cutting through tile. and drill away.
they have no teeth. only a carbide dust coating. $7.00 and your done



moose

 

[Arachnomore]

an easy way. is to go to the home depot. buy a carbide hole saw made for cutting through tile. and drill away.
they have no teeth. only a carbide dust coating. $7.00 and your done



moose

Thanks for all the replies. This is probably the method I will go at first. I am going to make a system that I can just mount the lid down... take a piece of 1 5/8" ID steel tube and drop hot rings through it so they are spot on. I'm pumped to get going again on this.

 

[Stylopidae]

Soldering iron...a $20 investment which has saved me at least five times that amount.

Just be careful when melting the holes...my bit is bent and I will need to replace mine soon. However, it's saved me at least $100...so even if I screw up with the next one, it's still worth the money to buy one once per year (which you shouldn't have to).