Best saw/blade to cut plexiglass & which glue ?

[LuxLuthor]

I want to make some custom rectangular boxes out of some sheets of black plexiglass I ordered from McMasters. They are 12" square & several thicknesses (3mm, 4.5mm, & 6mm).

Not sure what is the best type of electric saw/blade to neatly cut various size (4" to 7") rectangles and then securely glue into box. Thanks

 

[LukeA]

I want to make some custom rectangular boxes out of some sheets of black plexiglass I ordered from McMasters. They are 12" square & several thicknesses (3mm, 4.5mm, & 6mm).

Not sure what is the best type of electric saw/blade to neatly cut various size (4" to 7") rectangles and then securely glue into box. Thanks

For sawing, you're not going to beat a well-adjusted tablesaw with a carbide-tipped blade. I'd recommend a fine blade for a smoother cut, but with a sharp blade the results will still be good with a little coarser blade.

This has been my experience.

 

[LuxLuthor]

I wonder if anyone has tried one of these hand tools? I guess their idea is score and snap, and it avoids the saw blade melting effect ?

 

[LukeA]

I wonder if anyone has tried one of these hand tools? I guess their idea is score and snap, and it avoids the saw blade melting effect ?

There's no problem with melting using a good powersaw setup. If you sand the cuts with a stationary sander though (won't need to sand tablesaw cuts), be ready with a utility knife to cut off the fuzzy meltings.

Score-and snap might be alright, but I don't know if you'll get perpendicular edges.

 

[Lynx_Arc]

if you have a table saw I would just use it making sure the faces are taped or the covering is still on it that helps with the melting some. You can then sand it if needed. score and snap probably would require sanding also I would think and if not done perfectly could ruin a piece.

 

[gallonoffuel]

I personally do not like the score and snap method, as it is somewhat difficult and very time consuming to get it scored enough to break cleanly.

The only time i cut plexiglass, i used an electric angle grinder with some cutting discs for metal. If you keep it from getting too hot, it wont bind, and the little melted globs will just break off the edge when you're done.

 

[Marlite]

Lux I had a display case made of clear plexiglass at a "Store Fixture Display" and the shop foreman said you retain the protective covering and ensure the Carbide blade has 60 sharp teeth for a smooth cut. I scored a new 8" 60 Carbide blade tooth at an estate yard sale for $6.00. Worked great.

Good Lux

I want to make some custom rectangular boxes out of some sheets of black plexiglass I ordered from McMasters. They are 12" square & several thicknesses (3mm, 4.5mm, & 6mm).

Not sure what is the best type of electric saw/blade to neatly cut various size (4" to 7") rectangles and then securely glue into box. Thanks

 

[mudman cj]

My opinion is sort of a combination of previous posts. The scoring tool will be difficult to use for the thickest piece, but should work for the thinner piece and probably even the middle piece. It requires careful use to keep it against a straight edge, for which a clamped T-square would suffice. Break it over a hard edge and preferable clamp an edge on the top of the pieces as well while breaking. Even then, it still may not break cleanly and could require filing to get a perpendicular edge. The table saw will provide that with greater assurance.

As for the adhesive, I have had good luck using 3M DP460NS two part epoxy, but although it is very strong it is not clear. For a clear solution I would suggest an acrylic adhesive such as IPS Weld-On products (#4 and #40 are used to make aquariums) or similar products such as H-94 manufactured by Shwartz chemical co. or USP SC-125. Be sure to use these in a very well ventilated area.

 

[mahoney]

Score all the way through is better than score and snap, less likely to chip, but neither will leave a clean enough edge to glue well. You'll need to file or sand the edge after. And you will need to be careful to keep the edge straight and square.

The thin plexi glues are just a solvent that melts the plexi together. (as has been mentioned, nasty vapors...no skin contact) For them to work well you need an edge that's fully in contact with the surface you are gluing it too. There are thicker glues, which are basically the solvent with clear acrylic dissolved in it, these will "gap fill" to some extent, but the clear glue line may stand out on your project.

The best cut will be from a "triple chip" grind carbide tipped saw blade on a table saw equipped with a zero clearance insert. Better sawblade makers make blades with this grind for cutting plexi, laminate, and aluminium. Remember, for the best cut, the blade should just barely protrude above the material, so as long as the arbor hole is the right size, you can use a smaller diameter blade on your tablesaw for this job and save a little money. If you have an existing blade that's ready for sharpening anyway, and a good local sharpening shop, you might be able to get them to change the grind to triple chip for a modest upcharge over the regular sharpening cost

 

[Gary123]

I've cut plexiglass numerous times, used a plain old hand hack saw for metal. Works great every time. Scratch a line for your mark.

 

[LuxLuthor]

I was looking at this website which sells various plastic/plexiglass tools, including the cutting type which they use & say works up to .25" which is more than the thicker 6mm sheet I got. They also have those IPS glues.

Here was another type of laminate cutter made by Virutex, but don't know how it would work on my plexiglass.

I don't have a table saw, although I was looking for an excuse to get one, and reading mahoney's post doesn't leave me as optimistic about the score/snap idea.

Basically, I want to make a battery box to hold 4 or 8 of the much lighter & smaller 26700 size A123 cells for a MaxaBeam spotlight. It uses this 5.5 lb NiCad "paper weight" pack that has the anchor slide mount holes on top, so I would need to also drill/dremel/melt those keyholes on one sheet glued to top of box.

I don't need to worry about the corner ear loops, as they are to hook a shoulder strap to carry the light. With A123's you won't need a strap.

 

[Oznog]

The thin plexi glues are just a solvent that melts the plexi together. (as has been mentioned, nasty vapors...no skin contact) For them to work well you need an edge that's fully in contact with the surface you are gluing it too. There are thicker glues, which are basically the solvent with clear acrylic dissolved in it, these will "gap fill" to some extent, but the clear glue line may stand out on your project.

Beat me to it. Use the solvent weld, all the way. Not only is the bond as strong as the acrylic/lexan, but it's optically clear. The seam may not show up at all.

 

[SafetyBob]

Lux, the last time I went to our big plastics place here in Oklahoma City, they cut sheets with a table saw and they told me they used a special plastic cutting blade. 60 tooth makes sense because if you had more teeth they you would really get a nice melting mess on your hands. And I did think they did recommend a 60 tooth blade if I needed to trim stuff up.

While I invite you to purchase a table saw, and I recommend a good Delta Uni-saw (make sure and get the Besmeyer 50" fence) ....it will only mean you will have to get a whole bunch of other garbage and fill up your garage or shop even more. So let's forget the big saw.....

So if you are really worried about the quality of the edge and stuff, have your local plastics guy do the cutting to exact sizes you need and forget it. You can still do this despite already having the stuff from McMasters...... or how about a neighbor with a table saw? Perhaps you bring the blade? That would make the most sense right now.

Now, without breaking the bank, Proxxon makes a table saw for hobby use. Here is the same saw offered by another company. Since it uses 3 inch blades you could either slow the blade down to get a good cut (as recommended by the company) or I think you could get a 3" slit saw (think metalworking) that might work. This is a question for the home shop machinist forum!!

Here is a link to that saw from Micro-Mark:

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=80463

Hope all the rambling helps.


Bob E.

 

[mahoney]

No tablesaw...well...

for the cost of one you could hire someone to make dozens of custom boxes for you. Perhaps somebody like Unibox has one that would work?

http://www.uniboxenclosures.com/

A portable circular saw will work, but your pieces are on the small side for that to be safe. If you can work out a jig to support them and hold them in place while cutting, you could do it safely, and small triple chip blades are available.

It's just a battery box, and if you can live with a thick glue line, use the score method or a handsaw (hacksaw or any other fine toothed blade) to cut the pieces and then use an epoxy for the glue. It'll work OK.

If it has to be pretty, a good quality cut and the solvent glue is the best.

 

[LukeA]

Now, without breaking the bank, Proxxon makes a table saw for hobby use. Here is the same saw offered by another company. Since it uses 3 inch blades you could either slow the blade down to get a good cut (as recommended by the company) or I think you could get a 3" slit saw (think metalworking) that might work. This is a question for the home shop machinist forum!!

Here is a link to that saw from Micro-Mark:

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=80463

Hope all the rambling helps.


Bob E.

I was also thinking about recommending that saw. It is on the expensive side for such a small saw though.

 

[turbodog]

I've cut a pretty good bit of plexi and lexan. I use a hollow ground blade from home depot. No melting.

In case you don't know.... that means the blade is thicker at the outside edge. The inside part of the blade never contacts the material, unless you aren't cutting straight.

The blade is labelled "for plastics".

 

[VegasF6]

They have itty bitty hobby table saws for like 35 bucks, I am sure I have seen them at harbor freight. Also, perhaps you would benefit from a small laminate trim router, or a roto-zip type tool?

 

[LukeA]

They have itty bitty hobby table saws for like 35 bucks, I am sure I have seen them at harbor freight. Also, perhaps you would benefit from a small laminate trim router, or a roto-zip type tool?

Those saws have bearings that won't last through an hour of use.

And good luck to anyone who tries to get a remotely straight cut with a rotozip.

 

[will]

The best way is to cut on a table saw or a radial arm saw. That will give a nice straight edge.

Using a rotozip or a router may give little 'digs' on the edge of the material .

The straighter the edge, the better the contact with the mating piece,

look on line for plexiglass adhesive and use that.

 

[VegasF6]

Actually they make 4" table saws in all quality's including the micro mark saw at well over 400 dollars. Just because it is small doesn't mean it is bad. Also routers are used in arylic and other plastic manufacturing quite often. Carbide bits, plastic cutting bits etc are availible. And straight edges for rotozips.
My logic was A: he isn't looking to spend hundreds of dollars in equipment to make a couple of battery boxes,
B: the rotozip or another laminate trim router of whatever quality could be used for other things. Perhaps cutting circles or trimming a lip to set the lid in or whatever else.

I don't imagine for instance the need to buy a 600 lb left tilting cabinet saw like mine, or a 2 1/4 hp freud router and precision table and bits like mine, or either of my bandsaws or 72" drill press.

I will say that the 3 years I spent in marble manufacturing, fiberglass manufacturing, and acrylic manufacturing, running 10 ft heat vacuum form tables gave me an appreciation for the right tool for the job.

I am sure you will get some excellent suggestion here LuxLuthor and I wish you luck with your endevor.