Need an Idea for a 1/8" Hardboard Substitute

[patlaw]

Some of the projects I make are small boxes that house push button switches to control audio equipment. They're nothing fancy in any way. The top are made of 1/8" hardboard. It's a great material to use because it is thin, cheap, easy to drill, and non-conductive. However, I'm finding it difficult to get smooth edges. Of course I understand why it gets fuzzy. I'm afraid I need to change to some sort of plastic. Should I just buy some small sheets at the box stores, or is there another idea for pieces of 1/8" or so machinable plastic? If I by Plexiglas or something similar, how do I polish the cut edges? Sandpaper?

 

[Canuck]

Lexan cuts really nice and clean on the table saw using an 80 tooth Freud plywood/melamine blade. I have purchased sheets of Lexan at HD (only seen it in clear though) and cut it down for picture framing and window sashes with pretty good success.

1/8 Baltic Birch plywood may be an option as well.

Wayne

 

[redknife]

Also, torch heating the Lexan edges smooths them. Could also wet sand.

 

[Mike Davis]

Torch the edge with a very small flame and move quickly, watch as you go and you will get a feel for how fast to move the flame. It is very easy to overdo it when you are first learning.

 

[Hmerkle]

Mike you can also use a buffing wheel and a compound to "polish" the edges.
rouge or any one of the compounds at the big box store.

you need a buffing wheel and a grinder for this of course, so the torch method might be quicker and easier to start...

 

[Ed Fasano]

You can look at phenolic sheet stock. It's comparatively expensive, but is non-conductive, strong, dead flat, stable and machines fairly well. Another material to look at/for is tempered hardboard. It fuzzes a bit less. Moreover, Cannuck's response speaks to the method by which the material (hardboard or otherwise) is cut.
(1) A very good and sharp blade will reduce or perhaps eliminate the fuzzed edges.
(2) Masking tape on the sawn cut lines might improve the cut hardboard edges.
(3) Cleaning up the edges with a pattern-guided router is perhaps another thing to consider.

 

[ehpoole]

Another option is to apply an oil-based clear coat like polyurethane to seal the edges of your hardboard. Spray finishing or a wipe-on finish will work best as you do not want to flood the edges with a lot of finish for the first coat or two or they will swell and you may need to sand the edges smooth again. The first couple light coats will seal everything and prevent further absorption of finish along the edges.

If you apply your lettering prior to sealing the hardboard with a clear coat then the finish will also protect the lettering from wear and tear since such will be underneath a tough and durable finish.

Other options include thin Baltic birch plywood, as used in modeling, as well as Lexan (polycarbonate) and Plexiglass (Acryllic). Acryllic is the stiffer material but can shatter if stressed or dull bits are used (forcefully) or if over flexed whereas Pokycarbonate is much more flexible, not as rigid per given thickness, and is essentially shatterproof (an appropriate thickness is even bulletproof).

My personal preference tends to be aluminum, but if you genuinely need a non-conductive panel then that is not an option (though one could use anodized aluminum). An advantage of metal panels is the ability to properly shield against RFI/EMI emissions or pickup when used with an all metal chassis that is properly grounded or shielded, which can be desirable for high impedance lines that will be subject to high levels of amplification.

 

[Jeff]

It's a great material to use because it is thin, cheap, easy to drill, and non-conductive. However, I'm finding it difficult to get smooth edges. Of course I understand why it gets fuzzy.

No experience to share here but I'm wondering why you want to abandon a tried and true friend and re-invent your learning curve with Lexan? I'm assuming that at one time you were getting smooth edges without fuzziness and life was good. When did that go south and become so objectionable?

Before you throw the baby out with the bathwater take a look at this NCWW thread for a few tips and pointers about hardboard (Masonite).

http://www.ncwoodworker.net/forums/showthread.php?t=33248

1. Maybe Zinsser rattle can shellac on both faces before cutting on the table saw with a good 60-80 tooth blade?

2. A few pics of the problems you're now seeing?

 

[patlaw]

No experience to share here but I'm wondering why you want to abandon a tried and true friend and re-invent your learning curve with Lexan? I'm assuming that at one time you were getting smooth edges without fuzziness and life was good. When did that go south and become so objectionable?

I'm not sure my method has ever been tried and true. All of a sudden, with the last few projects, my joints are fitting much better, and the boxes are even square. The fuzziness is just now becoming objectionable. Plus, we all strive to get better. A new sheet of tempered hardboard has a very smooth, rounded-over edge. That means that smooth edges are possible. As far as Lexan is concerned, I would LOVE to be able to make the boxes completely out of Lexan. You gotta love the way the stuff welds together. Now that I'm learning to measure and cut, I may give that a try, as well. Even if I do, Masonite will still be a good way to prototype a project.

Before you throw the baby out with the bathwater take a look at this NCWW thread for a few tips and pointers about hardboard (Masonite).

http://www.ncwoodworker.net/forums/showthread.php?t=33248

There are some great suggestions there that indicate that I may be able to achieve the outcome I want.

1. Maybe Zinsser rattle can shellac on both faces before cutting on the table saw with a good 60-80 tooth blade?

I don't have a table saw, but my Festool Kapex does have a 60-tooth blade that should be up to the job. I already have some Zinnser shellac, so I'll try that today.

2. A few pics of the problems you're now seeing?

Let me try that. I have to grab the few minutes of daylight that I can to drag out my SCMS and try to get some projects done.

 

[KenOfCary]

Two things come to mind for your application. 1/8" or 1/4" MDF which is not usually carried at the big box stores so would probably need to be ordered or picked up at someplace like the Hardwood Store in Gibsonville. The other things I'd look into using is the High Density Plastic - the white stuff - it comes in various thickness and can be cut on the table saw or band saw and the edges smoothed with sandpaper.

The High Density plastic is also very useful in making jigs where you want a slick surface for the wood being machined to ride on.

 

[patlaw]

Two things come to mind for your application. 1/8" or 1/4" MDF which is not usually carried at the big box stores so would probably need to be ordered or picked up at someplace like the Hardwood Store in Gibsonville. The other things I'd look into using is the High Density Plastic - the white stuff - it comes in various thickness and can be cut on the table saw or band saw and the edges smoothed with sandpaper.

The High Density plastic is also very useful in making jigs where you want a slick surface for the wood being machined to ride on.

When I was working in manufacturing, our mechanical guys used a lot of Delrin. Is that High Density plastic? In any case, where is High Density plastic available? It sounds like a possibility for this application.

 

[nn4jw]

I don't cut Lexan or Acrylic sheet that thin with power tools. Too easy to overheat and mess up the edge. It's also slower than using the proper tool.

http://www.homedepot.com/p/Plastic-Sheet-Cutting-Tool-GE-41/202038073

It works like a glass cutter. You score the line and snap the plastic at the line just like cutting glass. Under $5 for the scoring tool.

A 10"x8"x0.093 Lexan polycarbonate sheet at Home Depot is also less than $5. 0.093" is slightly thinner than 1/8" (0.125) but should work fine for your application. When drilling I suggest a good and sharp brad point drill bit. If I'm looking for a 1/4 hole for switches and pots I usually drill a smaller hole and expand it with a tapered reamer (Ace Hardware - $20). Trying to drill a large hole in plastic often cracks and splinters it by catching.

 

[Pop Golden]

The name of that white stuff is UHMW (ultra-high molecular weight) plastic. Woodcraft & Lee Valley sells it.

Pop

 

[Charlie Buchanan]

Acrylic sheeting comes in various thicknesses and colors. Black, white and other opaque colors . It cuts nicely on a table saw with a clean, sharp blade. You can wet sand the edges. Cut it before peeling off the paper protective covers. I have made several two-sided displays sandwich as well as router bases using 1/4 inch acrylic sheet. There's probably an industrial plastic supplier in Raleigh. We have Triad plastic supply here in WS.

 

[KenOfCary]

When I was working in manufacturing, our mechanical guys used a lot of Delrin. Is that High Density plastic? In any case, where is High Density plastic available? It sounds like a possibility for this application.

Here is a link to a version of it that Rockler sells. It is known as UHMW Plastic.

http://www.rockler.com/uhmw-plastic-jig-stock-3-8-inch-thick

I find it extremely useful for jigs and other uses. It is very dense, cuts well and is very slick for use as runners and other jig usage.

For your application it is very workable - drill, cut shape, just go slow with power tools so as not to melt it. You can even cut it with a Forstner bit.

I'd look for the thickness you need on smile.amazon.com or maybe even ebay. I've seen large quantities available on Craigslist once, but not recently.

This stuff is great for certain applications. Much easier to work with than Lexan or plexiglass for what you're trying to do.

 

[smallboat]

You'll have a tough time bonding UHMW if you go that path figure on mechanical fastners.
its a polyethylene which, like polypropylene is very difficult to glue.
Not impossible but not with the stuff you probably have around the shop.
Otherwise its wonderful stuff.
Great for work surfaces if you are going to be assembling with epoxy

Also keep in mind that acrylic sheet is available in two forms- cast and extruded.
I've had much better luck with cast sheet whether using conventional tools or laser cutting and engraving.

 

[KenOfCary]

Yes, it is tricky to attach to other surfaces. I usually use the Gorilla glue or mostly two part epoxy to fasten it securely. I mostly use fasteners to attach it to other surfaces, which I expect would work fine in your application. It can be drilled and countersunk to allow the screws to be inset with very good result. Not perfect for all applications, but if I understand your situation, it might be a good choice.

 

[John Harris]

Hardwood Store of NC has 5x5 sheets of 1/8 inch Baltic Birch plywood for $25. If you buy 3 or more they is $20 a sheet.
https://hardwoodstore.com/hardwood-plywood

 

[ehpoole]

I don't cut Lexan or Acrylic sheet that thin with power tools. Too easy to overheat and mess up the edge. It's also slower than using the proper tool.

http://www.homedepot.com/p/Plastic-Sheet-Cutting-Tool-GE-41/202038073

It works like a glass cutter. You score the line and snap the plastic at the line just like cutting glass. Under $5 for the scoring tool.

A 10"x8"x0.093 Lexan polycarbonate sheet at Home Depot is also less than $5. 0.093" is slightly thinner than 1/8" (0.125) but should work fine for your application. When drilling I suggest a good and sharp brad point drill bit. If I'm looking for a 1/4 hole for switches and pots I usually drill a smaller hole and expand it with a tapered reamer (Ace Hardware - $20). Trying to drill a large hole in plastic often cracks and splinters it by catching.

For another perspective, while I have used the above knife for plastic sheet goods, I much prefer the tablesaw, bandsaw, router, circular saw, etc. I have never had any issues with overheating Acryllic or Polycarbonate sheets when simply cutting with a relatively fine toothed blade at a reasonable feed rate (such as a blade suitable for crosscuts or plywood) or a router with the speed turned down a bit. For that matter, I also use all of the aforementioned on non-ferrous metals like brass and aluminum for such projects as well and they all do just fine. I also have had no issues using common twist bits, Forstner bits, and hole saws for drilling plastic sheet goods, though brad points are certainly fine to use -- really, whatever you already have should work just fine so long as they are sharp.

The important thing with Acryllic (not so much Polycarbonate as it does not shatter if stressed) is to use sharp tools and bits and consider drilling larger holes in steps to ensure the bit can not catch (it is also good practice to always drill into a backer board to further relieve stress when a drill but breaks through the far side).

If you want to smooth the cut edges of your plastic sheets you can simply pass a torch, relatively quickly, along the edges to briefly liquefy them and they will clean up very nicely. Practice a few times on some scrap to get the hang as to how fast and how close to the flame works best for you. You can also use a torch or heat gun to warm the plastic sheets should you ever wish to bend it into a curved shape for a project (though Lexan/polycarbonate is the better plastic for bending applications as there is no chance of shattering if you bend too hard without adequate heating).

 

[ehpoole]

Lexan cuts really nice and clean on the table saw using an 80 tooth Freud plywood/melamine blade. I have purchased sheets of Lexan at HD (only seen it in clear though) and cut it down for picture framing and window sashes with pretty good success.

1/8 Baltic Birch plywood may be an option as well.

Wayne

It also cuts very nicely using Freud's 60-tooth crosscut/finish tablesaw blades as well if one has such on hand (I tend to use this particular blade for everything except heavy ripping as it is a great general purpose blade and leaves very smooth edges regardless of grain orientation. I have used it for everything from wood, to plywood, to plastics, to brass and aluminum without any issues over the years. I have plenty of other blades to choose from (including 80+ tooth blades), but this has become my primary go-to blade for many jobs since it is usually what is installed.

But any fine toothed tablesaw blade will usually cut plastic sheet goods beautifully when accompanied by an appropriate feed rate (and the feed rate is not especially finicky, you just do not want to go too slowly).