# cutting cutting boards for molds



## westend1530 (Mar 26, 2015)

I picked up a plastic cutting board  to make up some molds.  I cut one edge with my table saw and the edge was very raggedy. What is the best way to cut these boards or clean up the edge. 

I guess I could rout the edge back down 

Thanks for you help 

Steve


----------



## wouldentu2? (Mar 26, 2015)

I have cut this on my table saw with a rip blade and it came out with good edges, a  hand plane will smooth your edges nicely


----------



## Dan Masshardt (Mar 26, 2015)

How old is your blade?  What kind of blade?


----------



## TimS124 (Mar 26, 2015)

You might have a different plastic...one that's more rigid/brittle...a picture of the material might help.


----------



## jttheclockman (Mar 26, 2015)

westend1530 said:


> I picked up a plastic cutting board  to make up some molds.  I cut one edge with my table saw and the edge was very raggedy. What is the best way to cut these boards or clean up the edge.
> 
> I guess I could rout the edge back down
> 
> ...



AS always proper blade for the job works wonders. What blade did you cut them with???  Did you use a zero clearance plate??  Is the blade sharp???  Is the blade carbide???

By the way welcome to the site. I see this is your very first post.:beer::good:


----------



## MesquiteMan (Mar 26, 2015)

Sounds to me like you used the wrong kind of plastic as TimS124 mentioned.  You want the board that you can fairly easily scratch with your fingernail.  If it is hard to scratch, it is most likely nylon or something other than HDPE and will most likely not work.  Not because of the ragged edge but because the resin will bond to it.  As suggested, post a picture and we can say for sure.


----------



## westend1530 (Mar 27, 2015)

Thanks everyone for your help

The blade is a fairly new 200 teeth blade, used for wood, plastic, and laminate. I have been using it quite a bit lately but on wood it's giving me a pretty good clean cut.  I don't think it's dull yet


----------



## monophoto (Mar 27, 2015)

My experience in cutting both plexiglass and HDPE is that you can expect the edges to be a bit rough, even if using a good carbide blade.

The blade will cut (and by the way - as it cuts, it will throw a constant stream of hard bits of plastic in your face.  Safety glasses are essential!).  But the friction of the blade rubbing against the plastic causes it to also melt, at least on edge of the cut.  So its not unusual to see the edge that the blade moves away from left a bit rough.

The rough bits can easily be removed with a gloved hand (you can do it bare handed but it hurts - DAMHIKT), coarse sandpaper or a file.


----------



## low_48 (Mar 27, 2015)

Use a carbide tipped blade. You have to get rid of the chips and not build heat. 200 teeth will have too much friction. Your blade may cut plastic, but not that thick.


----------



## jttheclockman (Mar 27, 2015)

Boy I hit  every point in my first post.    Not know much about you being this is your second post here, we do not know what tools you have available or your experience. but that blade you are using is a steel blade used for cutting plywood such as paneling not regular plywood. It can be used but will dull very quickly because of the glue in plywood. plywood also has grains running both directions and that too will dull it quickly. That is why they make different blades for ripping with the grain and crosscut when cutting cross grain. You can cut plastics with it but again thin plexiglass, not the HDPE you are cutting. Now if you are cutting hardwoods or even pine you will start burning the wood in the cut. Too many teeth left in the cut and that causes heat. That is why it is a thin material blade. Can you cut with it, sure you did. But you are dulling that blade quickly. 

Carbide is the way to go. Now which blade to buy. This presents a problem because not knowing what you do with your table saw besides cutting molds I do not know. If you want a versatile blade  I suggest a carbide combination blade 50 tooth. It will do what you want. It will not give a pefect clean no teeth mark cut but you do not need that for making molds. You can always hit the edge on a disc sander if you have one. The zero clearance plate is always a good idea because it supports the fibers on both sides of the material when cutting and provides a cleaner cut. That material will produce alot of strings and small shards so be careful and wear safety glasses. If you are cutting a lot of it it will also leave a residue on the blade that you should clean off after with a good blade cleaner. It will preserve the blade longer too. 

Now there are a ton of sites and articles on the web that will show what blades to use and how to choose them. here are a couple that maybe helpful


----------



## MesquiteMan (Mar 28, 2015)

Yep, right plastic, wrong blade as already mentioned above.


----------



## Joey-Nieves (Mar 31, 2015)

I use a 10" 98 tooth carbide Amana blade cuts most everything nice and clean.


----------

