What blade to use to cut brittle acrylics on the band saw

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randyrls

randyrls

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I am working on some Inlace Acrylester Galaxy style blanks. These seem to be extremely brittle. I split a blank while cutting it in half on my table saw. The cold temperatures may have contributed to the split. I was able to salvage the blank by sanding off the split parts. But I am not looking forward to drill the blanks. I usually drill short and cut off the blank ends, but may decide to sand off the ends instead.

Can anyone suggest a blade for my bandsaw? I saw a Timber Wolf 1/2" x 14RK that I may get. I will not be using this for curves of course.
 
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I cut LOTS of plastics on my bandsaw.

You are absolutely correct---twice!!
1) Inlace acrylester is brittle--the most brittle plastic I have turned, I believe.
2) TEMPERATURE IS IMPORTANT!!! Do NOT attempt to cut COLD polyresin.

I use a one-half inch wide blade---3 to 14 teeth. The cut is "prettier" with more teeth. The blade lasts longer with fewer teeth. (I surmise the plastic heats up and fills in between the teeth, the farther apart they are, the longer it takes to become "dull")
 
Hmm; I checked and a metal bandsaw blade for my wood band saw is $40. I have a metal bandsaw, so I may try to cut the blanks on the metal band saw. I'm concerned about contaminating the blank with metal swarf. It is too bad they are soooo brittle, because these blanks are very pretty.

Maybe I will just put them away until summer.

Thanks Ed and John!
 
ed4copies said:
How wide is the blade (does it cut straight for 6-10")?
Click to expand...

Ed, just saw your question. It is a 1/2" blade and not sure what you are asking about cutting straight??? It cuts true and straight for as long as the material you feed into it. I use a straight faced fence. No problem. I just cut up some truestone on it to make a pen blank this weekend. Then again I have a Delta 14" bandsaw and is pretty well tuned. I do a ton of resawing on the saw but for that I use a carbide blade.
 
randyrls said:
Hmm; I checked and a metal bandsaw blade for my wood band saw is $40. I have a metal bandsaw, so I may try to cut the blanks on the metal band saw. I'm concerned about contaminating the blank with metal swarf. It is too bad they are soooo brittle, because these blanks are very pretty.

Maybe I will just put them away until summer.

Thanks Ed and John!
Click to expand...


What are you cutting??? Are you just cutting to length for the tubes??? Do you have scrollsaw??? You can always use a very fine blade on this or even a Jewlers metal cutting blade on a scrollsaw.
 
jttheclockman said:
ed4copies said:
How wide is the blade (does it cut straight for 6-10")?
Click to expand...

Ed, just saw your question. It is a 1/2" blade and not sure what you are asking about cutting straight??? It cuts true and straight for as long as the material you feed into it. I use a straight faced fence. No problem. I just cut up some truestone on it to make a pen blank this weekend. Then again I have a Delta 14" bandsaw and is pretty well tuned. I do a ton of resawing on the saw but for that I use a carbide blade.
Click to expand...

That is EXACTLY what I was asking JT. As my existing blades get "dull" (or the gullets fill with plastic), the cut starts to angle slightly. On a 10" pen blank, it is too much!! Actually, even on 5", it is not a good "feature"!!

I'll try the metal blade idea---always willing to experiment!!

Thanks again!!
Ed
 
You guys discussing the metal blade: I tried it, but when all you do is cut wood and plastic, the metal blade clogs up too fast. If you cut metal in between every couple of blanks it's probably not as big a deal.

I believe wood cutting blades with 3-8 teeth per inch works best. The thicker the material, the fewer teeth per inch you want. This is because you don't want the gullet (area between the teeth) to fill up as the blade passes from the top of the material being cut to the bottom, where it can finally expel the material. If the gullet fills up, then excess heat builds up, the material sticks and doesn't fall out properly and you generally just go from bad to worse after that. :crying:
 
randyrls said:
I am working on some Inlace Acrylester Galaxy style blanks. These seem to be extremely brittle. I split a blank while cutting it in half on my table saw. The cold temperatures may have contributed to the split. I was able to salvage the blank by sanding off the split parts. But I am not looking forward to drill the blanks. I usually drill short and cut off the blank ends, but may decide to sand off the ends instead.

Can anyone suggest a blade for my bandsaw? I saw a Timber Wolf 1/2" x 14RK that I may get. I will not be using this for curves of course.
Click to expand...

I turn a lot of Inlace Acrylester and get along well with it. But I was blessed to have Ryan at Woodturningz personally show my how it does it with a skew and from there I was able to develop my own style that works for me and my equipment. *BUT* turning or cutting cold only aggravates the brittle nature of this material.

How many teeth are on your table saw blade? I wouldn't think of using my table saw for blanks with any blade that doesn't have at least 45-50 teeth on it (for a 10 inch blade), and more wouldn't hurt, like a 100 tooth plywood blade. Just as they cut the plywood smoother with less tearing, the same is going to apply to brittle acrylic.

A bandsaw is preferred if you have one, and as I just mentioned above the number of teeth should vary depending on how of a blank you're cutting. 6-8 tpi is probably good for a standard 3/4 - 1 inch square blank, but if your cutting a 2 inch thick piece I'd go for a 3-4 tpi blade. And of course the deeper blades are going to assist in cutting straighter over the thinner blades.
 
ed4copies said:
jttheclockman said:
ed4copies said:
How wide is the blade (does it cut straight for 6-10")?
Click to expand...

Ed, just saw your question. It is a 1/2" blade and not sure what you are asking about cutting straight??? It cuts true and straight for as long as the material you feed into it. I use a straight faced fence. No problem. I just cut up some truestone on it to make a pen blank this weekend. Then again I have a Delta 14" bandsaw and is pretty well tuned. I do a ton of resawing on the saw but for that I use a carbide blade.
Click to expand...

That is EXACTLY what I was asking JT. As my existing blades get "dull" (or the gullets fill with plastic), the cut starts to angle slightly. On a 10" pen blank, it is too much!! Actually, even on 5", it is not a good "feature"!!

I'll try the metal blade idea---always willing to experiment!!

Thanks again!!
Ed
Click to expand...


Ed

Tonight I cut lengthwise 20--- 5" acrylic blanks for some segmenting I am planning. No buildup on the teeth and cut straight and true. Be careful those blades are very sharp. Would not want to get cut by those teeth:eek:
 
Try lubricating the blade before the cut. A candle touched to both sides of the blade while the saw is running should do the trick.
 
Curly said:
Try lubricating the blade before the cut. A candle touched to both sides of the blade while the saw is running should do the trick.
Click to expand...

Be cautious if trying this. the wax can melt into the material and weaken glue joints. It works well when cutting metal, the wax lubricates the blade and doesn't gum up and gather swarf
 
76winger said:
I turn a lot of Inlace Acrylester and get along well with it. But I was blessed to have Ryan at Woodturningz personally show my how it does it with a skew and from there I was able to develop my own style that works for me and my equipment. *BUT* turning or cutting cold only aggravates the brittle nature of this material.
Click to expand...

Maybe I will see if Ryan can give me some suggestions. I believe I got them from there. I got a set of all four of the colors some time ago.


How many teeth are on your table saw blade? I wouldn't think of using my table saw for blanks with any blade that doesn't have at least 45-50 teeth on it (for a 10 inch blade), and more wouldn't hurt, like a 100 tooth plywood blade. Just as they cut the plywood smoother with less tearing, the same is going to apply to brittle acrylic.
Click to expand...

I am using a 40 tooth combo blade on the Table Saw (not SS). It is very sharp but I have some blades with higher tooth counts.

A bandsaw is preferred if you have one, and as I just mentioned above the number of teeth should vary depending on how of a blank you're cutting. 6-8 tpi is probably good for a standard 3/4 - 1 inch square blank, but if your cutting a 2 inch thick piece I'd go for a 3-4 tpi blade. And of course the deeper blades are going to assist in cutting straighter over the thinner blades.
Click to expand...

I ordered that 1/2" x 14TPI band saw blade. I want a smooth cut and speed isn't an issue. I am using a Shopsmith band saw, so I have variable speed. I just modified the saw with a split back bearing to improve tracking and thuned it up as well.

Thanks for all the ideas.
 
As a close to this thread; I cobbled together a small cutting fence that fits on my band saw. With a 1/4" 10 TPI blade I was able to cut the Inlace Acrylester "DIAMOND SERIES" easily and didn't split the material even a little bit.

Thanks for all the ideas and suggestions!
 
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