I am going to be making a fairing for my new roof rack and was wondering what the best method for cutting/shaping it would be? I just got back from Lowes and I bought a 2x4 sheet of .25 thick material.
Cutting acrylic
- Thread starter davegonz
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cut it
We use an old plywood blade on a table saw.
works well. It is kinda dull and mostly melts through the plastic
Sharp blades tend to bite and shatter plastic.
I also use a fine blade on a jig saw. keep the plastic coverage
on the sheeting until after the cuts have been made.
if its to late masking tape will keep the jig saw base from maring the
surface.
Same thing applies to drilling holes for mounting. you want to round
the edges on the drill bit slightly so you get the melting effect
othewise the bit can grab and shatter out your hole.
unfortuneately drilled holes are usually near the edge they end up
blowing out pieces
thats all the wisdom I have for you on the matter good luck
For shaping infared h eat works to soften the plastic
be warned if it isnt warm enough when attempt a bend it will
crystalize on the outer radius and get foggy in the corner and possibly even break.
Another small bit of info that applies. Always heat the plastic from the side that is gonna be the longest radius of a bend..
this little tidbit cost me a buck or two in wasted plastic to learn.
We use an old plywood blade on a table saw.
works well. It is kinda dull and mostly melts through the plastic
Sharp blades tend to bite and shatter plastic.
I also use a fine blade on a jig saw. keep the plastic coverage
on the sheeting until after the cuts have been made.
if its to late masking tape will keep the jig saw base from maring the
surface.
Same thing applies to drilling holes for mounting. you want to round
the edges on the drill bit slightly so you get the melting effect
othewise the bit can grab and shatter out your hole.
unfortuneately drilled holes are usually near the edge they end up
blowing out pieces
thats all the wisdom I have for you on the matter good luck
For shaping infared h eat works to soften the plastic
be warned if it isnt warm enough when attempt a bend it will
crystalize on the outer radius and get foggy in the corner and possibly even break.
Another small bit of info that applies. Always heat the plastic from the side that is gonna be the longest radius of a bend..
this little tidbit cost me a buck or two in wasted plastic to learn.
- Thread starter
- #3
Thanks Dirtsquirt. I think I have a couple of old dull drill bits for the holes.
I've done quite a bit of cutting on sheet acrylic, and have to disagree with the plywood blade suggestion. A blade made for cutting plastic looks very similar to a high-tooth-count wood blade, with a different rake. I've had good results with using sharp carbide blades made for cross cutting (mitering) wood. They will dull faster than when used with wood, but the average hobbyist won't notice. It makes for a nice, clean cut with no melted boogers all over the place.
I don't know how big your holes have to be, but for 1/2" holes I've found that a countersink works great. I don't know if you can find smaller diameter countersinks though.
Also, you can use a small torch, like a jewler's torch, to smooth the saw marks from the cut edges. Try it on some scrap first- in fact, try some practice cuts and bends too before you get into the project.
-Spike
I don't know how big your holes have to be, but for 1/2" holes I've found that a countersink works great. I don't know if you can find smaller diameter countersinks though.
Also, you can use a small torch, like a jewler's torch, to smooth the saw marks from the cut edges. Try it on some scrap first- in fact, try some practice cuts and bends too before you get into the project.
-Spike
I use a high tooth count (metal blade) on my bandsaw. Works good (except for me getting in a hurry sometimes), gonna try Spikes idea with a small butane torch on the next ones edges, that is my real problem is clean edges.
I use a buffing wheel and that does OK. But not like the ones we buy from the sign people. Sure my smaller Oxt/Acet would be way to hot.
For bends, I use a heat gun and start slow. As said above, heated side should be the outside of the bend.
I use a buffing wheel and that does OK. But not like the ones we buy from the sign people. Sure my smaller Oxt/Acet would be way to hot.
For bends, I use a heat gun and start slow. As said above, heated side should be the outside of the bend.
Hydrogen
Hydrogen and oxygen in a jewelers torch is what we use to
clean up the edges..
Smooth as a babies backside.
I may have exagerated a little on the dullness of the blade
We dont buy blades to cut lexan or acrylic we use a Plywood blade
(high tooth count).
We only make stuff for in house use and are by no means professional plastic workers.
As a mill wright we have to do it all.. somethings we better than others but in the end it has to be workable and passable craftmanship.
and as I stated. sharpness of the blade isnt a huge consideration (for me)
you can cut with a range of edge finishes If the edge gets to rough change the blade.. but generally a little torch goes a long way.
Happy Fabbing
Hydrogen and oxygen in a jewelers torch is what we use to
clean up the edges..
Smooth as a babies backside.
I may have exagerated a little on the dullness of the blade
We dont buy blades to cut lexan or acrylic we use a Plywood blade
(high tooth count).
We only make stuff for in house use and are by no means professional plastic workers.
As a mill wright we have to do it all.. somethings we better than others but in the end it has to be workable and passable craftmanship.
and as I stated. sharpness of the blade isnt a huge consideration (for me)
you can cut with a range of edge finishes If the edge gets to rough change the blade.. but generally a little torch goes a long way.
Happy Fabbing
I you are looking for a gentle cut, you may want to consider masonary cutting blade for a circular saw. It is like a thin grinding wheel.
I'm guessing you're talking about an abrasive blade, rather than a diamond blade. Never tried that.
-Spike
i cut acrylic with a router, works fine for me.
- Thread starter
- #10
I ended up using my jig saw with a 10t blade and sorta pulsing it. I scrapped the bends/shaping idea and just cut out a rectangle.
Yep, that's the best way to get a very good edge. A bit more complicated than using a table saw for the average Joe though.
-Spike
David, looks good from the picture, you can hide a lot with that trim.
HF had a $89 micro torch I was looking for a reason to buy (will hook to my MC oxt/acet tanks). Just tight on money and that seems high in price.
I will try butane and the Spike method next time I have to cut some and post results.
I heard a router it best, the acrylic/lexan shop local does it that way. Just for small things they want too much money.
Not to hijack the thread. Will the router make a clean bevel/edge, or you still have to heat it?
Anyone used a heat gun, I use that bend, never tried on the edges. Something to try on a scrap piece tonight.
HF had a $89 micro torch I was looking for a reason to buy (will hook to my MC oxt/acet tanks). Just tight on money and that seems high in price.
I will try butane and the Spike method next time I have to cut some and post results.
I heard a router it best, the acrylic/lexan shop local does it that way. Just for small things they want too much money.
Not to hijack the thread. Will the router make a clean bevel/edge, or you still have to heat it?
Anyone used a heat gun, I use that bend, never tried on the edges. Something to try on a scrap piece tonight.
The router edge will be clean, but the torch can make it clear.
-Spike
-Spike
I did the butane today, was smooth but not as clear as I hoped (this was after a steel bandsaw cut though). For what we do it was a lot better though.
Then even tried shaving it with a razor blade, holding it vertical. Butane was better but the edges seemed a little thicker..
Heat gun was about the same but took a lot longer and it wanted to bend.. So, light torch moving a lot makes a better (smooth) edge. Maybe I will hit it with a buffer and paste tomorrow for fun.
Then even tried shaving it with a razor blade, holding it vertical. Butane was better but the edges seemed a little thicker..
Heat gun was about the same but took a lot longer and it wanted to bend.. So, light torch moving a lot makes a better (smooth) edge. Maybe I will hit it with a buffer and paste tomorrow for fun.