Using jointer to finish Acrylic edges before assembly

[Koleswrath]

I've seen it mentioned as possible but haven't seen any first hand experiences of using a jointer to finish acrylic edges before gluing. I have an excellent 12" that I've spent hours setting up and tweaking to perfection over the last few years. It's got a helical cutterhead with carbide inserts and a 5" or 6" tall fence that's consistently square over it's entire length. I'm planning a 16" tall sump so it won't be difficult to keep the panel tight to the fence with a 16" tall panel.
Is this not more common because everyone is using CNC's these days? Or is there too much possibility to take a panel out of square when jointing all 4 sides of the panel?
Would love to hear some experiences!
Thanks!

 

[Timfish]

I haven't tried using a joiner on acrylic so I'd suggest trying a few scrap pieces and gluing them to see how the joints look. FYI An alternate glue to the solven types are the self polermerizing glues like #40 and #44. You might consider one as it gives a stronger bond but the techniques are a bit different than the solvent types.

 

[Koleswrath]

You might consider one as it gives a stronger bond but the techniques are a bit different than the solvent types.

Thanks for the suggestion! I was planning bunch of test pieces for sure. This will be my first crack at gluing acrylic.
Would you say the #40 and 44 (this is the 2 part like epoxy right?) is an easier method than the #3/4? I work with epoxy a lot for whatever that's worth.

 

[Troylee]

Thanks for the suggestion! I was planning bunch of test pieces for sure. This will be my first crack at gluing acrylic.
Would you say the #40 and 44 (this is the 2 part like epoxy right?) is an easier method than the #3/4? I work with epoxy a lot for whatever that's worth.

Spiral bits with a back gauge will give you clean cuts for solvent welding.. 40-42 is okay on thicker stuff but I prefer 3/4. Glue a piece up and let it sit a couple day and break it and see what happens… it should leave the weld and take the plastic off around it..

 

[Koleswrath]

Spiral bits with a back gauge will give you clean cuts for solvent welding

I've got 1/2" carbide spiral upcut bits and a pretty flat router table extension on my cabinet saw. Was just curious about the jointer since it's so easy and setup is nothing.
I can also get glue ready cuts with no saw marks right from my saw (on maple) if I keep pressure consistent and don't stop during a cut. Do edges always need milling after cutting? (eg. for a specimen container or something small?)

 

[Troylee]

I've got 1/2" carbide spiral upcut bits and a pretty flat router table extension on my cabinet saw. Was just curious about the jointer since it's so easy and setup is nothing.
I can also get glue ready cuts with no saw marks right from my saw (on maple) if I keep pressure consistent and don't stop during a cut. Do edges always need milling after cutting? (eg. for a specimen container or something small?)

To be completely honest no! Is it a good practice? Prolly not.. but I have glued up table saw cuts plenty of times… new triple chip blade blade and don’t start and stop and you’d be okay on little stuff.. I wouldn’t never do anything big that way for the shear fact of the heat generated by cutting thicker material and solvent welding will cause crazing and weaken your joints..

 

[Koleswrath]

new triple chip blade

Thanks, really appreciate the guidance! I have an 80 tooth Freud blade for melamine that has a triple chip grind. Only working with 1/4" so I'll give it a shot.
I guess my last question would be: If the joint tests ok when I try to break a test piece and if it looks ok for the finished product is it safe to assume its good to go or could there be unseen issues that might creep up years down the road? I'm not sure what brand or type of acrylic I have - just got a bunch for free which started me down this path - it has a white plastic sheet not paper which is concerning as I learn more about extruded vs cast, etc.
Again, this is going to be a very small sump so I might be overthinking a bit here.
Thanks again!

 

[Troylee]

Thanks, really appreciate the guidance! I have an 80 tooth Freud blade for melamine that has a triple chip grind. Only working with 1/4" so I'll give it a shot.
I guess my last question would be: If the joint tests ok when I try to break a test piece and if it looks ok for the finished product is it safe to assume its good to go or could there be unseen issues that might creep up years down the road? I'm not sure what brand or type of acrylic I have - just got a bunch for free which started me down this path - it has a white plastic sheet not paper which is concerning as I learn more about extruded vs cast, etc.
Again, this is going to be a very small sump so I might be overthinking a bit here.
Thanks again!

Not sure what acrylic you have.. normally polycarbonate has the plastic on it not acrylic.. I have seen some cheap acrylic with blue plastic thou. Cast is always the best to use.. look up the pins and needles thread or I have a huge acrylics 101 on here some where.. getting good clean joints is the hardest part! If your joints are bubble free and the material is properly sized for the job you shouldn’t have any issues down the long haul..

 

[Reign1]

In my experience the spiral plastic router bit is the way to go. Been there done that on the melamine table saw blade. By far the router cuts nice and clean huge difference between the two.
I am lucky Craftics is local to me they sell all of the products for this ..

CRAFTICS - Tools and Accessories for Working with Plastic

 

[Koleswrath]

Thanks all, I haven't ruled out that it's polycarbonate but since polycarbonate is more expensive and these panels were being used as covid distancing guards I can't see why they would spend more for the polycarbonate. If it turns out not to be acrylic I'll just go buy a sheet of plexiglas cast.

spiral plastic router bit is the way to go

Is this a downcut spiral? What makes it plastic specific?

 

[Troylee]

Thanks all, I haven't ruled out that it's polycarbonate but since polycarbonate is more expensive and these panels were being used as covid distancing guards I can't see why they would spend more for the polycarbonate. If it turns out not to be acrylic I'll just go buy a sheet of plexiglas cast.



Is this a downcut spiral? What makes it plastic specific?

I prefer these..

 

[Koleswrath]

Ya, this is what I use for almost everything I do in wood. Not the flush trim but just a spiral upcut bit. Not plastic specific or anything just solid carbide awesomeness.

Whiteside isn't common up here in the frosty north so I buy Dimar or CMT mostly.

 

[Troylee]

Ya, this is what I use for almost everything I do in wood. Not the flush trim but just a spiral upcut bit. Not plastic specific or anything just solid carbide awesomeness.

Whiteside isn't common up here in the frosty north so I buy Dimar or CMT mostly.

Those will work fine.. onsurd does make specialty bits for plastic, aluminum etc.. they don’t come with a bearing set up thou.. I use a ton of triple flute armana myself for smaller projects and the spiral when I’m doing 1/2”” or thicker acrylic.

 

[Timfish]

Thanks for the suggestion! I was planning bunch of test pieces for sure. This will be my first crack at gluing acrylic.
Would you say the #40 and 44 (this is the 2 part like epoxy right?) is an easier method than the #3/4? I work with epoxy a lot for whatever that's worth.

I prefer #40 or 44 as they are stronger but there is more prep work involved and applying them is slightly longer do to the thicker viscosity.

I prefer these..

Eveyr time I've dug into the differences with wood vs metal vs platic blades the differences are the angles use for the cutting edges. I haven;t ever tried different them to see if there's noticable differences in the final product.

The big test is how the final joint looks. Like Traylee pointed out if the joint is bubble free and there's crazing (tiny stress lines) and you sized the thickness right you're good to go.

 

[Troylee]

I prefer #40 or 44 as they are stronger but there is more prep work involved and applying them is slightly longer do to the thicker viscosity.



Eveyr time I've dug into the differences with wood vs metal vs platic blades the differences are the angles use for the cutting edges. I haven;t ever tried different them to see if there's noticable differences in the final product.

The big test is how the final joint looks. Like Traylee pointed out if the joint is bubble free and there's crazing (tiny stress lines) and you sized the thickness right you're good to go.

Not aware of 44? You mean 42? I use it daily

 

[Timfish]

Oooooops! Yes, that's what I meant. I've always preferred to use #40.