Acrylic Fabrication Q & A

[cromag27]

What material did you use for your table top?

 

[Lowell Lemon]

What material did you use for your table top?

My table top is just high pressure laminate with years of abuse on a 2" tubular steel table frame with leveling feet. I need to replace the top one of these days.

 

[cromag27]

I use a fence and posted a picture on this thread [HASHTAG]#133[/HASHTAG]. Take a look and see what you think. Use a 1/2 two flute plastic grind router bit from FTM Plastics...they have a website. It provides the best control for removal of saw cut edges ready to solvent weld. If you want to spend the money just buy a CNC machine and you should be ready to bond right off the machine. You might have to make a second pass on some machines to get a smoother finish. Edge Finisher Corp makes a edge polisher that will prep the edges and polish them. You can also use a joiner with spiral carbide blades to achive a finish ready for bonding.
Quite a few options out there.

I couldn't find this bit on their website.

 

[melev]

I use a fixed fence opposite the bit and pass the sheet between the two. Mine is a 4" wide piece of 1" black acrylic (actually 2x 1/2" bonded together) that I refer to as the Black Mamba

Can't get this to embed but I think this will open the vid in a new window ooooh I figured it out!

I saw this video on Facebook. What's your name over there again?

 

[cromag27]

I saw this video on Facebook. What's your name over there again?

Bud carlson

 

[Lowell Lemon]

I couldn't find this bit on their website.

Whiteside SC25 1/2" shank, 1" cutter length, 3" overall length $37 and change. Make sure you look at the Whiteside list and not just Onsrud.

You could also use one of the spiral flute designs. Might be harder to set the fence if one flute is cutting deeper than the other (possible machine error in manufacturing process).

 

[cromag27]

Which flush trim bit do you use? I've never used these plastic specific bits. think I'll give them a try.

 

[Lowell Lemon]

Which flush trim bit do you use? I've never used these plastic specific bits. think I'll give them a try.

I like to use the bits with a 1" cutter length and two flute with 1/2" shank. They seem to put less stress on the smaller Porter Cable Routers I use. I also have three or four of the production Proter Cable Routers for other uses like longer and larger router bits. Both Onsrud and Whiteside work great and last a long time if you just cut acrylic.

 

[imustbenuts]

Hey Bud,

Any idea when you might get to edge prep and joint prep? I have a project I'm working on currently and getting ready to weld it together. I have cut my pieces and routed the edges I need to bond. I saw in the pins method to blow out the joint with can air but wasn't sure if any other cleaning needed to done.

 

[Adkins]

I'm feeling like DYI in this scenario is just a little above me at the moment. Is it ok for me to ask if someone here could contact me about quoting a small project?

 

[Turbo's Aquatics]

Hey Bud,

Any idea when you might get to edge prep and joint prep? I have a project I'm working on currently and getting ready to weld it together. I have cut my pieces and routed the edges I need to bond. I saw in the pins method to blow out the joint with can air but wasn't sure if any other cleaning needed to done.

The short version is that edge prep is basically routing the edge so that it's straight and free of divots & saw marks, etc, and the edges are square and sharp. You can also do this with a jointer or also a razor blade, those are less reliable methods compared to passing the part between a router bit and a fence on a table but are better than saw cut.

Joint prep is basically dry-fitting the piece into the post-bond position to verify that it fits right (you don't need an angle bracket at this point). Then clean surfaces with denatured alcohol on a cotton cloth to get rid of fingerprints, grease, dust, etc, then blow off with compressed air. Put the joint back together, this time with the angle bracket, and sung everything up with shim if needed. If something is off, like a ridge in the cut edge that needs trimming, then you have to go back to scraping and repeat the above until it's good.

Once it's good, insert the pins every ~6" (sometimes less) and shim if needed so that they are all snug (super thin shims), then blow out the joint with canned air, run the solvent, wait 15-20 seconds, pull the pins, and adjust the joint to make sure it's in the right position (you have about 10 seconds to do this). After a few minutes, set some weight on top (optional, but sometimes required if the cut edge piece is not perfect) and sometimes it helps to run a very quick bead of solvent along the joint to help prevent air creep (this is where it helps to have an angle bracket that allows access to that side of the joint - but that's not 100% necessary)

Pulling the pins without pulling the joint completely apart is something that just takes practice. For bottom/top panels, it's the last pin that matters because then the top part can drift. With an end-to-front bond (first couple joints) I put my finger on the edge of the flat panel with my fingertip touching the vertical panel and pull the pin with the other hand, making sure not to push with my bracing hand (you are just preventing the panel from pulling toward you along with the pin)

 

[cromag27]

It sucks when you pull a pin and the entire panel moves. lol.

 

[Turbo's Aquatics]

It sucks when you pull a pin and the entire panel moves. lol.

It's not the end of the world all the time, unless the panel falls. Once, I pulled a joint completely out of position on one corner and moved it back into place and still had a perfectly clear joint....once

 

[imustbenuts]

The short version is that edge prep is basically routing the edge so that it's straight and free of divots & saw marks, etc, and the edges are square and sharp. You can also do this with a jointer or also a razor blade, those are less reliable methods compared to passing the part between a router bit and a fence on a table but are better than saw cut.

Joint prep is basically dry-fitting the piece into the post-bond position to verify that it fits right (you don't need an angle bracket at this point). Then clean surfaces with denatured alcohol on a cotton cloth to get rid of fingerprints, grease, dust, etc, then blow off with compressed air. Put the joint back together, this time with the angle bracket, and sung everything up with shim if needed. If something is off, like a ridge in the cut edge that needs trimming, then you have to go back to scraping and repeat the above until it's good.

Once it's good, insert the pins every ~6" (sometimes less) and shim if needed so that they are all snug (super thin shims), then blow out the joint with canned air, run the solvent, wait 15-20 seconds, pull the pins, and adjust the joint to make sure it's in the right position (you have about 10 seconds to do this). After a few minutes, set some weight on top (optional, but sometimes required if the cut edge piece is not perfect) and sometimes it helps to run a very quick bead of solvent along the joint to help prevent air creep (this is where it helps to have an angle bracket that allows access to that side of the joint - but that's not 100% necessary)

Pulling the pins without pulling the joint completely apart is something that just takes practice. For bottom/top panels, it's the last pin that matters because then the top part can drift. With an end-to-front bond (first couple joints) I put my finger on the edge of the flat panel with my fingertip touching the vertical panel and pull the pin with the other hand, making sure not to push with my bracing hand (you are just preventing the panel from pulling toward you along with the pin)

Thanks for the info. I glued up my first joint last night. However, I missed your reply and I didn't use denatured alcohol to clean the surface. This project is just an internal overflow box. I can use some 16 on the joint hopefully to make it stronger. I'm using the pins method to practice for the sump I'll eventually be building.

 

[cromag27]

Whiteside SC25 1/2" shank, 1" cutter length, 3" overall length $37 and change. Make sure you look at the Whiteside list and not just Onsrud.

You could also use one of the spiral flute designs. Might be harder to set the fence if one flute is cutting deeper than the other (possible machine error in manufacturing process).

So I picked up one of those 1/2" whiteside bits and it made these very fine ridges. barely can feel them with your finger. I made an ato container from 3/8" and they all welded together cleanly so they didn't appear to make a difference. do you get these ridges as well?

 

[imustbenuts]

So I picked up one of those 1/2" whiteside bits and it made these very fine ridges. barely can feel them with your finger. I made an ato container from 3/8" and they all welded together cleanly so they didn't appear to make a difference. do you get these ridges as well?

I have the same question. I used a spiral up cut bit and had the same ridges. I wasn't bonding anything that needed a water tight bond so I didn't worry about it. However, I want to build a sump and am concerned about bonding that edge.

 

[Lowell Lemon]

@cromag08
Yes the ridges are a way of life with the router edges...however as you have experianced the bond is great with no bubbles if you use the pin and solvent method.

@imustbenuts

You will have no problem with strength of bond or with bubbles as long as you use the pin and solvent method outlined by Floyd R Turbo. The quality of bond will be water clear with the proper routed edge. Just make sure you peel the paper back from the edges to prevent the solvent from being absorbed by the paper or film masking.

 

[Turbo's Aquatics]

So I picked up one of those 1/2" whiteside bits and it made these very fine ridges. barely can feel them with your finger. I made an ato container from 3/8" and they all welded together cleanly so they didn't appear to make a difference. do you get these ridges as well?

Everything I route looks like this!

@cromag08
Just make sure you peel the paper back from the edges to prevent the solvent from being absorbed by the paper or film masking.

I peel back about 1" and then take a razor blade (using a ratcheting box cutter, the one with the blade you can retract/extend and break off pieces for a new edge) and slice about 1/2" off then stick it back down (so that the flush trimming process doesn't marr anything) but yes, extremely important that you don't bond the paper

 

[Adkins]

Decided to try my hand at making something that required gluing.

 

[Reefahholic]

Great thread man!