Acrylic fabrication questions? I can help!

[Floyd R Turbo]

If you used 40, you have to form a gap between the panes as it is not supposed to be used for flush bonding joints (so you have to put a few degrees of excess angle on the cut edge of the joint) and then fill the gap, then wet sand out the excess, then polish. Then if you want to completely avoid bubbles in the joint, after you mix the 40 and before it starts to set, you have to centrifuge it or put it in a vacuum chamber to get all the bubbles to rise to the surface.

40 is not easy to use and make it look professional. Also if you doin't know what you're doing, it will look great when you get it all done but when you fill it with water, it can just fall apart (immediately or a few months down the road).

Solvent welds, on the other hand, you can tell they are good right away.

 

[paphater]

Yeah I know all about bubbles and 40. I was paranoid with my first tank so I poured small fillets of 40 and bubbles galore. How would you recommend to prep the edges?

 

[Floyd R Turbo]

For solvent weld?

 

[paphater]

Yeah. I'm not sure how I would go about finishing the angled edges except for hand scraping them.

 

[GoldsteinReef]

Think you can help me out?

This is a brand new acrylic tank.. it's wrapped with plastic wrap, so don't let that throw you off.

http://www.reefcentral.com/forums/showthread.php?t=2693829

 

[GlassReef]

Big problems with bubbles.

Big problems with bubbles.

Seven or eight years ago, I was always working on acrylic projects - all the way from dosing containers to a number of large sumps. These projects always turned out (in my estimation) close to perfect. So... I recently decided to jump back in and build a 100 gal sump out of 3/8" acrylic. I'm finding it almost impossible to glue a seam without hundreds of bubbles!

My edges have been routered (very smooth and straight). I'm using fresh Weld-On 4, a .22mm solvent needle, .25mm acupuncture needles for Pins. As soon as I start injecting the solvent, the bubbles start. Nothing I've done has helped.

I'm doing every thing the way I used to, except the acrylic is Chinese and I used isopropyl achohol to clean the edges before gluing.

Any help or tips would be great!

 

[Floyd R Turbo]

Huh...that's odd. A few things you might try:

1) Clean the edge (and the other surface you are bonding to) with denatured alcohol instead of isopropyl. Isopropyl contains other ingredients which might be leaving a bit of residue, i.e. water.

2) blow off the edge/surface with compressed air after cleaning

3) when you set up the joint (assuming you are using a right-angle jig and the pins method) the last step before filling the joint with solvent should be to blow it out with canned air, this will de-ionize the material to an extent and get rid of any dust particles, which will hold air around them via static electricity

4) when you start the solvent, squeeze some air out, tip the bottle over to needle in position a hair beyond the edge of the joint while releasing the pressure, then start squeezing such that the tip of the needle is barely at the start of the joint, let the solvent suck into the joint ahead of the path of motion you will follow, then start moving, keeping the "bead" about 1/4" to 1/2" ahead of the needle. Finish up by ending the pass to the edge of the joint before fully releasing the presure.

Some of these you probably already know, but all the same, that's what I do

 

[GlassReef]

Thank you, Sir. Your point about "denatured alcohol instead of isopropyl. Isopropyl contains other ingredients which might be leaving a bit of residue, i.e. water" caused my brain to start working again. My bottle of isopropyl is only a quarter full and about 5 years old. Probably 20% water by now. Ran down to the big box and bought some denatured - problem solved...

Thanks again.

 

[shellydsilva]

Hi,

I am using capillary method to glue the 5mm acrylic pieces. But I end up like this joint. When the glue is applied, I can see that the glue is covering the entire width of the acrylic sheet. But once the glue dries, I get the edge finish like this.

What could be the reason? I trim the edge using a flush trim router bit after the piece is cut using laser. Using Weldon glue.

 

[shellydsilva]

Hi,

I am using capillary method to glue the 5mm acrylic pieces. But I end up like this joint. When the glue is applied, I can see that the glue is covering the entire width of the acrylic sheet. But once the glue dries, I get the edge finish like this.

What could be the reason? I trim the edge using a flush trim router bit after the piece is cut using laser. Using Weldon glue.

 

[Floyd R Turbo]

Capillary welds look like this because the bond is instant and there is no dissolving of material to create a fillet. You need to use the pin & soak method. Capillary welds are not sufficient for tank building at all.

 

[shellydsilva]

[MENTION=17654]Floyd[/MENTION], thanks for the response. Can I add Acetic acid to reduce the evaporation rate? What percentage would you recommend?

For pin and soak method, how long do we need to soak the acrylic piece in the solvent? And I hope, we just need to dip the acrylic piece about 1mm deep in the solvent.

Also how can we follow the soak method for larger tanks? If the acrylic piece is 48 inch long, how can we follow the soak method?

 

[Floyd R Turbo]

The info about the pins method is in this thread, but you'll have to dig for it. It is not about soaking the piece in a vat of solvent. Quick version: you use pins to create a gap and then wick the solvent into the gap, let it soak for 20-30 seconds or so (depends on a few factors) and then pull the pins. There is a lot more to it, that is just the quick explanation of the process

 

[shellydsilva]

The info about the pins method is in this thread, but you'll have to dig for it. It is not about soaking the piece in a vat of solvent. Quick version: you use pins to create a gap and then wick the solvent into the gap, let it soak for 20-30 seconds or so (depends on a few factors) and then pull the pins. There is a lot more to it, that is just the quick explanation of the process

I followed the same method that you had mentioned. I used the acupuncture needles for this method. When I apply the solvent, I can see that it spreads across the thickness of the acrylic sheet. After 30 secs, I pull out the needles. But once the solvent dries, I dont get the full finish.

 

[Floyd R Turbo]

What thickness/diameter are acupuncture needles? I'm thinking those have a very small diameter, that night be the problem.

When you pulled the pins out, did the material drop slightly, and was there a "squish out" of gooey material?

 

[shellydsilva]

What thickness/diameter are acupuncture needles? I'm thinking those have a very small diameter, that night be the problem.

When you pulled the pins out, did the material drop slightly, and was there a "squish out" of gooey material?

[MENTION=17654]Floyd[/MENTION], it was a 0.25mm needles. Material drop, I would say that very less and as mentioned, I do not see a "squish out" of gooey material.

This was the needle used https://www.oceanichealthcare.in/product/sterile-acupuncture-needles-for-single-use0-25-x-25/

 

[Floyd R Turbo]

I'll have to double check but I don't think that is overly small - 30 gauge wire - but I can't recall what I use (I have a few spools for different materials)

I want to say 28 and 26 is what I use. I'll get back to you.

 

[shellydsilva]

I'll have to double check but I don't think that is overly small - 30 gauge wire - but I can't recall what I use (I have a few spools for different materials)

I want to say 28 and 26 is what I use. I'll get back to you.

Sure. Thanks.

 

[toby.toby]

does anyone know if acrylicman is still active here? i'm interested in the books/leaflets he was going to do on fabrication.

thanks

 

[Floyd R Turbo]

acrylicman is long gone, not sure what happened to him

"Acrylics" is James Steele with Envision Acrylics. Definitely one of the most knowledgeable people in the industry. I've learned most of what I know (at least what you can't get from experience) from him.