Acrylic Fabrication Q & A

[TaylorPilot]

There is a lot of margin in this stuff as long as you prep well. I have good luck with soak times 20-30 seconds all the way up to 75 -90 seconds if I get behind. I would be hard pressed to go much past that though. After 90 seconds the melted acrylic is starting to get pretty thick. It does leave a nicer seam with less chance for blushing on black acrylic from reduced squeeze out, but I feel like I am running up against the limits of how long I will let it soak. 30-45 seconds seems good to me in my climate controlled assembly room. I mix my own stuff usually around 5-6%. The solvent you use is a big factor as well. I hate the pre-mixed stuff on dark acrylic.

 

[Turbo's Aquatics]

Think of this. When you weld the top and bottom on if it’s a big tank it takes 3min to just wick the solvent In. At least it does for me. Then by the time I pull the pins and tighten the clamps it’s over 5 mins. Unless you guys get help…

Actually on the last big tank I did, which was an 8' 240g with 3/4" walls, 2 of us ran the entire seam with 16 gauge needles in about 20 seconds flat. If I had to do it myself, I could have had all the solvent in the joint in under 45 seconds.

That said, I know what you're saying on a super long soak time just due to the time between start/finish of a long joint. But for me, that's when I start running into air intrusion along the edge and I have to run a quick-pass of solvent right before pulling the pins, and then load up extra weights to get even the slightest amount of squish. So I opt for larger needles and moving fast then pulling the pins right away.

On my larger sumps (40" x 20" footprint of 1/4", so a 10' joint + baffles) I can run that joint with my special 20 gauge needles that dump a bit faster and get that joint & baffles ran in under 30 seconds and start pulling the pins before any air starts intruding

There is a lot of margin in this stuff as long as you prep well. I have good luck with soak times 20-30 seconds all the way up to 75 -90 seconds if I get behind. I would be hard pressed to go much past that though. After 90 seconds the melted acrylic is starting to get pretty thick. It does leave a nicer seam with less chance for blushing on black acrylic from reduced squeeze out, but I feel like I am running up against the limits of how long I will let it soak. 30-45 seconds seems good to me in my climate controlled assembly room. I mix my own stuff usually around 5-6%. The solvent you use is a big factor as well. I hate the pre-mixed stuff on dark acrylic.

I haven't even used premixed in a decade I bet. I've knocked my AA% down to 2.5-3%

 

[TaylorPilot]

Actually on the last big tank I did, which was an 8' 240g with 3/4" walls, 2 of us ran the entire seam with 16 gauge needles in about 20 seconds flat. If I had to do it myself, I could have had all the solvent in the joint in under 45 seconds.

That said, I know what you're saying on a super long soak time just due to the time between start/finish of a long joint. But for me, that's when I start running into air intrusion along the edge and I have to run a quick-pass of solvent right before pulling the pins, and then load up extra weights to get even the slightest amount of squish. So I opt for larger needles and moving fast then pulling the pins right away.

On my larger sumps (40" x 20" footprint of 1/4", so a 10' joint + baffles) I can run that joint with my special 20 gauge needles that dump a bit faster and get that joint & baffles ran in under 30 seconds and start pulling the pins before any air starts intruding


I haven't even used premixed in a decade I bet. I've knocked my AA% down to 2.5-3%

When you reduced it down to 3%, did you see some kind of improvement?

 

[Turbo's Aquatics]

Yeah, I was getting a weird effect that I call "muddling" where after the joint is fully cured, you could see a distortion if you looked at the joint at the right angle with the right light. Not really a haze, kinda of a "blotchy" look. Not a structural issue but it had just always annoyed me not having crystal clear joints.

In discussion with James he mentioned that you really don't need to have a soak time over 15-20 seconds, and the longer soak time could be causing the issue I was seeing. So I cut down AA to get a stronger bite and it worked. Bonus is that I don't have to wait to pull pins, there aren't many joints that take longer than 15 seconds to run.

Now, that all might change once I figure out what material to start using...once I can get my hands on any. Black 1/4" is near impossible to get a hold of right now.

 

[Cabinetman]

Actually on the last big tank I did, which was an 8' 240g with 3/4" walls, 2 of us ran the entire seam with 16 gauge needles in about 20 seconds flat. If I had to do it myself, I could have had all the solvent in the joint in under 45 seconds.

That said, I know what you're saying on a super long soak time just due to the time between start/finish of a long joint. But for me, that's when I start running into air intrusion along the edge and I have to run a quick-pass of solvent right before pulling the pins, and then load up extra weights to get even the slightest amount of squish. So I opt for larger needles and moving fast then pulling the pins right away.

On my larger sumps (40" x 20" footprint of 1/4", so a 10' joint + baffles) I can run that joint with my special 20 gauge needles that dump a bit faster and get that joint & baffles ran in under 30 seconds and start pulling the pins before any air starts intruding


I haven't even used premixed in a decade I bet. I've knocked my AA% down to 2.5-3%

You guys must’ve been moving to get it done in 20 seconds.

 

[Turbo's Aquatics]

You guys must’ve been moving to get it done in 20 seconds.

Yup - have you ever used 16 gauge needles? The solvent dumps out fast, you have no choice but to move fast.

James has told me about running a 20' joint with 2" acrylic with one other person, from start to pins out in 60 seconds. He uses large squeeze bottles like the ones for dispensing ketchup & mustard

 

[Troylee]

You guys must’ve been moving to get it done in 20 seconds.

16ga needles.. floods the joint faster..

 

[Cabinetman]

16ga needles.. floods the joint faster..

I’ve used them before but found sometimes I’d get bubbles shoot into the seem. Now I just use big syringes with the plastic tip that sticks out. Like I said I don’t rush because I want the soak time. And it’s not because I havnt experimented using quicker soak times because I have and I found the joints didn’t turn out near as good as when I let the solvent go longer before pulling the pins. I guess building tanks is like keeping reefs. There’s more than one way to be successful

 

[Cabinetman]

Yup - have you ever used 16 gauge needles? The solvent dumps out fast, you have no choice but to move fast.

James has told me about running a 20' joint with 2" acrylic with one other person, from start to pins out in 60 seconds. He uses large squeeze bottles like the ones for dispensing ketchup & mustard

What do you do to protect the panels from solvent if it creeps out? Solvent burn is something I try to avoid like the plague and squirting solvent that fast… well I know from experience it can be a problem

 

[Lowell Lemon]

There is a polyethylene tape at FTM online that works great for the splash over.

 

[Cabinetman]

There is a polyethylene tape at FTM online that works great for the splash over.

I use a lot of painters tape when I build. It seems to protect the plastic against the solvent. I know the masking sure doesn’t

 

[TherealplexiG]

I’ve used them before but found sometimes I’d get bubbles shoot into the seem. Now I just use big syringes with the plastic tip that sticks out. Like I said I don’t rush because I want the soak time. And it’s not because I havnt experimented using quicker soak times because I have and I found the joints didn’t turn out near as good as when I let the solvent go longer before pulling the pins. I guess building tanks is like keeping reefs. There’s more than one way to be successful

The longer the soak time the weaker the joint compared to smaller ones. Better edge prep leaves nice joints in smaller soaks. For junk i'd give it a 50-60 seconds, for the brands i would not exceed 40. i use a timer so no ball park. This all directly relates to acrylic thickness and pin diameter. The timings i put for 1/2 in thick coz that's what i work on mostly.
The Real PlexiG~~

 

[TherealplexiG]

@Lowell Lemon @cromag27 @TaylorPilot
How's ya'll doing?
@Turbo's Aquatics
Peace.

 

[cromag27]

@Lowell Lemon @cromag27 @TaylorPilot
How's ya'll doing?
@Turbo's Aquatics
Peace.

hey!!!!

 

[Cabinetman]

The longer the soak time the weaker the joint compared to smaller ones. Better edge prep leaves nice joints in smaller soaks. For junk i'd give it a 50-60 seconds, for the brands i would not exceed 40. i use a timer so no ball park. This all directly relates to acrylic thickness and pin diameter. The timings i put for 1/2 in thick coz that's what i work on mostly.
The Real PlexiG~~

That’s not my experience at all because I’ve tested joints where I only do quick soak and then I tried to let it soak for an extended period and the extended one is stronger.

 

[cromag27]

i soak for 15 mins. just sayin.

 

[Lowell Lemon]

@Lowell Lemon @cromag27 @TaylorPilot
How's ya'll doing?
@Turbo's Aquatics
Peace.

Doing well glad to see you about!

 

[TaylorPilot]

@Lowell Lemon @cromag27 @TaylorPilot
How's ya'll doing?
@Turbo's Aquatics
Peace.

Dying of heat stroke baby sitting this CNC in my garage in Houston Tx heat and 75% humidity...I need an air conditioned shop...LOL

 

[TaylorPilot]

Also, what is everyone's favorite brand of applicator bottle...

 

[cromag27]

Also, what is everyone's favorite brand of applicator bottle...

whatever’s cheap in amazon. i replace them on a regular basis so i’ve never had a problem with the cheapies. i get good deals on wo 45 applicators on amazon as well.