DIY Tank (Dialup beware), Step by Step

[Acrylics]

From all that I hear, IPS has stopped making 5 altogether so...but yes - it does allow for a little more working time IME. Any time you add acetic acid, you'll slow the reaction down. Practice practice

As Marc said, probably 90-95% of the solvent goes right into the joint.

As for getting a 20ga applicator needle, not likely unless you make it yourself (unless someone has become smart and makes them now). You'll have to get a 20ga syring from a pharmacy/MD, whatever and grind the pointy part off and then replace the original needle in the bottle top. PITA but I only have to do once a yr or so.

James

 

[Chatouille]

FWIW... I just checked, and the B-D 20g 1-1/2" PrecisionGlide needles screw straight on the small solvent applicator bottle I bought awhile back. So all you would need to do is round off the point.

Didn't know that weldon 5 wasn't available any longer... What about the reaction time of McBond? I remember that you had previously said that it was also a good solvent to use.

Question... would slowing down the reaction end up in making it actually dissolving more acrylic??? If so... you wouldn't want to use it on extruded material, (or lucite) correct???

Chris

 

[Acrylics]

<a href=showthread.php?s=&postid=11664526#post11664526 target=_blank>Originally posted</a> by Chatouille
FWIW... I just checked, and the B-D 20g 1-1/2" PrecisionGlide needles screw straight on the small solvent applicator bottle I bought awhile back. So all you would need to do is round off the point.

Didn't know that weldon 5 wasn't available any longer... What about the reaction time of McBond? I remember that you had previously said that it was also a good solvent to use.

IIRC McMond and WO5 were exactly the same thing. They contain the same ingredients, possibly minor variation in proportions though.

Question... would slowing down the reaction end up in making it actually dissolving more acrylic??? If so... you wouldn't want to use it on extruded material, (or lucite) correct???

Yep, which is why I always wondered why the market it for extruded
It's fine on extruded, just that you have to be a bit faster with it.
BTW Lucite does still make the "L" sheet, it's contuous cast, kinduva "tweener" between extruded and cell cast. Good material though and the solvent works nicely.

James

 

[miwoodar]

OK, so I picked up the materials and everything looks good. I had the edges cleaned up at a local plastics shop so I'm pretty much ready to go. The guy gave me a demonstration on using WO4 and showed me his pins/shims collection (for pins, he uses paper clips that have been partially unfolded with tips that have been pounded flat with a hammer - leaves a nice handle to pull them out with too). I also picked up a collection of drop material to practice on. I will have enough drop to make a 30x12x6 frag tank and a few small boxes.

I need a little advice on designing the overflow on the main tank. It will be external. The original idea was to cut out a 1x15 slot then install a grating to keep the critters out. I got the idea last night to just drill a bunch of holes instead. I figured I could lay out a nice pattern on tape, put it in place on the acrylic, and drill away. Is there any reason I shouldn't go this route? Do I need to get a bit designed for acrylic or will my wood bits work just the same?

 

[Chatouille]

if you are drilling that many holes.. I'd say yes, get an acrylic bit. They are ground at a different angle, so the grab isn't as bad. You could regrind a regular drill bit I guess to do the same. Go slow, and try not to generate too much heat at a time while drilling it.

Instead of just drilling straight out on the acrylic, make a template first so that you KNOW that the holes will be how you want them. Just tape down the template over the area how you want it, and drill.

Chris

 

[calvin415]

James, I've been using the Cyro calculator you mentioned in another post but curious if you have any Beta values when the L/H greatly exceeds 4? The spreadsheet defaults to the highest value (4) but I'm considering a shallow long tank and this calculator isn't going to work using a Beta value of .94

Example 12x12x96 (or longer) open top says it can be built out of 1/2"... No Way... I was thinking it would need be to be more like 1" for that long of a span... And even thicker for over 96 long. Thoughts? Ideas?

 

[miwoodar]

I've practiced a little and I feel like I'm almost ready to do the real thing. I do have two quick questions though - My seams look good but they are not perfect...

1) I don't have any bubbles in the seam itself, but the very edge has been generating a long, small line of tiny bubbles that begin to appear as it's drying. One joint in particular developed these bubbles on both the inner and outer edge. The edge being glued is square (not high sided in the middle). I think the bubbles are due to having to slide the vertical piece back into place after removing the pins (I have yet to pull out the pins without it shifting a touch). Yes? I want to re-make my jigs so they will run the entire length of the piece I'm gluing and I'm going to secure them to the horizontal plane (I didn't have double sided tape and have been making my joints without it). Is there anything else I should try?

2) My bottle tends to surge (very frustrating). It's a 25 guage needle. Cleaning the tip with a lighter hasn't helped. I haven't made the plunge to a 20 yet and was advised by the local shop not to until I have more experience. What if I went to a 22, might that help? Maybe ignore their advice and go all the way to the 20 as originally planned?

You're right - 30 seconds goes VERY fast. After making the run my first pins have been in for about a minute. The last pins have been in for about 30 seconds.

 

[Acrylics]

ooohh, I hate that calculator.... it's got a few flaws; best we've got but still flawed. I've contacted Cyro regarding the formula to no avail, even had their chief tech rep out to the shop to *show* them tanks built using their formula, again - no help
The multiplier for open tops should be 2.5 (minimum) rather than 1.5. A multiplier of 3 should yield pretty good results.
Use 1" for that tank, I've done it several times at 72" long and deflection was minimal at most.
When I have a little time, I'll look through my notes on Beta values. Hopefully today but dunno. FWIW, I used the formula and plotted a graph which works fine provided the other variables in the formula are corrected. If you follow the slope, comes out okay.
Forget the spreadsheet IMO. Plot the graph, take it from there.

James

 

[calvin415]

Thanks James, just so I understand your experience, did you build a 72 with 1" and still had deflection? If so going 96 should be even thicker. Don't think this is gonna be worth it... 12 wide suddenly become only 10 wide with acrylic taking up 2 iches and that sounds under-built... Looks like I'm gonna have to go with bracing.

 

[Chatouille]

miwoodar

Honestly, I couldn't use the 25 gauge needle with any consistency... it was difficult for me to just get a STEADY flow with it. I'm sure it all comes down to practice, but larger needle worked better for me. Just a quick question... what thickness are you practicing on, 1/4" ??? If so... remember your tank is being made out of material twice that thickness, so you'll need to flow more solvent out into that joint.

Here's MY understanding... **** James, please correct me if I'm wrong **** I believe the bubble are cause as the solvent evaporates from the joint. The solvent melts the acrylic, and when the pieces come together, the melted acrylic/solvent mix is pushed out of the joint. As the joint cures, that mix contracts back towards the joint. The acrylic starts to set before all of the solvent is evaporated, leaving those little bubbles.

Chris

 

[miwoodar]

Thanks Chris - I think I'm going to switch to a larger needle. It's really frustrating to suddenly have a 'gush' large enough to run the entire seam flood out in one little area.

Regarding the line of tiny edge bubbles...extrapolating from your idea above...maybe I'm letting the vertical pane drop a little too hard when I pull the pins and the acrylic/solvent mix is being splashed/pushed too far from the vertical pane? (too far and thus too thin to contract back properly.) Is this the idea you're going towards? James?

---edit---
BTW - I'm practicing on 1/2" drop material. I finished a small prop tank and I'm almost done with a top off container. Next will be the overflow box followed by the real thing. I'm happy enough with the edges on the top off container that I would feel successful if I did them as good on the tank itself. That said, I wouldn't mind them being perfect on the main tank either...

 

[H20ENG]

Is your needle getting clogged along the way, then clearing, causing the rush of solvent?

I always drag the needle slightly to avoid forcing any acrylic resin into the needle. Then, when finished, give a little squirt of solvent on the ground to be sure the nozzle is not clogged.

Also, do you have the squeeze technique down while holding the bottle, or are you letting it run out?

I agree with the #20 needle. I only ever use the 25 on very small projects or with the very runny WO3.

I wouldnt trust the hammered paperclips. #1, You couldnt be sure they were all the same thickness (not a huge deal, but...) and #2, my luck, I'd have little flakes of chrome from the clip in my joints.

 

[miwoodar]

Is your needle getting clogged along the way, then clearing, causing the rush of solvent?

I always drag the needle slightly to avoid forcing any acrylic resin into the needle. Then, when finished, give a little squirt of solvent on the ground to be sure the nozzle is not clogged.

Yes - I think it's getting clogged. I will pay more attention to dragging it at a backwards angle on my next try.

Also, do you have the squeeze technique down while holding the bottle, or are you letting it run out?

I've been shooting rather than letting it run out. As long as the needle remains unclogged, it works fine.

I agree with the #20 needle. I only ever use the 25 on very small projects or with the very runny WO3.

I think it's time for the larger needle too. I'm off to Walgreens to see what I can find.

I wouldnt trust the hammered paperclips. #1, You couldnt be sure they were all the same thickness (not a huge deal, but...) and #2, my luck, I'd have little flakes of chrome from the clip in my joints.

I made some but I abandoned the idea for the same fears. They didn't appear to be the same thickness no matter how hard I tried.

 

[miwoodar]

<a href=showthread.php?s=&postid=11723200#post11723200 target=_blank>Originally posted</a> by miwoodar


1) I don't have any bubbles in the seam itself, but the very edge has been generating a long, small line of tiny bubbles that begin to appear as it's drying. One joint in particular developed these bubbles on both the inner and outer edge. The edge being glued is square (not high sided in the middle). I think the bubbles are due to having to slide the vertical piece back into place after removing the pins (I have yet to pull out the pins without it shifting a touch). Yes? I want to re-make my jigs so they will run the entire length of the piece I'm gluing and I'm going to secure them to the horizontal plane (I didn't have double sided tape and have been making my joints without it). Is there anything else I should try?

Any other ideas on this? How important is it to have the exact correct amount of WO4 along the edge? Up above both Marc and James stated that 90 to 95% of the WO4 goes into the joint. I'm getting a small puddle of excess WO4 against the edge - I have a lot more than 5-10% of excess. When in doubt, I've been flooding the seam to ensure that it's definitely full. Might this also play into the line of very fine bubbles right along the edge I'm seeing? Once I see the WO4 reach from front to back on the particular spot I'm gluing, should I go ahead and move on?

 

[H20ENG]

mcmaster.com has a 20g needle bottle for about $5. I never could get good results with the syringe. I much prefer the bottle. Just have to master the squeeze to keep a vacuum in it til you are ready

 

[Acrylics]

<a href=showthread.php?s=&postid=11723373#post11723373 target=_blank>Originally posted</a> by calvin415
Thanks James, just so I understand your experience, did you build a 72 with 1" and still had deflection?

Please read again, I said deflection was "minimal at most" There was no noticeable deflection.

<a href=showthread.php?s=&postid=11724370#post11724370 target=_blank>Originally posted</a> by Chatouille
I believe the bubble are cause as the solvent evaporates from the joint. The solvent melts the acrylic, and when the pieces come together, the melted acrylic/solvent mix is pushed out of the joint. As the joint cures, that mix contracts back towards the joint. The acrylic starts to set before all of the solvent is evaporated, leaving those little bubbles.

Soooo, why doesn't this happen *every* time
One could easily make the argument that the "ooze" should set faster than the solvent/acrylic solution in the joint, thus creating a seal at the outside ofthe joint. And what factor could cause the ooze to contract back into the joint? Not knocking it BTW, it's plausible, but it should happen every time if this was the case, no?

<a href=showthread.php?s=&postid=11724499#post11724499 target=_blank>Originally posted</a> by miwoodar
Regarding the line of tiny edge bubbles...extrapolating from your idea above...maybe I'm letting the vertical pane drop a little too hard when I pull the pins and the acrylic/solvent mix is being splashed/pushed too far from the vertical pane? (too far and thus too thin to contract back properly.) Is this the idea you're going towards?

Following that line of reasoning, thicker acrylic would cause more of this issue than thinner material as thicker material is heavier, thus more downward force. But it doesn't work this way, I get similar joints in any material thickness that I work with, mostly 3/4" - 1.5".

BTW, got a pic of these joints?

There are alot of variables and I just don't think it comes down to one thing. Could be a combination of a number of things; dust, minor pitting in the machining, contraction of the joint (above), solvent, phisical properies of the material, moisture in the air and/or material, flexing of the cutter, warpage in material, soak time, and a bunch of other stuff, or a combination of factors.
FWIW, I've never seen a shop that could get it *perfect* 100% of the time so don't know that there's a single answer. To my knowledge, I've only built one *absolutely perfect* tank, as in I was completely satisfied with every joint. I keep trying as well
Another FWIW, I'd agree with others on doing a 20ga needle, it all I ever use and all I've used for the last 15 yrs or so.

H20ENG,
I'm still going down to the Dublin/San Ramon area at the end of next month for a bit of R&R, need anything?

James

ETA, all your page 20 are belong to us

 

[miwoodar]

Photos....good idea! I should have wiped it down before taking these shots. The middle of the seam looks great (too me) - the dust makes it look like there are a few bubbles - it's an illusion. The edges are what I would like to solve.

 

[Acrylics]

miwoodar,
Ah, that looks like a solvent/material issue to me, Plexi-Glas G?. Have you tried any other materials? Get some scrap of other brands, even some extruded and try those out (for practice of course). If you have the same issues, it's the juice. If you find a brand that works well for you, use that. I hate to put it that way but certain brands react differently to different solvents and techniques. It doesn't look like you are doing anything wrong, quite the contrary, you guys never cease to amaze me in how well you pick it up. Just that the materials don't seem to be working with you if that makes any sense. With "better" materials, you'd be doing *real* well. Hope you take that in the manner intended
If you can't find anything local, send me your addy and I'll send ya some scrap chucks o' stuff to practice with.

HTH,
James

 

[miwoodar]

I will pick up some scrap and play around (there are plenty of things I want to make anyways ). Might you be able to recommend a different type of solvent to pick up while I'm there? Yes, it's Plexi-Glas G.

A few of my runs have turned out perfect. Most look like the ones in the pics. FYI - I checked the room, it's around 60 degrees with <50% humidity.

 

[Chatouille]

Not knocking it BTW, it's plausible, but it should happen every time if this was the case, no?

The reason that I thought this, was due to playing around with weldon 16. For *me*, that stuff is a bubble making machine. And that's all weldon 16 is basically, correct? (weldon with acrylic shavings mixed into a gel) If I dab a glob of weldon 16 on a piece of acrylic... chances are it's gonna have bubbles for *me*, whereas if I just make a small puddle of weldon 4 on the acrylic, it dries clear. So much for that theory... lol :rollface:

Chris