Acrylic fabrication questions? I can help!

[Acrylics]

I generally don't use 40/42 for much other than making acrylic panels longer than 10 feet or for "sealing" joints where you can't actually see the joint - such as gluing black on black, like gluing a black overflow to a black back. Otherwise, I have very little purpose for it. I use solvent for nearly everything up to 2.5" acrylic. For the most part, getting a good edge on material above that requires a different type of tooling and is extremely difficult to avoid flexing of the cutters.

In most shops, they may use 40/42 for the vertical panes but still solvent weld the tops and bottoms.

Yes, spacers are commonly used for many applications where you're gluing uprights, such as ends of the tank to the front, but I think that looks crappy. When making longer panels, there's a bit more to it as the spacers can't be there. You fill the void with 40/42 and then gently squeeze the joint as it's curing to offset the shrinkage of the resin as it cures.

As for making a video, perhaps down the road. I've never posted anything on you-tube or similar and whenever I've tried posting one on Photobucket, they always remove it for some reason. But I may try the you-tube thing before long

HTH,
James

 

[Westcoastindia]

Thanks for your inputs.
As comparing the tech specs of solvent weld seams to the two part reactive cement. The two part has better ts and other specs. If done precisely how long do you think solvent welded seams last?
Solvent welding 2.5in is a big achievement in itself but still would be highly subject to rejection as you might get some bubbles in there. And also very difficult to maintain consistency with builds . you might have had a fair share of rotten seams before you mastered this art it seems.
As far as tooling is considered nothing beats water jet in terms of accute cuts. Water jetting has its own benefits such as it does not exert pressure on the material as the force is downward. Hence zeros in the chances of material stress. It saves the annealing process.
For the backlash of nozzle I'd suggest one would put a plywood or Styrofoam. Try at your own risk.
James could you shed more lights on how do you weld such thick seams.
You the man.

 

[Acrylics]

Thanks for your inputs.
As comparing the tech specs of solvent weld seams to the two part reactive cement. The two part has better ts and other specs.

Not *really* while they may claim whatever thousands of PSI it can handle, without annealing afterwards, it's pretty comparable to solvents. And let's be honest, your tank joints will *never* see above 2500PSI. Furthermore, their claimed joint strength has *nothing* to do with how well the stuff sticks to the materials to be bonded. Try casting joints on cross linked acrylic or even AR coated acrylic. The "bond area" may have good strength, but the entire joint will simply fall off the bonded material. With solvent, it can be seen quite readily.

If done precisely how long do you think solvent welded seams last?

Dunno, recently saw a 10' long x 6' tall tank I built back in the 90s and it still looks pretty new.

Selevent welding 2.5in is a big achievement in itself but still would be highly subject to rejection as you might get some bubbles in there. And also very difficult to maintain consistency with builds.

same thing happens with cast joints. I've seen a number of tanks with cast joints that could have been rejected. Not worth it to me.. There is a place for cast joints, but IMO not appropriate for 99.99% of applications.

As for water jets; I don't like the edges they leave. I can do better with a handheld router and a well made router table does even better..

James

 

[vertigo01]

As far as tooling is considered nothing beats water jet in terms of accute cuts. Water jetting has its own benefits such as it does not exert pressure on the material as the force is downward. Hence zeros in the chances of material stress. It saves the annealing process.
For the backlash of nozzle I'd suggest one would put a plywood or Styrofoam. Try at your own risk.
James could you shed more lights on how do you weld such thick seams.
You the man.

Actually, with water jet's, it is a controlled erosion of material. You are correct that water jet's can and will provide a much more accurate cut. =/- .005 also providing a faster cut than a router.
That being said the edges will be frosted and will require polishing or touching up with a router.
If you have ever had to deal with a water jet tank full of styrofoam piece part's, you wouldn't do it a second time.:facepalm:

Water Jet's do have their place but not in a high rate acrylic manufacturing business.
The risks far outweigh the rewards. This coming from someone who manages 3 water jets on a daily basis.

 

[Westcoastindia]

James
Could you please elaborate on your routing technique and router table. I have had some difficulties with the router in the past. Routing such thick acrylic would also require router with more torque. Also enlighten on the router speed and specs. A picture would speak a thousand words.
How do you weld such long seems for instance say 9'. The most difficult part would be the bottom and the top. Pin method is not feasible for such long seams hence to rely only on the machined tolerance of the edges would be next to impossible.
What solvent do you use? For long seams wo3or 4?
None of the scigirip or other products are avail in India.
What I do is I procure all the raw materials and make my own solvent. The approx mix value is stated in msds(material safety and data sheet).
Same that I did to substitute for wo 40.
Sigma Aldrich mma inhibited by mehq less or equal to 30 ppm. I remove the inhibitor before the catalyst. With the initiator or activator Sigma aldrich luperox afr40, benzoyl peroxide solution. Contain benzoyl peroxide with dibutly phalatate as a plasticizer. Benzoyl peroxide comes in a powdered form and is subjected to moisture somewhere around 40 percent. Hence to make it anhydrous it is mixed with the plasticizer dibutly phalatate. This gets very crazy, since now Sigma aldrich India has discontinued the initiator from their range of supply.

 

[Westcoastindia]

Vertigo
I thought a little rough edge is better for adhesion for solvent welds then a complete polished one.
You are right about the Styrofoam and the production at value of water jetting it don't seem feasible.

 

[Westcoastindia]

James
I'm looking for an answer.
Would you please share your views?

 

[vertigo01]

Vertigo
I thought a little rough edge is better for adhesion for solvent welds then a complete polished one.
You are right about the Styrofoam and the production at value of water jetting it don't seem feasible.

The problem, is that the edges will be frosted ( think frosted glass )making the seams much more visible without polishing.
Also the very top and bottom outside edge of the cut would be frosted as well necessitating polishing. The idea of a 1/32" wide frosted frame around the whole piece is visually unappealing, at least to me.

 

[veloboy]

Although I've consulted and followed this and other acrylic fabrication threads on RC for years I've rarely posted. Wanted to thank everyone that has contributed particularly James and Turbo. Your experience and insight is priceless.

Quick question- when you have large sections of material (acrylic) that needs to be removed do you remove material first with a blade and then route the final pass or do you typically let the router bit do all the work? For example when fabricating a eurobrace top the inside acrylic section is removed- do you remove most of that material first with saw and then make final pass with router bit or just let the router bit do all the work removing all that material?

 

[Westcoastindia]

Vertigo
The seams where it's welded using solvent would have a frosted LOOK?
The materials adjoining the seams would melt and leave a clear finish I think. Outside edges can be flame polished.

 

[mntbiker2008]

So Ive done some searching but not finding the answers I need. I am trying to make a little frag shelf that I can stick on the side of my tank with suction cups. I have a few questions:

1: what is the best way to form a 90 degree angle so I am only using one piece of plexi? oven, heat gun? What temp/ how long/ what can I use to elevate the piece off the grates?

2: How can I drill the holes for the frag plugs without cracking the plexi? Every time I have tried the sheet just snapped.


Thank you

 

[vertigo01]

Vertigo
The seams where it's welded using solvent would have a frosted LOOK?
The materials adjoining the seams would melt and leave a clear finish I think. Outside edges can be flame polished.

Yes. It's the nature of water jet cutting. Although the water/abrasive stream is concentrated in a 40 thou diameter stream, with a large percentage being used to erode the material, there is still a small portion that escapes causing the frosting.
Whether it can or can't be flame polished out, I have no idea, never tried it to be honest.

 

[rfgonzo]

So Ive done some searching but not finding the answers I need. I am trying to make a little frag shelf that I can stick on the side of my tank with suction cups. I have a few questions:

1: what is the best way to form a 90 degree angle so I am only using one piece of plexi? oven, heat gun? What temp/ how long/ what can I use to elevate the piece off the grates?

2: How can I drill the holes for the frag plugs without cracking the plexi? Every time I have tried the sheet just snapped.


Thank you

1, Depends how thick your Acrylic is, but I will assume it's under 1/4. A good heat gun will work fine.

2, They make drill bits for plastic, 1/2'' will work for frag plugs.

 

[mntbiker2008]

1, Depends how thick your Acrylic is, but I will assume it's under 1/4. A good heat gun will work fine.

2, They make drill bits for plastic, 1/2'' will work for frag plugs.

Thank you!
Yes, it is under 1/4" . I will have to look for those. Had no idea they made them.

 

[easttexas]

James
Could you please elaborate on your routing technique and router table. I have had some difficulties with the router in the past. Routing such thick acrylic would also require router with more torque. Also enlighten on the router speed and specs. A picture would speak a thousand words.
How do you weld such long seems for instance say 9'. The most difficult part would be the bottom and the top. Pin method is not feasible for such long seams hence to rely only on the machined tolerance of the edges would be next to impossible.
What solvent do you use? For long seams wo3or 4?
None of the scigirip or other products are avail in India.
What I do is I procure all the raw materials and make my own solvent. The approx mix value is stated in msds(material safety and data sheet).
Same that I did to substitute for wo 40.
Sigma Aldrich mma inhibited by mehq less or equal to 30 ppm. I remove the inhibitor before the catalyst. With the initiator or activator Sigma aldrich luperox afr40, benzoyl peroxide solution. Contain benzoyl peroxide with dibutly phalatate as a plasticizer. Benzoyl peroxide comes in a powdered form and is subjected to moisture somewhere around 40 percent. Hence to make it anhydrous it is mixed with the plasticizer dibutly phalatate. This gets very crazy, since now Sigma aldrich India has discontinued the initiator from their range of supply.

The method I used for routing was as follows. I could not find one of those expensive spiral cut router bits like was discussed here before, but use a high quality 1/2"x 2 1/2" (I think) double fluted bit. I personally have a 4x8 work table I build many many years ago, and I mounted a 3 1/2 HP router under it with a hole for the bit to go thru. This makes working on large pieces much easier than a little router table. I cut all my pieces on my table saw to about a 1/4" over sized. I then set my fence, not right at the bit like a jointer (they can make things unsquare) but at the distance of the piece I'm trying to trim plus about an 1/8th. This lets me get a perfectly parallel and smooth first side. use feather boards to push the work piece into the fence!, learned that the hard way. I cut every piece that I have that size all at the same time, then move my fence the 1/8" to do all the other sides. The ends are typically routed off after bonding if you planed well. As to your long seam question. The longest I've done has been 16 linear feet, and it took my brother and 2 of my boys along with a couple timers (phones) my brother and I started in the midle of one ling side with the solvent bottles, and when the timer went off, I had the teenagers start pulling the pins at the same rate we were going, I had to coach them while doing my part at the same time, but it came out flawless. I did have to adjust some of the shims to get rid of some small bubbles, but thats all it took. It was about 55 out in my shop and we waited about 20 seconds if I remember right.

As to the routing the top (do this before welding on the bottom) I used some double sided tape and 1X wood to make the outline I wanted, used a hole saw to make the radius'as I wanted out of some scrap, then cut those into 1/4ers and taped them in, then used a top bearing flush bit to do the whole thing. I've done this on 1/2 and 3/4" so I know you don't have to saw it first. caution, these edges are so square they are sharp, I ran an appropriate sized round over bit myself on some pieces, and just use and old fashioned wood scraper on others.

This was my sump

Got kinda long, but its pretty much just like high end cabinetry work

Mark

 

[Westcoastindia]

East Texas,
Thanks for your inputs.
I'll do some trials and post here later.
Could you share some more pics from your build?

 

[easttexas]

Got lots of pictures on my build tread, it never really got much attention so I didn't really keep up with it after the build was done. I was rather proud of the build though, and other than a couple Chinese pump failures and an aipstasia out break even though I dipped everything and started with dry rock, it has been pretty successful.

http://www.reefcentral.com/forums/showthread.php?t=2399652

 

[Westcoastindia]

Easty
Man you're awesome.
I read the entire thread. Your attention to detail and dedication is much appreciated.
I'm a big fan of jeeps. Your jeep builds are far more sexy then any thing else.

 

[Acrylics]

James
Could you please elaborate on your routing technique and router table. I have had some difficulties with the router in the past. Routing such thick acrylic would also require router with more torque. Also enlighten on the router speed and specs. A picture would speak a thousand words.

Do a search for threads with me as the author "DIY tank, step by step" or something to this effect. I go through much of this stuff in there

How do you weld such long seems for instance say 9'. The most difficult part would be the bottom and the top. Pin method is not feasible for such long seams hence to rely only on the machined tolerance of the edges would be next to impossible.

You're basing this sentence on a premise to which I do not subscribe. Who says it's not feasible? I do it all the time. The pic below is a single long run of 1.5" and 2.5" material, done with solvent in a single run, length is 10' and height is 6'. BTW, I built this in the 90s and this pic was taken last year. A closer view is in my album. So to think that solvent joints can't hold up over time is simply not accurate.

What solvent do you use? For long seams wo3or 4?

Neither, I make my own based on the material, the job, and the weather.

None of the scigirip or other products are avail in India.

None are necessary.. IMO keep it simple...

James

 

[AZRippster]

Quick question that I'm sure has been addressed but finding it is proving tougher than expected, at least a solid answer.

What is the best bit, tool, technique, etc. to drill a hole in an acrylic tube. I've used various methods through the years with varying results. In plate, I like Forstner bits or drilling a small pilot hole for a larger hole and then routing with a template on a router table. This obviously doesn't work on a tube. Stepper bits also work well, but the stepping is dependent upon the material thickness and once again, not so great on a tube. I need a 1 1/4" hole in a 6" acrylic tube. Any advice would we awesomely appreciated.

Thanks!