Acrylic fabrication questions? I can help!

[110galreef]

Do you suggest prepping the areas to be glued w/ anything? This is some rather dusty & dirty acrylic I have had sitting around for about 2 yrs now. Also I did clean it w/ an acrylic spray cleaner prior to cutting as i wanted to minimize scratching as much of the protective paper had been removed.

 

[Acrylics]

I use denatured alcohol, always have, probably always will

James

 

[110galreef]

can that be picked up at a typical local store?

 

[TAB]

can that be picked up at a typical local store?

yep, most camping and or boating stores too as its used as a fuel for some stoves.

paint stores should also have it.

 

[Acrylics]

can that be picked up at a typical local store?

yep, any hardware store, also goes by shellac thinner. Don't soak the material in it at all - put some in a spray bottle and just a coupla spritzes on a soft cloth, then clean the edges with the cloth.

James

 

[vthondaboi]

Can you take a look below and confirm my suspicions...

3/8" G Acrylic with routed edges
Shim and pin method using Weld On 4
Acrylic has been sitting in the house at 70 degrees.

I let it soak approximately 40 second before pulling the pins. It was still pretty wet when I pulled the shims. I tend to have issues with edges that aren't surrounded by acrylic, like the ends shown here.

Do I need to let it soak longer before pulling the pins so the Weld On thickens up a bit more? Are these joints usuable?

Thanks in advance.

 

[Acrylics]

Can you take a look below and confirm my suspicions...

3/8" G Acrylic with routed edges
Shim and pin method using Weld On 4
Acrylic has been sitting in the house at 70 degrees.

I let it soak approximately 40 second before pulling the pins. It was still pretty wet when I pulled the shims. I tend to have issues with edges that aren't surrounded by acrylic, like the ends shown here.

Do I need to let it soak longer before pulling the pins so the Weld On thickens up a bit more? Are these joints usable?

I'm not familiar with "shim & pin method" but it appears the issue is one of two things; either you let it soak too long, or you just needed a shim between the work surface and acrylic.

IMO people let the joint soak too long and the joint begins to set before pulling the pins/wires. Also, when pulling your pins/wires, it's a good idea to release your clamps and allow the vertical piece to fall or squeeze the solution. Squeeze the work to the jig, release the clamp, and push the vertical piece down a little into the joint, thus squeezing the solvent solution a little.

When the work is still wet, gently pull up along the bottom (horizontal) piece with a fingernail, if you see movement, place a shim there. I use thin (.030") pieces of Lexan but a razor blade or anything thin will do.

Looks usable to me, when you glue the top/bottom, the solvent will usually migrate up a mm or 2 and should help.

And FWIW, your joints look better than those of most professional fabricators

For a couple of other little tips, visit this thread

HTH,
James

 

[110galreef]

James ,
another quick question. 36x 30 x 9.5 frag tank ...body & sides all 1/2. Need to make top euro brace. All I can vet local looks like is 1/4" & a 2x4 sheet. So I would need to cut strips to make top euro brace. Will this suffice? Or do I need to wait & order something? Alos if enuf how wide should the pieces b? 3".

Lastly is the 1/4" also thick enuf for an external overflow box that would be 24 x 4 x 5.5"

Thanks again

 

[110galreef]

I decided to order up some 3/8 acrylic for the top & overflow. Just dont like the feel of the 1/2"

What do you suggest or how does one polish up the edges to make them look nice, not the router only finish.

Also what do you recomend to round the edges on the eiuro brace with? Note I will be using 4 -2.5" pieces for the top, not a solid piece.

 

[110galreef]

weld on 16 as strong as weld on 4? Just thicker & different cure/set times?

 

[RokleM]

16 is a kind of gap filler. Use 3/4 for building a tank.

 

[110galreef]

made eurobrace top for frag tank out of 3/8 acrylic. I used 4 pieces to make the eurobrace. each is 2 3/4 wide. Glue the ends of all 4 pieces together 9weld on 4), then glued the top to the frag tank. The tank is 36 x 29 x 10. will the seams where the top is glued together be strong enuf or will the probably separate. Should i gule a piece of acrylic on the bottom side overlapping the seam or put a small triagle piece of acrylic in the corner where 2 pieces meet??

Also how do i radius the edge on the eurobrace so not so sharp. Just a light sanding?

How long to let all glue set before leak testing?

 

[Acrylics]

made eurobrace top for frag tank out of 3/8 acrylic. I used 4 pieces to make the eurobrace. each is 2 3/4 wide. Glue the ends of all 4 pieces together 9weld on 4), then glued the top to the frag tank. The tank is 36 x 29 x 10. will the seams where the top is glued together be strong enuf or will the probably separate. Should i gule a piece of acrylic on the bottom side overlapping the seam or put a small triagle piece of acrylic in the corner where 2 pieces meet??

Also how do i radius the edge on the eurobrace so not so sharp. Just a light sanding?

How long to let all glue set before leak testing?

You should put something on there to overlap the joint.
To soften the edge, use a sanding block or the side of a chisel and scrape it.
For water testing..as an average, joints are at 90-95% at 24-48 hours. Personally, I would wait at least 72 hours, if not longer. These are the things that cannot fail so IMO structural strength is paramount. Be patient

James

 

[Tampico96]

I recieved a large round tank from work last week. It was used in a trade show display to simulate a large oil tank in a tank farm complex. They used it for a week and then wanted it junked. I loaded it into my suv and it stayed in there 6-8 hours. Outside air temp near 0F. I carry it into the house and before I can set it down. The entire bottom fell off (delaminated? fell off as if it was never glued) There is no marks on either piece to even show evidence that it was ever glued. Clean as pictures of new builds I see on here. My questions are as follows.

1. should I use weldon 4 or 16 for this

2. this tank has no sides.... well just one per-se Any tricks for applying the Weldon and pin removal? ie. start on one side and work around, or work from 4 points to drop the entire pice down evenly..

3. Any prep I should do to the surface because of unseen residue?



I cant get any answers about the manufacture of the the tank. I know it held water for a week during the show with no leaks. I just never thought the bottom would drop out.

 

[SLO-STI]

James,

Is there anyway you can shed some light on to this question.

http://www.reefcentral.com/forums/showthread.php?t=1969668

Thanks in advance
Ryan

 

[Acrylics]

1. should I use weldon 4 or 16 for this

#4 won't work on this very well, should use 40 or 42.

2. this tank has no sides.... well just one per-se Any tricks for applying the Weldon and pin removal? ie. start on one side and work around, or work from 4 points to drop the entire pice down evenly..

See above

3. Any prep I should do to the surface because of unseen residue?

Yep, all has to be sanded or machined off.

I cant get any answers about the manufacture of the the tank. I know it held water for a week during the show with no leaks. I just never thought the bottom would drop out.

What is the actual diameter of the tube?
It's likely that the mfr of the tube is Reynolds Polymer as it looks to be larger than 28.635" diameter. Their tube is high mole weight so doesn't break down well to glue using solvents. The joints must be cast using 40/42. It's likely that the people who made it didn't know this so they used solvent and you see what happened. Freezing the tank just killed a "doomed from the start" joint. The bottom is under minimal pressure and can handle the short job it had, but for a good, permanent solution - the joint should be cast.

James

 

[Tampico96]

Thanks for your help James. You have helped so many people with builds. How many times did this thread split?

I did a little reading about 40/42 today at lunch. Looks like my only option is 40. way to small of a job to buy a gun to use the 42.

The instructions for 40 say that the glass needs to be annealed after machining prior to glueing. That does not seem possible in my small home workshop

http://www.regalplastics.net/pdf/PB40.pdf

It seems critical for a solid seam. What do you suggest on my next step? hunt down a local fabricator?

This tank was "built" by a set building company that specializes in trade shows in the chicago area. I'd bet that parts of this build were sub'd out to other contractors because the "build" company has no answers about anything.

I'll have to measure it again when I get home. I thought it was just under 36inches across. I cant remember if that was ID or OD. When I did a calc of its volume it was 60 some gallons.

I dont "need" another tank, but the shape of this was just too cool and I could not trash it.

 

[Acrylics]

Thanks for your help James. You have helped so many people with builds. How many times did this thread split?

Eek, I don't even know, maybe 3-4 splits?

I did a little reading about 40/42 today at lunch. Looks like my only option is 40. way to small of a job to buy a gun to use the 42.

Fair enough

The instructions for 40 say that the glass needs to be annealed after machining prior to glueing. That does not seem possible in my small home workshop

It's not necessary by any means. Annealing simply cures it to a stronger joint, but 2600psi is achieved without annealing and this number is on par with WO 4, and we will *never* see this type of pressure in the hobbyist environment - esp on this type of tank.
In a nutshell - don't worry about it - not critical
If you were casting a bunch of sheets together to make a 40' tank x 8-10' tall, yep, should be done. But on this thing, nah, no worries

I'll have to measure it again when I get home. I thought it was just under 36inches across. I cant remember if that was ID or OD. When I did a calc of its volume it was 60 some gallons.

Should be an OD, Reynolds is the only company in the world that makes a monolithic tube of this size and it should be 36" OD but they do allow for 1" tolerances so could actually measure about anything

Have fun with it
James

 

[110galreef]

You should put something on there to overlap the joint.

I glued in like 2.5" squares. Doesn't look to bad, but it's a frag tank not a DT!

To soften the edge, use a sanding block or the side of a chisel and scrape it.
James

what grit do you suggest

 

[SLO-STI]

James,

Can you help with one other question in my thread >> http://www.reefcentral.com/forums/showthread.php?t=1969668

Thanks
Ryan