Acrylic fabrication questions? I can help!

[Acrylics]

Bond,

What are the materials? If the tube is acrylic as well as the base plate, then yes - you can use #16

mfinn,

Yep, extruded & cast can be glued together. Acrylite GP & FF are brand names of acrylic made by Cyro industries. Acrylic GP is a cell cast acrylic and FF is the extruded variety. Good quality materials.

HTH,

James

[bond007069]

yes they are both acrylic, thanks man

[Big Blue]

I have a question that I hope you can help me with.

I what is the best method when working with 1" cast acrylic as to getting a good glue joint that dose not shrink and suck in air. I have read the post about letting the glue sit and soften up the material before putting the pieces together but is that the only technique?

As you might be wondering I will be making a 450 gal tank soon and with my passed experiences with working with cast it can sometimes be a challenge, because it is such a dense material, to soften it up so you get fillet.

Will adding glacial ascetic acid 3% by volume to Weldon 4 help with this problem?

I have never herd of this before Acrylicman here at R.C. mentioned it but if you think that it would give me a better/stronger glue joint I wound be willing to give it a try. Does the acid slow the gluing time down? What are the pros/cons?
Also, if you know any theory behind why it is a good idea to add the acid it would be appreciated.

I might just have to work on my technique and leave the glue in the joint longer using the pin method before joining the pieces.

I appreciate any help that you can give in this matter being that I only have one shot at a $1500 tank.

[BlueBadger]

After Someone answers Big Blues question I also have a question.

I am in the planning stages for a 4'x4'x2' tall half cube. It was suggested I use 1/2" acyrlic and bracing by another online site. Bracing the top is not an issue, but how would you do it......Just eurobracing around the edge (i would think you would have to use thicker material) or a solid top with four holes in it (and use 1/2"). Any construction design suggestions would be appreciated, last think I want is a large tank bowing out alot...
Dan

[Acrylics]

Originally posted by Big Blue
I have a question that I hope you can help me with.

I what is the best method when working with 1" cast acrylic as to getting a good glue joint that dose not shrink and suck in air. I have read the post about letting the glue sit and soften up the material before putting the pieces together but is that the only technique?

No, you can cast the joint as well but this does take some practice and another invesment of the required tools (either Weld-on 42 applicator gun, centrifuge, and/or vacuum pump for removing air).

As you might be wondering I will be making a 450 gal tank soon and with my passed experiences with working with cast it can sometimes be a challenge, because it is such a dense material, to soften it up so you get fillet.

With a good solvent - this should take 15-20 seconds of actual "soak" time.

Will adding glacial ascetic acid 3% by volume to Weldon 4 help with this problem?

Some, yes.

I have never herd of this before Acrylicman here at R.C. mentioned it but if you think that it would give me a better/stronger glue joint I wound be willing to give it a try. Does the acid slow the gluing time down?

Acid, by it's very nature does not evaporate readily, so by adding a little, you will in effect slow down the reaction time of the solvent.
MCBond and Weld-on #5 are both made from methylene chloride and acetic acid so it's nothing new

What are the pros/cons?

Pros are that it slows down the reaction time and it helps solvent flow better into the joint. The downside is that the joint can change (kinda) for a coupla hours after gluing. The only other downside is if you use too much acid, the joint can become grainy looking.

Also, if you know any theory behind why it is a good idea to add the acid it would be appreciated.

I might just have to work on my technique and leave the glue in the joint longer using the pin method before joining the pieces.

I appreciate any help that you can give in this matter being that I only have one shot at a $1500 tank.

Understood, you'd be well advised to practice quite a bit, be absolutely certain you are using a good material such as Polycast, and maybe try a coupla different solvents. MCBond is a great, pre-mixed solvent.

Originally posted by BlueBadger
I am in the planning stages for a 4'x4'x2' tall half cube. It was suggested I use 1/2" acyrlic and bracing by another online site. Bracing the top is not an issue, but how would you do it......Just eurobracing around the edge (i would think you would have to use thicker material) or a solid top with four holes in it (and use 1/2").

If you want to use the 1/2", the top should be a 4 x 4' piece and machine the access holes out of it by either a table mounted router or have it done for you professionally. Many shops will do it this way, some will use lasers, and some will use a CNC router.
Whichever method you choose, be sure to use large radii in the corners of the cutouts to distribute stress better, 2" radius or so would be great.
If you want to eurobrace it, thicker material is required for the sides and top, if you want to go this route lemme know

I posted a thread call "DIY tank, step by step" or something to this effect some time ago and it shows how to make the top cutouts if doing it at home. Just search for DIY in the title and me as the author.

HTH,

James

[Biodragen]

FWIW
If you can get a hold of small scraps of that thickness--it may be worth practicing with it first before going with the live materials.

This way you get a better feel for the thicker stuff.
Small investment this way.

[Big Blue]

Thanks for such a great reply Acrylics! That helps me out a lot. Weldon 42 you say, ah, sounds like something new to try.

[Rich_Lucas]

I am looking to make a sump that will be about 13 inches tall, 14 inches wide, and 36 inches long. What thickness of acrylic should I be looking at. Also what is a good price for acrylic? I went to a local plastics place who quoted me $14.48 per square foot for 3/8 thick. Is this around a normal price? It seems kinda expensive to me.

Thanks.

[jcaulley]

Would 1/8" wall cast acrylic tubing be ok for a 28" tall 4.5" outside diameter protein skimmer?

[Big Blue]

$14.48 per square foot for 3/8 thick

What a ripoff. Don't buy it. In the Bay Area if your paying more then $4.75 a square foot for 3/8 your paying to much. Shop around and look in your Yellow Pages.

[Acrylics]

Rich,

BigBlue has it right on, just be sure to not to skimp on the material, get good material such as Acrylite, Plexi-Glas G, or Polycast (best IMO)

Jcaulley,

1/8" wall tube will be fine for that. Due to it's shape, tube inherently distributes stress better than any other shape so on tube we can use thinner wall thicknesses than with squares, etc.

James

[SUMMERS]

Heads up to anyone looking to replace or purchase a spiral flush trim bit. MLCS has them on sale. They are regulary $80 or so and are on sale for $60

http://www.mlcswoodworking.com/shops...iral_up_anchor

[adrinal]

One is an upcut and the other a down cut. Is the berring at the end on both of them and just the intended direction of the chips are different?

Perhaps a better question is... what is up down cut?

[kgross]

You are correct adrinal, the direction the chips are moved is what is different between the up cut and down cut. the up cut drags teh chips up to the router (upright usuages not upside down on router table), and the down cut pushes the chips down.

Kim

[adrinal]

shoot, I sure was hoping it would change the position of the bering as well It sure would be nice to have a berring on the other side for my router table. It would make making overflows much nicer.

[Bowman]

Hey all They do make bits with the bearing on the oppsite end of the router bit, they are just not spiral cut bits. Browse through the many online catalog sites or check at a local woodworking store. Sears, HomeDepot, Lowes,etc may have what your looking for as well.

HTH

John

[Acrylics]

Adrinal,

The bits you are referring to are generally called "pattern bits" where the bearing is on the shank side of the bit. They generally have a collar with set screw to remove & replace the bearings when needed. Due to this, many spiral cutters can be converted, so to speak, into pattern bits.

James

[adrinal]

Interesting, Thanks!
I will deffinatly give it a try.

[BtheReef]

Ok, I have been trying to make some acrylic hangers for my maxi-jets and have run into a problem right off the bat.

I'm attempting to get a piece of acrylic that is about 1.25" wide from a sheet that is 12x10". First, I scored the line and tried breaking it off the larger sheet, but ended up breaking it lengthwise. I believe this was because of eneven pressure using my hands to break while holding the sheet over a dow rod.

Next, I tried cutting the section off. I got the piece I needes, but with way too much chipping along the edge. I really can't get a table saw or other expensive tool.

So, any suggestions on how I can get a thin lenght of acrylic off a larger sheet? I'm not sure what I'm doing wrong.

Thanks

[BtheReef]

Ok, I have been trying to make some acrylic hangers for my maxi-jets and have run into a problem right off the bat.

I'm attempting to get a piece of acrylic that is about 1.25" wide from a sheet that is 12x10". First, I scored the line and tried breaking it off the larger sheet, but ended up breaking it lengthwise. I believe this was because of eneven pressure using my hands to break while holding the sheet over a dow rod.

Next, I tried cutting the section off. I got the piece I needes, but with way too much chipping along the edge. I really can't get a table saw or other expensive tool.

So, any suggestions on how I can get a thin lenght of acrylic off a larger sheet? I'm not sure what I'm doing wrong.

Thanks

[BtheReef]

stoopid internet... sorry for double post

[Ehydo]

Try scoring it more and applying even pressure when breaking it. Look for a place where you can apply even pressure like a door jamb.

[Vincerama2]

If you have a hand held "jigsaw" (sometimes called sabersaw) you can buy a $5 plastic cutting blade (actually you get two for that price, one for 1/8 plastic and one for thicker plastic) that works really well without chipping the acrylic. You can scrape the edge "clean" after with an edge scraper OR a carbide router bit (you can scrape with the bit itself, you don't need the router).

V

[juststartingout]

Hi Acrylics, awhile ago I had asked you about the thickeness necessary for a sump I am going to build. It will be 72x36x20, I just bought some acrylic sheet today, finally:-). Make a long story short, they were out of Acrylite GP, so I bought Plexiglas G. I read that Plexiglas G is made in Mexico and it is actually .472, instead of .500. Will this be alright to use? I thought in an earlier post that someone said to stay away from import materials. Thanks for your time!

[m23]

You'll be fine, Plexiglas G is decent. Don't let the variance in thickness bother you, some import is made to metric mesurements. I've seen sheets of 1" come in at 3/4"! I like Rohm and Haas it smells like blueberrys when you machine it.