clear acryllic edges

[Bopeep]

It's hard to get cut acrylic edges to be smooth and transparent like the factory edges, but my dad showed me a way to do it - thanks Dad! If you scrape the edges with a sharp razor blade over and over (and over) you can get them as smooth as you want to. Just keep the razor blade perpindicular to the edge and drag it along. Beats flame polishing if you ask me.

[Zephrant]

Good tip for small projects. If you have something large, you might want to try sanding.
I use a 1/4 sheet sander with 220/400/600 grit wet/dry paper. By the time you are done with the 600, it is smooth and has a little bit of shine. A few minutes with Novus #3 polish and a rag and it looks like glass.


Zeph

[Bopeep]

Is the polish good to use on edges that wll be bonded with Weld-on? I've heard this isn't a good idea. I used sandpaper also, but the razor blade gets the edge shiny. I'm not sure how smooth it has to be to get good bubble-less joints. I'll find out soon :)

[dattack]

What's Novus 3?
And is that the step you use Zephrant after you cut a piece of acrylic to glue?

[geshields]

Novus 3 is a heavy scratch remover for acrylic. It is like rubbing compound for your car. It is gritty. You can usually find it at any plastic store where they carry acrylic and the weld-on solvents.

I have never used sandpaper or the plastic polishes on the edges. I always flame polish the edges of my cast acrylic projects and I use a buffing wheel with Tripoli compound for the extruded projects. If you flame polish the extruded edges, they tend to burn and bubble more.


Greg

[geshields]

Dattack,

NEVER use NOVUS on the edges before you glue.

These are all done after the gluing process...

You can sand the edges before you glue to "clean up" the valleys but don't sand to a glass-like finish.

Greg

[Bopeep]

I used one of those little torch lighters on some scrap acrylic last night just to check it out. It got the edge very smooth, about the same qualities as the face of the sheet. Anybody know where to find info on flame polishing? Thanks.

[Zephrant]

Yep, what they said. :)

I use a MAAP cylinder with an auto-start torch head when I flame polish, but I currently only flame polish flanges. I I still hand polish tanks because I think it makes it look better, and does not take too much more time.


Zeph

[myreef]

Make sure you don't flame the edges before you glue them either.....you will not get a good glue joint and it can cause crazing....only flame after the pieces have been glued and let the glue cure for the recommended time.....or the glue will bubble out of the joint.

[Bopeep]

What's the best way to buff the edges?

[fixmgood]

Zephrant when you use wet/dry sandpaper,do you use it wet or dry?

[kanankeban]

Well, this question isn't about polishing...but I see some acrylic experienced people in this post...Zep, geshields, myreef
I'm just waiting for this question to be answered to go and buy a sheet of 1/2" acrylic for my new tank.
I will be building a 42"Lx18"Wx22"H acrylic tank...I have a doubt..If I build it without top braces, will it deflect? or should I add the top...if so..adding a one piece top with routed opening will add to my layout another sheet of acrylic...If I do the top with several strips of 2" of acrylic and a 4" center brace and glue them all together to form the top I just need one sheet..So..if I go this last way, will I be able to get a good looking strong bonds on the strips?
Regards...
Hector

[Cheapreef]

Originally posted by fixmgood
Zephrant when you use wet/dry sandpaper,do you use it wet or dry?
Use it wet, it makes a finer cut and it self cleans. No variations in scratch patterns, makes it easier to polish. I know this cause i'm a bodyman do it all the time.:)

Clinton

[geshields]

Kanankeban,

I would lay out the top piece with the individual strips and oversize it by 1/8" or so. Glue the strips together to get the shape of the top. Let the glue set-up for a few days, then glue the "top" onto the tank. Let the glue cure, then flush trim the "top" with the tank and it should be as strong as a whole top with the center routed out.

With acrylic, the glue joint is stronger than the acrylic itself as long as the edges to be glued together are perfect. If you have access to a jointer, I would definitely use it for the strips and then glue them together...

If you do it correctly, there will be very faint lines where the joints come together, but you will probably end up covering it with the canopy anyway...

Greg

[Zephrant]

Butt-joining two strips is difficult to do well, in acrylic, so I install a gussets.

Here is my first attempt at a gusset- Not too pretty, but strong. Later attempts got crystal clear joints, but this is a picture I already have posted. ;)

http://barraquatic.com/overflows_files/image006.jpg

Glue up the frame first, and scrape/sand the joint flat. Then I mask off the surrounding area to prevent drips from ruining the panel. Apply a bead of Weldon #16 to the gusset, and fit in in to place. Clamp gently for 1 minute, then increase the pressure to the clamps. With some practice, you learn how much Weldon to use, and when to clamp.

The joints come out perfectly clear when done right, and it is very strong. As a plus, if you let the gusset overlap the corner a little (as shown) it gives you a place to rest an Egg-crate cover, that is flush with the lid.

Zeph

[kanankeban]

With acrylic, the glue joint is stronger than the acrylic itself as long as the edges to be glued together are perfect. If you have access to a jointer

Thanks for the comments...the fact that the glue joint is stronger that acrylic itself gives me peace of mind...:D As I have a 8" JET Jointer I will go with the strip option...

Regards...
Hector

[Bopeep]

Anybody have info on buffing edges to be glued?

[Zephrant]

Yep, Don't buff before gluing. The gluing can craze up the joints if they have been buffed. It is better to trim and polish after gluing, and always wait at least 24-48 hours before flame polishing a glued edge.

Zeph

[criccio]

www.craftics.com has a great informative little book you can order for all your basic acrylic questions. Look under Products-Project Ideas-"Working with Acrylics.

[Grapevine]

Zephrant,

How to you flush trim the overhanging top with the tank? What tool do you use?

[Zephrant]

I use a router, with a "flush trim" bit. The bit has a bearing that rides on the panel while the cutters cut away anything that sticks past the bearing.

A roto-zip (with the same bit) will work in a pinch, too.

Without those tools, it is pretty hard though. Just cut it as close as you can, and glue it with a little overlap. Not as clean, but it is strong.

HTH-

Zeph