Backlit BYOAC logo out of translucent casting.

[Donkey_Kong]

Hello everyone.

I just started the process for a BYOAC logo that I plan to backlight. I have already done this with the GameRoom Magazine logo that my wife carved.

I'm hoping for a few pointers on constructing a round box for this...as well as lighting to be used. I appreciate any help with that.

Here are some photos of the cast that I just poured about 15 minutes ago. It will be set hard enough to handle in about 16 hours.










BELOW is the one I did with the GameRoom casting. You see my challenge is going from rectangular to round. So the question will be this:

How many BYOAC members will it take to teach a donkey to build a round box!!?? How long will it take for all the information to sink into his thick headed skull? Will the Donkey be able to stay away from throwing barrels and chasing the princess long enough to make it all work?








I realize I could make a square box for the BYOAC casting and back light it yada yada. I don't want to do that though...I want to go round. I'm really just looking for some wood types that you have used on your projects and that have worked well.






 

[Havok]

Why not a solid round casting to fit the translucent one into?

[mountain]

Is the box to hold the plaster to form a round mold? If you have a circle cutting jig for your router you could cut out 2- 3 rings out of MDF and glue them together. Then attach them to a base.

[Donkey_Kong]

Havok-Not a bad idea, I suppose I could use some casting but I think I'm going to go the wood route to save $$. Casting material is $moucho denaro$.


Mountain- I'm liking that idea. Now to make a jig, & I just remembered that the cast isn't perfectly round. Improvisation there will be putty of some sort though. The GameRoom sign has it's share of it.     

Thanks guys.

[HaRuMaN]

What did you backlight the GameRoom sign with?  Also, did you scuff the back of the material to diffuse the light coming through? 

[Kaytrim]

If you want hardwood like you did with the GameRoom logo then I would go with the circle cutting jug and router that mountain suggested.  Otherwise you could fabricate a nice shape with MDF and make a mold.

TTFN
Kaytrim

** edit this is one fast paced thread. didn't see that you already shot down the mold option.  You could still go with MDF, it'll still be cheaper than hardwood.

[SavannahLion]

My father used to steam bend wood. The radius might be too tight for thick pieces. The banisters at work have some very tight curves and they appear to be very thin strips of wood laminated together into the curves.

Sadly, I never had the opportunity to learn the technique first hand from my father. 

[Kaytrim]

I did a steam bend once on a 1/4" piece of popular.  Turned out rather well and it would be about the same radius as what you are looking there DK.  If you want to go that route take and cut a piece of plywood the same size and shape that you want for the box.  Cut a few holes about 2-4 inches from the edge.  These holes are for your clamps while the bend is in process.

Steam your wood for a while, the site that SavannahLion linked to is a good one.  When you take it out clamp one end to the form and start bending it around adding the other clamps as you go round.  It might be a good idea to use 2 or three thinner pieces instead of trying to bend one thick piece.  This way you can make a laminate which will be much stronger and hold the shape better.  After you have your first piece in place undo one of the clamps in the middle.  Start bending your second piece there.  I would recommend using Tightbond III glue to join the two pieces of wood together as you bend the second piece around the first.  Work your way around undoing one clamp, bend the second piece and re-clamp adding the glue as you go.  Tightbond III is waterproof and makes a real strong bond.  This way once the glue cures you don't have to worry about the bond coming undone if it gets wet.  Keep adding boards until you get the desired thickness.

One other thing.  Make your pieces wider than what your final width will be.  This way you don't have to worry about lining up the two pieces as you bend them.  You can use a belt sander to take the wood down to the final width.


Let us know what you end up doing.

TTFN
Kaytrim

** edit added pic for clarification...

[bfauska]

There are bendable wood products available.  I am only aware of the slang names we use for them in theater and one brand name. 

Kerfcore is a product similar to MDF, it is available in various thickness and the back side of it is grooved.  It gets it's name from a process of using the material removed by the saw (the kerf) to allow you to bend wood.  The finish is smooth and paint able like MDF.  To make your "box" for your back lit sign, you would copy the shape of the casting out of plywood (perhaps a router with a flush trim bit) and then attach the kerfcore around the perimeter. 

The other product is what we call "wiggle wood" or bender board.  Searching on the internet seems to show some products for making concrete forms, but they are a different product.  This product is like plywood with all the layers running the same way.  It is very bendy depending on the thickness.  I would suggest going with a few layers of 1/8" because it has the smoothest face, but still not as nice as the kerfcore.  The construction process would be about the same as the kerfcore, but if you did multiple layers you would want to do one layer and then use a paint brush or roller to apply a thin layer of wood glue and apply a second layer.

This info is probably a little vague and the products aren't super cheap.  The main cost problem would be that you would likely have to buy a full 4'x8' sheet and for this project you'd probably only use a small portion of that.

If you have any lumber stores around you might give them a call and ask for either of the products above, or tell them roughly what you are doing and see if they know of another product.  And I mean Lumber store, not Home Depot or Lowes.  I they do have the product they may ask if you want "barrel" or "column" roll, this is in reference to which direction the sheet bends easiest.  Barrel is made so that if you rolled it you would have a cylinder that was 4' tall with a circumference of 8', column would be 8' tall with a circumference of 4'.

If I am being confusing or vague let me know and I'll try to clairify.

[SavannahLion]

The other product is what we call "wiggle wood" or bender board.  Searching on the internet seems to show some products for making concrete forms, but they are a different product.

I don't recall the name either but I know what you're talking about. When I used to work for the theater, we used it to make stage props like the bow of a ship. I think we called it "flexible plywood".

[theCoder]

Way back in highschool I made a skateboard deck using the bent wood processes described above.  It had 10 layers of 1/16" thick wood.  For strength, each sheet was rotated 90 degrees, but I don't think you will need to do this.  You can make some pretty wicked shapes with this process, and depending on the glue and clamps, can be very strong.  That skateboard lasted a long time.

To cover the laminate edge, I'd recommend making a hard wood strip to go around the perimeter, cut to fit the edges of the casting.

To cover up the seam on the perimeter (where the last sheet meets up) you could put splines running from front to back.  You would only need one, but for aesthetics, you might want 4, 8, or more.  It might end up looking like a barrel this way.

HarumaN mentioned scuffing up the back to diffuse the light.  You might also consider using a piece of textured glass.  It might not be cost effective, but it would be consistent.

Cool project.  I'm doing a lot of experiments with lighting right now myself.  Lots of fun.

A couple of questions: 

How did you make the mold?  Did your wife carve a master, then rubber mold from that?

What material did you use for the casting?  I presume it is pretty toxic to the nose?

Did you do anything special to avoid/remove air bubbles?

Good luck.

[Kaytrim]

To cover up the seam on the perimeter (where the last sheet meets up) you could put splines running from front to back.  You would only need one, but for aesthetics, you might want 4, 8, or more.  It might end up looking like a barrel this way.

That gives me an idea.  Use the hardwood in blocks and glue them around the casting.  Then use a piece of kerfboard on the inside behind the casting to stop any light from escaping between the blocks.  This could give the 'box' a real barrel look.

TTFN
Kaytrim

[Donkey_Kong]

Great ideas guys. Awesome! I will give it a shot and see what happens.

Coder: Funny you mention the toxicity. There is no apparent fumes what-so-ever when mixing this stuff. However, my wife realized by reading your post that this stuff is what is causing her face to break out in a major rash and swelling. She realized that this happened both times she has been around me pouring this stuff.

    

It is toxic...very toxic!

[bfauska]

If you bevel the edges of the hardwood pieces you could make a regular polygon of whatever number of sides you want (set according to the angle) and then sand to a rounded shape.  This way you wouldn't actually need any kerfcore inside because you could make the joints tight.  The math for the size of pieces would be an important factor to make the circle the right size, but it's totally doable, and the angle of the cuts is really simple, I would be you could get a smooth enough circle out of a 36-agon so beveling each edge of the boards 5 degrees would work.

[SodaPopinksi]

Wow that looks sweet, can't wait to see it lit up 

[jfunk]

Would you be able to do something like this thread with this process?

[Donkey_Kong]

Time to back pedal just a bit. The material didn't setup and was all gooey. It made a good mess in the mold. I washed a lot of it out with soap and water. I got most of it, but not all. Any ideas on what I can do to clean this out of the Silicone mold.

[Kaytrim]

If the stuff you are using is a two part deal add a bit of the hardener to the mold.  See if what is left will setup and then you should be able to crack it out by bending the mold.

Good Luck,
Kaytrim

[Donkey_Kong]

Thanks Keytrim.  I already de-molded and gave up on this cast as it was a disaster from the beggining. There is no saving it. I know I can get it right, I just have to try again and mix better and more accurately.

I was wondering what kind of chemicals I can use to clean up my mold as it has some remnants of the sticky un-hardened casting material. Also, what I might stay away from. I could call my suppliers tech support on Monday as well.

[Kaytrim]

I was referring to the remnants.  Take a brush with hardener and coat the what is left to see if it will harden and come out of the mold.  Calling tech support is a good idea as well.

TTFN
Kaytrim