Currently its impossible as far as I know. There is no way to 'place' the sign on the chest, this requires that we are able to always 'use' whats in our currently selected hot bar. This is done on the PC by 'sneaking', and last I checked this mechanic was not implemented on the 360. Basically the mechanic of 'sneaking' will use whats in your hand on any object with an inventory rather then accessing its gui. For example sneaking and clicking on a furnace with dirt or a torch in your hand will place the dirt or torch. The same mechanic is used to place signs on objects with inventory or gui.
This mechanic will have to arrive in the next update or two with some of the new things coming, however 4J may implement a different method of handling such mechanics.
Or, another way to look at it is, each individual item takes up a block.
A sign takes up a block. (Though there's a transparent part and the sign is 'thin', it still takes up a whole block).
A chest takes up a block.
Two blocks can't occupy the same space.
You can put a sign in front of chest, and I believe you can put one on the wall above and behind a chest (and it still opens), but you can't put a sign ON a chest.
EDIT: Think ladder. It looks like a ladder is placed 'on' a block, but it still takes up a whole block. That's why lava blades work like they do.
Try Denfros idea; make the chest unable to open by putting a solid block on top of it. It works with item frames and I can confirm that but I haven't tried signs. Don't see why that wouldn't work.
How?
I just tried it myself to double check and I couldn't. What I didn't try was putting a block (i.e., dirt) on top of the chest. Now that may work (I guess turning a chest into a 'normal' block).
But I gotta ask:
1- What good is a chest that won't open??????
2- Why does that sign have to be actually on a chest?
The block on top keeps the chest from opening, treating it like a normal block, and then you can place signs and item frames on the chest itself. You can remove the block that keeps the chest from opening and use the chest as normal with whatever you put on the chest still there. It can get difficult to work with because it changes the chests' "use" box a little. You have to click the chest to open it so you have to find a spot to click on around the sign or item frame.
A double chest would but I have mine (and I can't put a pic up right now) arranged length-wise recessed in the wall so even with a double chest I can only open on one side. So putting an item frame on that makes it so hard to open the chest...
Just place a solid block, such as dirt, on top of the chest so it can't open, you can then place the signs however you want
Very clever, but its still only a 'half-fix' so to speak, hopefully the sneak/use mechanic makes its way in the next feature update.I personally don't like to use item frames as they count as entites and use if its anything like the PC counterpart is rather hard on rendering and can seriously drop the FPS.
This mechanic will have to arrive in the next update or two with some of the new things coming, however 4J may implement a different method of handling such mechanics.
A sign takes up a block. (Though there's a transparent part and the sign is 'thin', it still takes up a whole block).
A chest takes up a block.
Two blocks can't occupy the same space.
You can put a sign in front of chest, and I believe you can put one on the wall above and behind a chest (and it still opens), but you can't put a sign ON a chest.
EDIT: Think ladder. It looks like a ladder is placed 'on' a block, but it still takes up a whole block. That's why lava blades work like they do.
But you can:
Place Item frame on a block (where the chest block you wanT)
then you break block only
then put chest
I just tried it myself to double check and I couldn't. What I didn't try was putting a block (i.e., dirt) on top of the chest. Now that may work (I guess turning a chest into a 'normal' block).
But I gotta ask:
1- What good is a chest that won't open??????
2- Why does that sign have to be actually on a chest?
A double chest would but I have mine (and I can't put a pic up right now) arranged length-wise recessed in the wall so even with a double chest I can only open on one side. So putting an item frame on that makes it so hard to open the chest...
Very clever, but its still only a 'half-fix' so to speak, hopefully the sneak/use mechanic makes its way in the next feature update.I personally don't like to use item frames as they count as entites and use if its anything like the PC counterpart is rather hard on rendering and can seriously drop the FPS.