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DCO Question

shayla

WOW Framer
For big direct contact overlays, have you ever had the acrylic bow out in the front? This is about 45 x 62, with Optium, over the print, over two layers of thick batting, over Di-Bond, over artcare foam core. I could remove the points and do it again with less pressure. It can be squished down so there's about 1/2" of space between f.c. and the back of the frame in back, but I gave it room to breathe, so there's only 1/4" of space. Even so, the acrylic wants to bow in front. I've sent Jim a note, but am also asking here. Have you ever done a big acrylic/batting overlay and had it bow out in front some from the pressure? Is a bit of bowing ever acceptable?
 
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wpfay

Angry Badger
Weeeelllllll. When I go that big with acrylic, I prefer to use 3/16", maybe even 1/4", depending on the application. 1/8" does what you are experiencing, though you are thinking correctly that less pressure is better to minimize the bowing.
If there is sufficient surface friction between the back of the art and the mount, light pressure will hold the art in place. I'm thinking paper with a little "tooth" to it and a muslin covered backer.
The other thing is the amount of batting used. Thicker will transfer the pinching effect of fitting farther into the field of the acrylic (I'm sure Dirk has better terms for that), whereas thinner will keep the pressure closer to the perimeter. Does that make any sense? The thicker padding might be the cause of the greater bowing.

I'm out of theories for the day. Good luck!
 

framah

PFG, Picture Framing God
The rabbet, being only about 3/16" max needs to be cut deeper so there is more like 1/2" holding the acrylic in the frame.
...buuuuut... prefer to use thicker acrylic than only 1/8" for something that big.

Does Optium even come any thicker?
 

shayla

WOW Framer
The rabbet, being only about 3/16" max needs to be cut deeper so there is more like 1/2" holding the acrylic in the frame.
...buuuuut... prefer to use thicker acrylic than only 1/8" for something that big.

Does Optium even come any thicker?
This frame has a 3/8" rabbet. Yes, Museum acrylic comes thicker, but as Pat posted, it costs a lot more. (my paraphrase). I gave her that option, but she didn't want to pony up for it. I'll back it out some and then tell her this is what it's like with what she chose. Otherwise, I like having the batting behind it. It came with some waving, and this fills them in.
 

Pat Murphey

SPFG, Supreme Picture Framing God
Hinge it from the top and no batting - no pressure on the acrylic. It doesn't need it if it's hanging from hinges.

Oh, and reverse the sheet of acrylic that was bowed out. Plus the usual cautions of transporting vertically or on its back.
 

Jim Miller

SPFG, Supreme Picture Framing God
Maybe just use one layer of batting?
:cool: Rick
That might be a good idea if there are several layers of batting. However, since the batting, compressed during fitting, is the source of pressure between the acrylic and the art, removing too much could weaken the mount. In that case, the art could slip.

For an item of these dimensions, I'm guessing one or two layers of batting would not be sufficient.
 

Jim Miller

SPFG, Supreme Picture Framing God
Hinge it from the top and no batting - no pressure on the acrylic. It doesn't need it if it's hanging from hinges.
That could work, but it would not be a Direct Contact Overlay, and the acrylic should be fully separated from the art by a spacer - and for this large item, it should be a generous spacer.

Maybe there's a reason Shayla chose DCO framing for this piece. Hinging has limitations, too. For instance, if the art is wavy/wrinkled/creased, or tends to be attracted to the acrylic by static, or if handling & transit could tear the hinges, then the DCO might be the better choice.
 

wpfay

Angry Badger
Acrylic shape in a frame is effected by more than physical pressure. It also reacts to changes to humidity. If the humidity in the room is greater than the humidity in the frame interior, the acrylic will bow outward as the outer side absorbs humidity from the atmosphere. Reverse is true when room is drier than inside of frame. This effect usually will eventually stabilize in a room with a good climate control system.
Reversing the acrylic as Pat suggested might be a good idea, but the acrylic will eventually respond to the forces of pressure and environment.
 

Pat Murphey

SPFG, Supreme Picture Framing God
I'm not sure that I agree that contact mount with acrylic without batting is inappropriate.
 

shayla

WOW Framer
I appreciate this conversation, and hopefully, it also helps future archive searchers. In this case, the print has warping, so after consulting, it was decided that the pressure from the batting could help even that out. I'm wishing she'd gone for the thickest Museum acrylic, as that might have keptit from bowing a bit. But, she didn't. I kept the batting, backing out the framing points another 1/4" (except in the corners, where doing so made a gap between acrylic and frame; there, I kept the points farther in). Shooting points in with batting on a big one is an interesting experience. The height of point entry on the frame side is tricky to control.
 

Rick Granick

SPFG, Supreme Picture Framing God
Shooting points in with batting on a big one is an interesting experience. The height of point entry on the frame side is tricky to control.
I wonder if points are strong enough for an application like this. I would be tempted to at least squeeze in brads with a fitting tool, or even to use inverted offset clips screwed in to hold the contents in place.
:cool: Rick
 

MnSue

SGF, Supreme Grumble Framer
Shayla...could you add extra support with an inner frame and stack the acrylic between the two frames?
 

Jim Miller

SPFG, Supreme Picture Framing God
I wonder if points are strong enough for an application like this. I would be tempted to at least squeeze in brads with a fitting tool, or even to use inverted offset clips screwed in to hold the contents in place.
:cool: Rick
That's a good point, Rick...pun intended!:D
Offsets or sturdy turnbuttons, such as Infinity hangers, would be better than fitting points.
 

shayla

WOW Framer
I wonder if points are strong enough for an application like this. I would be tempted to at least squeeze in brads with a fitting tool, or even to use inverted offset clips screwed in to hold the contents in place.
:cool: Rick
Offset clips is a great idea! Wish I'd thought of it. Probably wouldn't work with the Z-Bar at the top, but at least on the sides and back. I didn't think of it, so just put in a million points. She has a smaller project in the shop, so I can offer to refit it.
After all, I've only done it three times already. (Once for this, and twice for floofy flums). Maybe it'll just become my new vice. 'Want to go to the movies on Friday?' 'No, I'd rather refit that big green devil.'
 
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