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Does Heat/Freezing Affect Acrylic Boxes?

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Shayla

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Does exposure to temperature extremes cause acrylic boxes to shrink or expand? I suppose it depends on the tolerance range of whichever plastic is used, but what say?

And does someone out there make them cast, without seams? (SmallCorps, maybe?) If so, at least there wouldn't be any seams to pop. I was thinking about the need to order adhesives before freezing temps occur, and remembered the thread where the glued box seams have popped. Doubtful that they froze, but it got me to wondering how temperature resistant those plastics and glues are.
 

JFeig

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I doubt that anyone would want to pay for a monolithic cast acrylic box. In theory is can be done; however the cost of a mold for a "one-of" box would not be cost effective. Molds also have a rough time with 90° corners. As a rule of thumb the radius of a corner has to be 6 times the thickness of the material being formed.
As for glue vs temperature change, acrylic boxes are not constructed with glue. Solvents are use to melt the acrylic so that the joints are "fused together" to become a single item.
 

wpfay

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Taking Jerry's explanation a bit farther, the acrylic does react to changes in humidity and temperature, but because it is all the same material it should react uniformly. A scenario where there might be of concern is when a tight fitting wooden stretcher is inserted in the box in a warm, humid environment then the piece is shipped to a cold, dry environment, the acrylic would likely shrink, but the strainer, not so much. This could put enough stress on the acrylic for failure, but, if properly constructed, not necessarily at the joints.
In my experience, the weak spots in a well made acrylic box are the screw holes.

IMHO If you don't have SmallCorps Optium samples, they are well worth the small (pun intended) investment.
 

Shayla

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So, for those with seams that fall apart, (as mentioned in another thread), would temperature not be a factor in that? Not saying it caused the current problem, but I'm wondering if shipping one in winter, or extreme heat, could ever be problematic.
 

wpfay

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It would depend on the quality of the join. Theoretically the process fuses the two pieces together into one, and there should be no difference in strength from the body to the joint. If there are any flaws in the joint, bubbles in particular, then the joint won't be as strong as it could be.
On its own, with no restriction of movement, the completed box should expand and contract uniformly. Acrylic, unlike wood, has no "grain" so there should be no differential in reaction to environmental changes.
The force of impact, or a restriction to expansion/contraction might put greater stress on the joints, but it isn't necessarily the joint itself that will fail.
It all hinges on the quality of the preparation and assembly techniques.
As I mentioned, check out the samples made from Optium from SmallCorp.
What does Dirk have to say about this?
 
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Shayla

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It would depend on the quality of the join. Theoretically the process fuses the two pieces together into one, and there should be no difference in strength from the body to the joint. If there are any flaws in the joint, bubbles in particular, then the joint won't be as strong as it could be.
On its own, with no restriction of movement, the completed box should expand and contract uniformly. Acrylic, unlike wood, has no "grain" so there should be no differential in reaction to environmental changes.
The force of impact, or a restriction to expansion/contraction might put greater stress on the joints, but it isn't necessarily the joint itself that will fail.
It all hinges on the quality of the preparation and assembly techniques.
As I mentioned, check out the samples made from Optium from SmallCorp.
What does Dirk have to say about this?
He doesn't have much experience with acrylic, but since he knows so much in general, I'll ask.
 
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