[Tfug] And another one down

[Timothy D. Lenz]

That foam you buy in cans  will keep expanding some for days, even weeks 
depending on conditions, though at a much slower rate. I read about 
someone that put it on the inside of his computer case pannels, but 
latter when he went to work on it found it very hard to get the pannels 
off because it had expanded more after he put it back together.

On 9/16/2013 8:17 PM, Bexley Hall wrote:
> Hi Zack,
>
> On 9/16/2013 8:20 AM, Zack Williams wrote:
>> On Sun, Sep 15, 2013 at 11:54 AM, Bexley Hall <bexley401 at yahoo.com>
>> wrote:
>>>>> If you really want to ship robustly, you put 2 inches of "foam"
>>>>> around the item on all sides as the outermost "shell".
>>>>
>>>>
>>>> As a matter of fact, if you dig in the UPS tariff, it mentions the two
>>>> inch cushioning figure, I believe. You go to their Silverlake location
>>>> or a UPS store, they sell expandable polyurethane foam bags. not
>>>> cheap.
>>>> Not as good but guess you could roll your own with spray foam and
>>>> garbage bags.
>>>
>>> I use the "Crazy Stuff" foam.  Probably something cheaper out there
>>> but this is really convenient.  It doesn't appear to be exothermic.
>>> Or, at least not greatly so.
>>
>> Just make sure the plastic is thick enough.  I received a fairly heavy
>> UPS battery module that was packed in this way once, but the plastic
>> had ripped open in the packing process as the device had somewhat
>> sharp corners.  The foam glued the packaging to the unit as well going
>> inside the vents and gumming up some of the device connectors.    It
>
> Sounds like the plastic got *torn* when the device placed inside it
> (etc.)
>
>> was a total mess.    If you do this, I'd recommend pre-wrapping just
>> the device with plastic, then another layer of plastic to hold the
>> foam.
>
> When I first saw this done, I noticed that the packer had the device
> in the shipping box and laid an oversized sheet of (some sort of)
> plastic over it.  The plastic was larger than the box opening.
> It was then "tucked" down around the sides of the device.  Then,
> this was filled with foam, the excess plastic tucked over the
> top and the box closed *before* the foam had completely expanded.
>
> I think these "professional" packers either have aa different
> type of foam or are really skilled at metering it out.  I know
> that I can't close the box until I've watched to see how much
> the foam expands -- then, trimming it to the right size before
> closing.
>
>> I'm a fan of the "wrap the entire thing with bubble wrap a few times"
>> method, which tends to work well for most rectangular items.
>
> The problem with bubble wrap is dealing with large objects that
> have concavities.  The bubble wrap doesn't "cling" into those
> concavities so You end up with a big air pocket.  By contrast,
> the sheet of plastic with expandable foam will conform to
> damn near any shape.
>
> The ASR-33's challenge is the mechanism has a *lot* of weight.
> If that weight were to be applied to the plastic shell, it
> would undoubtedly crack (e.g., if box was ever turned on its side
> or upside down).
>
> So, I have to remove the mechanism and bolt it to a piece of
> plywood that fits tightly in the bottom of a box.  Then, put
> some wood or stiff foam blocks in the corners to ensure the
> plywood can't move away from the bottom of the box -- even if
> the box is inverted.  Finally, lay the cover in place and
> do the foam trick around that.
>
> Or, ship in two separate boxes -- the second of which has no
> weight but lots of volume!
>
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