Deterioriating Foam in Instrument Cases?

This is a by-product of the "disposable" mentality. Polyester foam breaks down at about 15 years under normal conditions. Refrigerated storage might help. Poor design.

Ozone and heat accelerate the process. Some instruments by their very design generate ozone and heat internally. Keeping the foam away from direct sunlight certainly doesn't hurt, my experience is that sunlight accelerates the process even more.

Best long-term strategy may be to remove the foam while it's intact, before it deteriorates, and replace it. Especially if there's a fan to distribute the little gunky particles around, cleaning up after the fact is a real pain. This isn't always easy because often the foam is glued in place (and the glue tends to go gooey and gunky itself.)

Tim.

I would say most intenders intend it to last. but have been bitten including speaker companies. Better, as in lasting longer? I have not really seen any other common soft pliable foam.

greg

I doubt there is anything you can do about it. I'm sure that it is just something that occurs with a particular kind of foam. I've seen it in turntable mats and in instrument cases which hadn't been opened in 20 years.

My only solution is to try to make a nice replacement from something which I HOPE will last longer. So far, so good.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Cool, What did you use that you hope will last longer? mike

Depending on the adhesive used either automotive hand cleaner, or "Goo Gone" cleans up the mess. I scrapped a number of old Burroughs computer systems in the past to use for storage. they were full of the sticky residue.. I carefully lifted a corner and peeled away all that i could which left the sticky film from the double sided mounting tape. I laid the panels on a pair of saw horses out in the hot Florida sun and rubbed a couple fingers full of cheap hand cleaner and let it sit for an hour. I hosed it off, then removed the remaining bits of the double sided tape and used a little more hand cleaner to finish it up. The "Goo Gone" works on smaller areas, but it evaporates quickly so you may have to use a lot of it.

I have just used stuff that I found with packing material, and that SEEMED okay. This is totally unscientific. I've done this a couple of times and so far, so good, but one of them may break down next year and I won't have any better idea of what to do.

Sorry, but I really don't know what the stuff I used was. Not that it would have mattered much, because I don't know what the bad stuff was.

I've got some samples from a foam company. I should call them and see if they can offer any advise. I've used polyurethane foam in other applications and that seems to be very stable and durable, but they only had it in cream color. For the instruments I was repacking, I wanted black.

The polyurethane foam went into a VW engine environment. It has held up well with heat, oil, and fumes for about 15 years with no sign of breaking down, so I would guess that if you could find polyurethane that you liked, it would be a good bet.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Mike-

This is a common problem with light traps in 35mm camera backs. In one I had repaired, the foam was replaced by some kind of fiber/felt material. It hasn't been many years, so it is hard to tell how long it will last. The adhesive will probably fail before the material.

For instrument cases, some kind of cloth covering the padding material might be helpful. One candidate for padding would be from a pillow. I had a foam pillow that lasted for many years without turning to gunk.

Fred

Depends on the type of foam. Black or dark grey foam has more oils in it hence the reason why it turns into a greasy, gunky mess when it passes it's cure date.( oils are an essential part of the pigment.) This is also the reason why white foams don't turn to gunk. They'll just turn yellow/brown and eventually flake to dust. You could esaily replace the old black foam with white foam and it'll work just as well. Just be sure to get the same density for shock protection value. You could also cover the white with fabric, either felt or crush vallour/velvet. Cut your white foam to fit the case as well as the instrument that'll be stored in the case.(I use a long smooth edge bread knife sharpened to razor sharpness. Utility knives and exacto's will work as well. Just bear in mind that foam is a synthetic that really dulls any edge quickly. have plenty of spare replacement blades on hand.) Applying a cloth cover is easy. Just spray the foam surfaces with a spray adhesive like Super 77(3M) and press the fabric as smoothly as possible into the cutout for the instrument, the going in a circular pattern outward press the remaining cloth onto the outer "top" portion of the foam. Trim the edges leaving about an inch or two to spare to allow for "tuck in" between the foam's edge and the case walls.

Another good foam to use is the type used in marine applications for boat seating and padding. It's a hard, closed cell white foam with a smooth finish. Good for high shock applications. Can be gotten at most boat or marine supply shops. Also has the advantage of having a very long cure date.(will last for many years.) When used in conjunction with less denser foam in a multi-layer configuration provides the greatest shock protection.( an inch or two of marine foam on the case walls and two or so of soft foam on top)

Black foam is used primarily for it's cosmetic value. After all to most guys black foam just looks cooler in a shock case.