Thread: Where to get foam?

Hi Michael,
have you tried Spotlight. I tend to find interesting 'workshop' stuff everytime I go in there.

Phil

Originally Posted by Michael G

Clark rubber .... foam is either too soft, too hard or too thick.

Michael,

As you have discovered, getting small quantities of foam to specification is a pain. Most instrument cases seem to be lined with open cell polyurethane foam in flat sheets (so the instrument is pressed into it when the lid closes). That type of foam is easy to find in various densities, but not necessarily in your choice of colour. If you can get the colour and hardness you want, the thickness issue is easily fixed. (If you are looking make a case liner with the instrument dropping into a routed depression, it's probably closed cell foam you want.)

Open cell foam cuts well on a woodworking bandsaw. Fit MDF faces to two angle plates, grab the foam between the two plates to hold the over-thick foam piece up on edge, then split it down to thickness, using a fence to control the cut nicely. Go slow - too fast and the foam will want to disappear down the slot.

No bandsaw? When 'Er inside is not watching, nick the electric carving knife and use that instead. Put the foam on the bench between two parallels (bits of wood) of the right thickness and slide the knife blade along the top. Watch your digits. Nothing like as nice as a bandsaw, and you will need to put the cut face to the bottom of the box.

Cheers,
Bill

Yes arts and crafts suppliers would be a place, along with packaging suppliers...

G'Day Michael,
I have relined a few instrument cases using cut up mouse mats (remember them), the ones I have used are 6mm thick high density foam with a black fabric bonded to the face.
Regards,
Martin

Michael I can't answer your question, but I can ask another one (I'm here to help).
Which type of foam should be avoided because it causes rust?

Originally Posted by Bryan

Which type of foam should be avoided because it causes rust?

None of them cause rusting I hope - never heard that one before. I would imagine if the foam was acidic it could, especially if there was some moisture there. This may have occurred when particular foamed materials were new to market but I would hope that producers have their processes better controlled.

On the original quest, I tried Spotlight and Lincraft and neither of them had thin foam material. Cushion pads were as thin as they got - Odd because I would have thought it would be used in costumes. On the way home I stopped in at a different and larger Clarke Rubber. and got a foamed EVA (?) material, closed cell in 3 and 6mm thicknesses (neutral gray sort of colour). It's still a bit firm so I may have to relieve some areas if it pushes the lid up too much but it will probably do the job.

Michael

I've read of people having instruments rust using certain foams, possibly on HSM or similar.
I lifted the acoustic foam on my headstock the other day to find the beginnings of a rust problem.
It's a grey, open cell material, but I have no idea what its initials might be.
Might pay to keep an eye on your protractor for a while.

Just a word of caution about foam, the optics for the HP laser interferometer came in Hewlett Packard wooden boxes with custom foam cutouts and over time the foam had degenerated into a stick tarry mess...

I don't know if it was just a problem with the particular foam they used, or if the foam had been exposed to some solvent, I can tell you it took a long time carefully cleaning..

Maybe modern foams are more stable?

Regards
Ray

Apparently there is a problem for many plastics to leach there plasticizer over time, not really a problem for their designed life cycle but more in the realm of artifact curation. note: PVC plastics become acidic as they break down.
-Josh

Just an idea. I have not tried it myself on a measuring instrument. But antistatic foam pads as used for electronic components are very easy to cut to any shape with a knife. The stuff comes mostly in deep black color (but also a pink is common), it is an open cell foam, comes in several thicknesses from 3 to 12mm and in all sizes including bulk rolls. I have found it not to decay spontaneously even after 20 years storage (but like most foams it does not like prolonged exposure to solvents in the atmosphere, like in a paint shop). And it does not appear to cause any sort of corrosion, after all it designed to store expensive electronic and micromechanic components. Just do a search for "anti static foam" in ebay.... Chris

Perhaps balsa would be able to be cut to your insert shape. A couple of rubber buffers could hold it in place.

Michael.

Take a look at this thread, and see if there's anything there.

Pamper those tools and instruments..

Not sure how you would go about that with an instrument case were you cant get in below.

Regards Phil.

I went in the Clark Rubber store near me to get some foam rubber to bolster a ute seat.

They had an "off cuts" bin, so I thought great will maybe get a cheap piece out of there.

After all, that's the normal setup with off cuts from my experience.

So I find a useful piece a bit larger than I really need, ask how much, and woman behind counter gets out the tape measure and calculator and proceeds to try and charge me full price.

Told her there was no way I would pay that and walked out never to return.

So Clark Rubber don't rate very highly IMHO.

Rob

I worry about foam degradation and outgassing of nasties that cause rusting or staining - I'd suggest going to a craft shop and picking up some felt and seeing what cotton based padding they have, or talking to a car upholstery shop for their recommendations!

(and nearnexus - I know what you mean about Clarke Rubber charging top dollar for offcuts - had the same treatment at the one here. )