For a one off how about just roughly carving something out of bulk polystyrene packaging and loose fill the interior with the bits that break off or come with your next consignment of fragile parts?
Rigid polyurethane foam will tend to stress the components. I have seen damaged car panels by putting too much PU foam into a confined space! It is still the method of choice for fridge freezers.
The semi rigid packaging grade isn't too bad for stressing things if you can get a hold of it but wrap the part in cling film or similar first. I have a feeling it isn't a particularly good closed cell foam.
Urea formaldehyde foam for cavity wall insulation would be another option if you can find someone who will make you a bit.
Flexible PU foams use more noxious reagents (serious lung sensitisers).
That's good.. PS is not only low temperature stuff, but it's not exactly petroleum solvent resistant. I clearly remember the one time I poured a bit of gasoline into a styrofoam cup. When the revolution comes, it will be useful for DIY napalm.
There's also Polyimide insulation if you're feeling rich, or even aerogel (which outperforms all the others by a large factor).
The chemicals may not be friendly, and it may gas them off for a while.
Now you tell me. A week ago I went into the attic to add a backing plate to an anchor that had pulled out of the ceiling on a fluorescent in the laundry. Had to fish around in 8" batts to find it :-( After much hand lotion and a prescription from the Doc, the itching has finally subsided. ...Jim Thompson
| James E.Thompson | mens |
| Analog Innovations | et |
I think rock wool has coarser fibers or something.. anyway it's not as itchy. I did some controls for the Roxul plant which makes the stuff (just down the road), years ago. It costs a bit more than fiberglass.
We have something that will save all that labor- raccoons. The b*ggers will rip all your insulation to shreds if they can find a way in. Smart too, and quite dexterous.
I've seen the low frequency phase noise of a cheap XO go down by 5:1 when a small cover was added to block air currents. We used a plastic potting shell. Opamp circuits can behave similarly.
Try some cotton balls; my wife keeps them around for some mysterious female cosmetic use.
My experience, measuring the power drawn by a small OCXO under a cover, is that, in a small volume, insulation makes things no better, and usually worse. There must be some size scales where convection matters.
Here's a temperature-controlled analog thing:
and an OCXO with its cover, lower right
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Well I don't think they are all the same. I'm not sure what rock wool is, then there's the fibre glass that's used for insulation. (As someone said that makes my skin itch.) But we also used a glass wool in the lab. It was white... and never made me itch. I went looking for it in McMaster-C, but didn't find it. Listed in Cole-Parmer... kinda spendy. (~$100/lb.)