Polystyrene Cement

[Aaron D. Parks]

Hopefully this is the right forum for this.  If not, please let me know!

I've got a project that involves some hand-wound toroids.  After getting them tweaked and tuned, I wanted something to hold the turns in place (didn't want to have to hold my tongue at the right angle the whole time I was using it).

I'm familiar with Q-Dope from MG Chemicals, but I didn't have any.  What I do have (and perhaps you do too) is an overabundance of polystyrene packing material.  So, I reached for some solvent and made up a nice polystyrene cement.

It's simple enough, but I thought it was a trick worth sharing so I put together a short video.  Kinda fun to watch the bulky foam disappear into such a small volume of solvent.

Have you got any other fun tales that involve beakers on the bench?

[bookaboo]

Interesting, thanks for sharing. Do you get any fumes or nasty smells when dissolving?

[SeanB]

Making heat sink compound using zinc oxide powder and silicone grease, with the solvent being trichlorethane. Worked well but the fumes meant mixing was done best by the open window with the bench fan blowing the fumes outside. When mixed well leave overnight outside till the solvent has flashed off, then use as needed.

Came in handy doing shed loads of TO3 packages.

[Aaron D. Parks]

Interesting, thanks for sharing. Do you get any fumes or nasty smells when dissolving?

Just the characteristic solvent odor.  Nothing extra from dissolving the foam.

Making heat sink compound using zinc oxide powder and silicone grease, with the solvent being trichlorethane. Worked well but the fumes meant mixing was done best by the open window with the bench fan blowing the fumes outside. When mixed well leave overnight outside till the solvent has flashed off, then use as needed.

Came in handy doing shed loads of TO3 packages.

TCE?  Oh my!  Cool story, thanks! 

[HighVoltage]

Nice video, thanks.
And a great idea.

I have not seen this M.E.K. Substitute canister, since I lived in the US.
May be it is available is Germany, probably some kind of "Butanon", I will have a look around for that.

[MK]

You can get MEK from ebay, I thought packing material would  be too variable for quality and general embedded dirt, so when I made some I used broken CD case material, take any of the multitude of broken/damaged clear cd cases from around the house, break some up into smaller pieces and soak in MEK, wait a few days for it to even out, add solvent or case peices to get the consistency as required.

[Aaron D. Parks]

You can get MEK from ebay, I thought packing material would  be too variable for quality and general embedded dirt, so when I made some I used broken CD case material, take any of the multitude of broken/damaged clear cd cases from around the house, break some up into smaller pieces and soak in MEK, wait a few days for it to even out, add solvent or case peices to get the consistency as required.

I didn't realize CD cases were polystyrene.  That's really handy to know!  I think just about everyone has a few busted ones around.  Thanks!

[rdl]

I haven't bought any lately, but plastic model cement from the hobby store used to be primarily MEK. Not the thick stuff but the very thin watery kind you apply with a brush. I think the thicker glue that comes in a tube has polystyrene already dissolved in it, so maybe a blend of the two would work? I don't know for sure. I'm sure MSDS are available though, so it shouldn't be too hard to check.

[MK]

I just noticed that you used the pink poly chips, they are meant to be anti-static and have something conductive added to reduce esd damage, that might lower the Q of your coils?

[Aaron D. Parks]

I just noticed that you used the pink poly chips, they are meant to be anti-static and have something conductive added to reduce esd damage, that might lower the Q of your coils?

Could be.  I think that most anti-static agents work with moisture in the air to dissipate charge on the surface of the material, rather than by increasing the bulk conductivity. 

In any event, you raise a good point: it's hard to say what all might be in there when you're dealing with recycled materials.  In this case, the pink dye gives us a clue, but we still don't know all the details.

Edited to add: Incidentally, this might touch on a reason not to be too aggressive in cleaning ESD mats.  In the upper layer, only the anti-static agent near the surface functions to dissipate static.  If you remove it with aggressive cleaning, bad news.  I wonder if those specialty ESD mat cleaners include additional anti-static agent?

[Richard Crowley]

You could probably do the same thing with acetone.  We used acetone and MEK interchangably as solvent/cleaner in a variety of polyester plastics fabrication use cases.

[Aaron D. Parks]

You could probably do the same thing with acetone.  We used acetone and MEK interchangably as solvent/cleaner in a variety of polyester plastics fabrication use cases.

I would expect so.  On the other hand, I had someone tell me that it didn't work well for them (came out stringy).   

I chose ethyl acetate for longer drying time.

[SeanB]

If you want to clean the anti static mat use regular fabric softener, 1 teaspoon in a half cup of warm water, then wipe the surface down with it, then wipe again with a damp cloth. That will not harm the film, and the thin coat left on the surface will dissipate static. Plus it leaves a nice smell in the room.

[timb]

If you want to clean the anti static mat use regular fabric softener, 1 teaspoon in a half cup of warm water, then wipe the surface down with it, then wipe again with a damp cloth. That will not harm the film, and the thin coat left on the surface will dissipate static. Plus it leaves a nice smell in the room.

You can also dampen a dryer sheet with warm water and use that by itself to clean the mat if you don't have any fabric softener. (It acts as your towel & cleaning agent all in one!) Has the same effect of reducing static and making it smell nice, too.


Sent from my Smartphone

[Aaron D. Parks]

If you want to clean the anti static mat use regular fabric softener, 1 teaspoon in a half cup of warm water, then wipe the surface down with it, then wipe again with a damp cloth. That will not harm the film, and the thin coat left on the surface will dissipate static. Plus it leaves a nice smell in the room.

You can also dampen a dryer sheet with warm water and use that by itself to clean the mat if you don't have any fabric softener. (It acts as your towel & cleaning agent all in one!) Has the same effect of reducing static and making it smell nice, too.

Brilliant!  Thank you!   

Oh, man... that room could use a nice smell, too.