Q: How To Keep Styrofoam From Crumbling

Beldar

Beldar

Full time employment: Posting here.
Joined
Oct 12, 2014
Messages
571
One project of late is restoring a Czech RF-10 manpack radio (Cold War vintage). It is packaged in a styrofoam container (box & lid) which slip into a vinyl carrying case. 1980 vintage.

The styrofoam edges are beginning to crumble slightly. This is not the high density foam used by crafters, rather it is the loose ball like construction. I've searched crafters forums & found potential solutions such as Gesso or FoamSeal spray, but don't want to destroy the foam with the wrong coating. I really only want to seal the edges.

The container is only used for storage but according to the maintenance documents it's been in service until 2006 so it has seen some use.

Any ideas? Any former packaging pros?

_B
 

Attachments

  • RF-10.jpg
    RF-10.jpg
    9 KB · Views: 190
Beldar said:
One project of late is restoring a Czech RF-10 manpack radio (Cold War vintage). It is packaged in a styrofoam container (box & lid) which slip into a vinyl carrying case. 1980 vintage.

The styrofoam edges are beginning to crumble slightly. This is not the high density foam used by crafters, rather it is the loose ball like construction. I've searched crafters forums & found potential solutions such as Gesso or FoamSeal spray, but don't want to destroy the foam with the wrong coating. I really only want to seal the edges.

The container is only used for storage but according to the maintenance documents it's been in service until 2006 so it has seen some use.

Any ideas? Any former packaging pros?_B
Click to expand...


I don't have any tested ideas. Can you get a similar piece of styrofoam to experiment on?
I have made Q-dope an electrical insulating liquid buy dissolving styrofoam in acetone and other solvents. but all you need is to melt the outside edge of adjacent balls of the polystyrene without dissolving the whole thing. It does dissolve quickly/easily.
You could try a varnish, or clear Krylon, I don't know if either of them have a solvent in them that dissolves polystyrene. But, probably, if not add a little acetone. My thinking is an airbrush paint sprayer, to have a very limited spray, yet enough to melt the polystyrene balls together.
Again you need practice pieces.
 
Styrofoam is very sensitive to solvents in most any spray paints (spray or most other canned paints). I have found that both latex paint (water based) and real Shellac provide a good sealant for that type of styrofoam. I can't say how well it will keep the foam from crumbling.
 
I recall, I had to paint the same type of Styrofoam with something, so I could fiberglass a section, or the fiberglass would dissolve the Styrofoam.

Putting a corner of fiberglass along the edges would change the look, but it would hold for decades.
 
Clear package tape would protect the edges or maybe laminating film shrunk to fit with a heat gun.
 
Pardon my omission above. Before using Shellac as mentioned earlier, I first covered the Styrofoam using the long forgotten, grade-school art class material, Paper Mache. (newspaper, flour, water and salt) Don't laugh. It really does work. Here is a pic of a couple of bucks for fiberglass work I made with this method and the parts made from them. Styrofoam covered with paper mache, smoothed out with drywall compound, then painted with Zinzer primer and followed with Shellac. The yellow tint is the Shellac.

For your purpose I would simply paper mache over the styrofoam and maybe shellac if desired. Instead of using newspaper I might try cutting up some tissue paper to reduce the buildup.
 

Attachments

  • doors.jpg
    doors.jpg
    102.3 KB · Views: 5
You can buy foam inserts that can be cut to shape. For bigger bucks, folks will cut them for you. Why not just replace with something more modern? Google custom cut storage foam.
 
Thanks for all the tips.

Cutting storage foam blocks sounds "easy", however I haven't found blocks of the right dimensions yet (the photo I posted isn't too clear as to the wall thickness). Plus, I would more than likely fark the whole thing up. :angel:

I have a scrap piece of similar styrofoam and will try some non-solvent based coatings to see if it affects the foam physically. And the shellac / tissue mache approach might certainly work. I only need to treat the edges, not the entire surface.

Thanks again.

_B
 
Are you trying to maintain the packaging in 'mint' condition - like archival or for the period? Or just protect the radio?

If just protection, I'd do the reinforced packing tape route, the stuff with the Fiberglas strands in it. EZ.

-ERD50
 
If you're for preservation, then just get a separate container to hold the styrofoam, and use a pelican (or cheaper knock off brand) case for the rest of the items.
 
I'd like to keep the original packing since it was functional in a military environment (although I bet it would be pitched/destroyed in a matter of days in the field). Strictly for looks. And the radio is rugged enough for general ham radio use (I won't be doing tactical summersaults in the backyard, etc). :LOL:

The packing tape approach might work too, if it adheres to styrofoam.

Thanks.

_B
 
The comment about it being vulnerable to solvents has me laughing. When I was a kid, my cousin and I were working on his little go kart. He asked me to get some gasoline from the garage, and thew me a Styrofoam cup.

As I walked through the door from the garage, I watched my cup of gas dissolve in my hand. Poof! :facepalm:

Anyway, I noticed a lot of this old school Styrofoam packaging is now wrapped in plastic, probably to contain the balls (micro plastic?) The ideas above about painting it are good. Wrapped in plastic is good. So how about making "plastic mache"?
 
polyester resin melts it immediately, do not try to glass with traditional polyester.
Epoxy resin does not.
 
You must log in or register to reply here.

Latest posts

Back
Top Bottom