Preserving those thermoformed inserts

[HobbyistWolf]

We're all familiar with the thermoformed plastic inserts that come in the sturdy metal cases of the 40-piece metric/imperial socket sets from the 60's-90's, right? They do their job well when new but over time they sag, crack, and generally fall apart as they age. Now, filling in the underside with something to support those heavy sockets can keep them looking and working like they were intended. One method I've seen is using expanding foam and cutting off the excess after it sets up. But, since it expands in all directions, it can cave in the thinner/weaker areas if you're not careful. So I'd like to hear what other things people have used! Something liquid that turns to a solid when it cures would be ideal to get into the small nooks for better support. Once I have the one in the best condition stabilized I may try duplicating it via a mold to replace the irreparable one. (I have three such sets, each a different case color and make! XD) Thank you for reading and any suggestions!

 

[slow]

I've never tried it, but could you fill the backside with urethane or an epoxy?

 

[ynned]

I've no idea of the expense, but the movie industry uses some kind of pourable(?) latex that ought to do nicely.

 

[Milton Shaw]

Easiest and by far the cheapest would be Plaster of Paris. Cheap and sets up in less than 30 minutes, no smell and plenty strong. You might put some mesh in the top of the mold when you pour to be in the bottom when you turn it over to give it more strength sort of like rebar..

 

[gungatim]

maybe try a quart of that liquid stuff they sell on tv, flex seal I think it is called...

 

[Stuart in MN]

You can get low expansion foam in a can, it would be a better choice than the regular stuff.

 

[HobbyistWolf]

I was thinking of using a urethane or epoxy, just have to be sure it's rigid when cured.

Latex might be too flexible for the warped one I'm repairing, but might be okay for one of the better ones, though I'm not sure how it wears/degrades over time and with possible exposure to oil/grease.

Plaster is strong, but isn't it brittle? Also not sure how it would hold up to oil exposure (could be sealed I suppose), whether shrinkage would be an issue and whether it would be thin/runny enough to get into all the small spaces. I suppose it can be watered down for that, but that might affect its strength/shrinkage rate.

Flex-seal would work on sealing the cracks in it, but I think it wouldn't be stiff enough for adding support.

Ah, I'd forgotten low-expansion foam was a thing! That would work decently, though it would still be tricky to get in the small gaps and I don't know how it reacts to oil.

Great suggestions, now I need to visit the local hardware store to assess prices, thank you all!

 

[gahrajmahal]

How about bondo, or lay up some fiberglass behind it.

 

[HobbyistWolf]

Hmm, I do have an old unopened tub of bondo. Heck, I might try laying cling-wrap over bondo and bedding the sockets in it to create a holder from scratch! Fiberglass backing an excess of resin might work.