"Shelf life of polyester putty" Topic

I bought a putty-and-hardener set of Tamiya green polyester putty about 12 years ago for applying zimmerit to 1:35 vehicles. Would an opened tube still be any good? Also, I tried to open it and found that the twist cap is very firmly in place and if I try to force it open, it will tear the aluminum tube. Is there a better way to get it open?

Can't talk about Tamia putty. I do know that opened milliput and greenstuff (Kneadite) – mostly what I have experience of – tends to degrade after a while.

Whatever it is that keeps the putty 'malleable' seems to evaporate or – in some other way – leech out and the stuff becomes unworkable (or, at least, unsatisfactory with lumps and whatnot in the putty).

And if you have to cut the tube open or uncrimp the far end, it's gonna be a one time use anyway.

I'd try and use if for something less vital and all in one (like some figure basing, perhaps) and then bite the bullet and buy some new stuff.

John T

EDIT: PS – when you buy some new stuff, unless you are using it every day, keep it in the fridge. All the stuff I have lasts longer in cool temperatures

Snip the end off the tube. It is likely only the top portion, exposed to the air has hardened. You may need to cut you way partially down the tube to get to any salvageable portion.

You will need to find a way to close it back up tightly after you do that. Recommend finding a small air tight container, like Tupperware, and putting any workable material in that.

Second the idea of keeping it in the fridge. All polymers will break down eventually; cold retards this process.

Is the rest of the tube still flexible? A common disaster is putting the wrong cap on the tube which results in one tube going hard and the other tube having the cap welded on. DAMHIK.