Repair & maintenance: 'Old' Epoxy Resin

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'Old' Epoxy Resin - useable ?

Printed From: Yachts and Yachting Online
Category: General
Forum Name: Repair & maintenance
Forum Discription: Questions & tips on the subject
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=4576
Printed Date: 14 May 25 at 12:54pm
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Topic: 'Old' Epoxy Resin - useable ?

Posted By: Fin.
Subject: 'Old' Epoxy Resin - useable ?
Date Posted: 27 Aug 08 at 9:09am

I've a few repairs lined up.

looked at my pots of epoxy resin and noticed the dates are passed.

Will it still be possible to use it - how critical are the (best before) dates ? (4-5 months out of date).

Will the hardner and resin react and bind correctly?

Chemists and boat builders (anyone else for that matter) - opinions welcome :-)

Thanks

fin

Replies:

Posted By: JimC
Date Posted: 27 Aug 08 at 9:36am

Originally posted by Fin.

Will it still be possible to use it - how critical are the (best before) dates ?

You've got to ask yourself one question: 'Do I feel lucky?' Well, do ya punk

If I was doing some filling and fairing or something where strength wasn't crucial I'd use it. I might let a little test piece cure off first just to check. Depends on how well I'd stored it too... If it was something structural or would be a hassle to pull apart and redo afterwards if it hadn't cured well I would't.

Posted By: alstorer
Date Posted: 27 Aug 08 at 1:04pm

The Epoxy component will probably be OK. There's little in it that will react much with air, or "go off".

The Hardener is another matter. The amines undergo carbonation in air- this will form a yellowy skin on the surface of the component. Problem is, if it's something like West 205/206 this is a yellow liquid anyway- the more engineered (aerospace) systems we develop here have large amounts of filler and colouring, and the degredation causes very obvious changes to the colour

If it's just four to five months out of date, then I'd suggest scraping this layer off and using it as normal. If it was a year out of date, then Jim's advice kicks in. If it's much than that, I'd dispose of it. However, i'm not quite sure what the best route for disposal is. They really shouldn't go to landfill- our amine and epoxy waste goes for incineration.

Posted By: Fin.
Date Posted: 28 Aug 08 at 10:31am

thanks folks

- will check the hardner. I have some foils (trailing edges) to repair.

I think I'll use remainder to fix an old kitchen chair ;-) , and misc items.