Smoking fiberglass

[lapworth]

Last night was a little warm but I need to do some fiberglass work. Well I mixed a small batch and used most of but the stuff I left in the pot started to smoke while working. Could I have used the smoking glass ?

[brak]

just to be a stickler, you probably mean epoxy. epoxy cures with production of heat and, especially if it is hot outside, it may begin giving off smoke or even catch fire (happened to me once). generally, once it starts getting overheated, that means it is being cooked and the resulting material will be theoretically more brittle and less strong than properly cured.

you could have quickly cooled it (dispersing it in a thin layer over a large surface like a single-use tray may help), also using slower hardener will increase its pot life in hotter temperatures.

[sailingdog]

Actually, all of the reactions for curing resin—epoxy, Polyester and Vinylester—are exothermic and can generate significant heat. Any of the commonly used resins would smoke, especially in hotter temperatures and if they are in a tall narrow container, rather than a wide-flat container.

No, using it would have been a mistake.

Things you can do to help the resin take longer to cure:

1) refrigerate or cool the components prior to using them... the components will have to heat back up to become really active.
2) use a wide flat container so that the heat from curing is readily dispersed
3) use less catalyst for polyester/vinylester resins and a slow hardener for epoxy resins.

[lapworth]

Thanks for the advise guys but my wife already hates when I work with this stuff so the hole frig idea would be a Big No!

[paulk]

Instead of the fridge, you can also put the bottles in an ice bath- like a wine cooler bucket.

[tommays]

I had the same thing last night BUT new it was going to happen so i spread it out over the core really FAST to avoide the heat issue

If you are going to keep working in the current heat i would go with a slow hardner as my brand comes in 3 speeds for weather changes

[sailingdog]

You can also put the container you're mixing the epoxy in into a water bath or ice bath.

[mitiempo]

Years ago I switched to using only slow hardener unless working in cold conditions (I use West) and it gives you the extra working time you often would like. Still cures in a reasonable time for sanding, etc. I use the West pumps so mixing is fast and easy. I mix in smaller amounts and if I need more it only takes a few minutes to mix another small batch as there is no measuring.

[QuickMick]

I use the 'small batch' approach too, it also helps insure you get to use all your material before it starts to set