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[scot]

Is there a recommended time for curing in the vac?
eg; pot life + 1hour

If I use the Kinetix epoxy from atl how long should I leave the vac system going?

the stats for kinetix are:
Pot Life -100g @ 25ºC (in air)       25 mins
Mix Viscosity mPas @ 25oC           500
HDT after 28 days @ 25ºC             46ºC
4 hours @ 60ºC                                75ºC

cheers,
scot

[dougirwin13]

Hi Scot,

This is probably best covered by Bert's original thread on Swaylocks.

The thread is called Vacumn forming & Sandwich construction and covers pretty much all of the basics of vacuum bagging composite construction surfcraft.

Initial cure in air might be 25 minutes, but that's only a partial cure.  I'm inclined to leave it in the bag for 8 to 12 hours myself.

Regards,
-doug

[paul cannon]

heya scott
i usually leave in about 12 to 36 hours
12 in summer
up to 36 in winter
it takes a few days if it real cold
or alternatively you can use a heater box

i just published a stack of bagging tips
in the articles board

[Kit Sidwell]

At the risk of giving too many different replies to one question -

Always test an epoxy to become familiar with how it behaves.
Mix a little batch, laminate a scrap of cloth to an offcut of balsa, and check on it every half hour by touching it with a gloved hand.
You'll notice it getting less and less tacky over time.
It is very temperature dependant, so remembering how warm it is is a very good reference point.
The board should stay in the bag for at least enough time that the resin won't be tacky.

Then you can peel the glass off the test piece, hit it with a hammer, all sorts of fun tests.
I can't imagine how many test panels I have done.
There is no substitute for a real life experiment

Kit

[scot]

Thanks guys for the replies.
I think my vac setup will need an upgrade to go for that long.
If I was to preglass one side of the skin before attaching to the foam would a hand lam be OK? How critical is the vacuum?
Is it the pressure that is key or the lack of air?
For my first go I am not too stressed about weight as i think it will be leighter than my old poly anyway. I am going down this path to get a stronger board that i wont kill after a few weeks.
thanks,
scot

[dougirwin13]

IMHO a simple vacuum switch is often a better answer than a new pump.

And you can still use it when you finally decide to get a new vac pump

-doug