Boat Building Forum

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Post cure
By:Pete Rudie
Date: 4/6/1999, 12:37 pm
In Response To: Re: Paint (Stan Heeres)

Quite right, George has said that he does that. At ambient temperatures epoxy will build to +/- 70% of final strength in the first 24 hours, and continues to cure at a decelerating rate for several weeks. In the 40-50 F. range this could mean that sanding has to wait for 2-3 days. By wrapping the boat in a heat-absorbing material the cure cycle is accelerated.

Too much of a good thing is a bad thing, though. Heat is the mortal enemy of epoxy. It softens at 160 or so (depending on the type). If left to its own devices it will stay where it's put and regain all of its former strength after being allowed to cool. However it is fragile while hot, thus subject to dings and scratches. Furthermore, heat lamps of the type normally used to bake automotive finishes are far too hot for epoxy. They will accelerate the cure for a short time, and then cause blistering, delamination and possibly fire. George's method is a good way to gently nudge the curing process, but beware of the dangers of more energetic intervention with the chemistry.

> I've seen where someone (I believe it's George) lets epoxy do a normal
> cure and then wraps it in black plastic and lets it 'final cure' by
> putting it in the sun. This type of treatment should give you the 'bake'
> you are looking for.

Messages In This Thread

Paint
Mike -- 4/6/1999, 2:16 am
Re: Paint
Brian -- 4/7/1999, 12:46 am
Re: Paint
Nolan Penney -- 4/6/1999, 8:16 am
Re: Paint
Stan Heeres -- 4/6/1999, 12:16 pm
Post cure
Pete Rudie -- 4/6/1999, 12:37 pm
Re: Paint
Paul Lund -- 4/6/1999, 7:11 am