Talk Composites - The Forum for Advanced Composites

Wood casting with GC50

http://www.talkcomposites.com/Topic31828.aspx

By Tobias87 - 1/27/2019 5:57:14 PM

Hello guys,
I am about to do my first project with epoxy and still have a few questions.
I have a piece of wood, that I want to put in a frame which I will then fill up with epoxy.
From this forum I gathered that it would be best to give the wood a thin coating with epoxy to prevent degassing into the main pour.
Usually you are supposed to let the coating cure fully and then give it a sanding before doing the main pour.
Now my piece includes a knothole and has a rough and uneven surface so sanding it seems out of the question.
Should I give it a thicker "thin" layer, until it is possible to sand or how else should I proceed?

Also in the tutorial video with Chris he says that it takes the GC50 about 12 hours to reach the "B stage".
Does that timeframe differ depending on the size of the object or project?
My frame will have a length of 10,5 cm, width of 9 cm and a height of 4 cm.

I would appreciate any advice you could give me,
Tobias
By SleepingAwake - 1/28/2019 9:45:55 PM

 
Tobias87 - 1/28/2019 5:50:46 PM
 
Rich (Staff) - 1/28/2019 5:17:43 PM
 
MarkMK - 1/28/2019 8:04:18 AM
For info, GC50 takes about 2 hours to reach a stage where it has hardened and it ready to laminate onto. This is assuming an ambient temperature of around 20 degrees. It's behaviour is very much akin to a normal gel coat in terms of curing and can be sped up a little by increasing the catalyst ratio, although 2% by weight is recommended. 

I


I'm fairly sure this post is about GlassCast50 rather than GC50 Mark so whilst your answer is true of the GC50 Gelcoat, its not applicable to the original post.


Absolutely right. Sorry if I did not make that clear. I will be using GlassCast 50.

So the time it takes the GC50 to reach the B stage is still 12 hours no matter the size of the project?

Thanks @Lester Populaire for your advice. I am just not sure, if that could work with my project since I have to do 2 pours.
Are there maybe any other workarounds to keep the wood from degassing?

I have no experience with the gc50, but at this small size you should be fine pouring only in one go?