River table, 1st layer catastrophe


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sebastien mangin
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Hi, 
I would like your advice on a trouble I had with my third river table.
I live in Reunion island (and speak French). 30 degrees Celsius all year.
I use GC10. My 2 first tables were fine, no trouble. 
This time, I poured the first layer, after mixing properly,  2.5 cm. I did notice that the resin was smoking and took fire easily when trying to remove the bubbles with torch (I must buy a heatgun).
The b stage came after around 6 hours by 30 degrees. 
I poured my second layer.  
3 days later, after removing my barriers the second layer is perfect, but the first one is a mess. Gummy, sticky, I can move it by hand. That texture reminds me those Salvador Dali's watches.
I used a small glass of the first layer for brushing the top of a former table and it was sticky for 3 days.
What did I miss ?
Thanks for your help.





Edited Last Year by sebastien mangin
Warren (Staff)
Warren (Staff)
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First of all, the reason it got very hot is because you are using the wrong resin for such deep casts AND working in hot conditions.  GlassCast 10 is designed for up to 10mm layers.  25mm is way too deep and on its own could cause problems with exothermic heat.  Plus being at 30C can cause it to cure off quickly.  

The correct resin is GlassCast 50 which at 20C can be used in wood up to 25mm per layer.  However at 30C we would recommend doing thinner coats as its right on its limit doing 25mm at 20C and higher temperatures can easily push it over the edge and cause excessive exothermic heat.

In terms of not curing properly that would be either a measuring or mixing issue.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
sebastien mangin
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Warren (Staff) - 5/6/2020 8:29:32 AM
First of all, the reason it got very hot is because you are using the wrong resin for such deep casts AND working in hot conditions.  GlassCast 10 is designed for up to 10mm layers.  25mm is way too deep and on its own could cause problems with exothermic heat.  Plus being at 30C can cause it to cure off quickly.  

The correct resin is GlassCast 50 which at 20C can be used in wood up to 25mm per layer.  However at 30C we would recommend doing thinner coats as its right on its limit doing 25mm at 20C and higher temperatures can easily push it over the edge and cause excessive exothermic heat.

In terms of not curing properly that would be either a measuring or mixing issue.

Thank you for your advice. I realise that I order the GC 10 instead of 50 by mistake. It explains why the hardener delivered is short for this work. 

I appreciate your helpful explanation about external temperature and layers. 

I use a digital scale for measuring and mix for 4 to 5 minutes cautiously. My second layer 2.5 cm as well was made exactly the same way and cured perfectly. 
Does a deficient pot of hardener can occur ?

I removed 1cm by hand and I am planing to rebuild barriers in order to pour a small layer. 

Thanks again


Warren (Staff)
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Its extremely unlikely especially if it came from the same batch.  You could always do a small test mix to be sure?

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
Edited Last Year by Warren (Staff)
sebastien mangin
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Warren (Staff) - 5/7/2020 10:21:26 AM
Its extremely unlikely especially if it came from the same batch.  You could always do a small test mix to be sure?

I did already in order to clear up a former table (only the resin part) with a translucid layer painted with a brush.
It got sticky and marked my fingerprints 3 days later. 
Anyway I used the all pot on my first layer. I started a new one for the second layer and no trouble. 
Thank you again and take care.

GO

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