Rigger
Member
I always seem to lose the small tube of hardener whilst still having half a pot of epoxy ,gel-coat,etc. How compatible are these hardners,will one type do most jobs??
epoxy hardeners
- Thread starter Rigger
- Start date
oldsaltoz
New member
G'day Jim,
The short answer is no, all hardeners are not the same.
It all depends on what the 'manufacturer has added' there are only about 4 companies in the whole world that manufacture epoxy resin, but over 40 brands at my last count, each adds their own secret ingredients to improve on the raw product.
Best advice is to do a little experimenting by mixing a few very small batches and brush it onto some cardboard, let it cure and test each one. The "normal" ratio is 5 to 1 resin & hardener, but you may find some at 4 to 1 and I know of at least one that is 3 to 1.
Check your samples to see how hard they are by pressing you thumb onto the sample when sitting over a 4 inch gap, then how far you can bend the board before cracks appear, then how far to break it, record each result alongside the mix used.
I would not recommend you use this brew in a critical area, but should be fine for filling and gluing minor items, but nothing below the waterline.
I Hope this helps, no response from others to date?
Avagoodweekend.........
The short answer is no, all hardeners are not the same.
It all depends on what the 'manufacturer has added' there are only about 4 companies in the whole world that manufacture epoxy resin, but over 40 brands at my last count, each adds their own secret ingredients to improve on the raw product.
Best advice is to do a little experimenting by mixing a few very small batches and brush it onto some cardboard, let it cure and test each one. The "normal" ratio is 5 to 1 resin & hardener, but you may find some at 4 to 1 and I know of at least one that is 3 to 1.
Check your samples to see how hard they are by pressing you thumb onto the sample when sitting over a 4 inch gap, then how far you can bend the board before cracks appear, then how far to break it, record each result alongside the mix used.
I would not recommend you use this brew in a critical area, but should be fine for filling and gluing minor items, but nothing below the waterline.
I Hope this helps, no response from others to date?
Avagoodweekend.........
William_H
Well-known member
And of course many epoxies are 2 to 1 while araldite is 1to1 so take your pick. Epoxy hardeners are not like hardeners for polyester. The epoxy hardener contributes to and becomes part of the final material in a chemical combination such that too much hardener leaves that material not combined while too little hardener leaves some of the first part not combined and any non combined material is a weakness. Like having a dance too many females or too many males is no good, you need just the right amount. Likewise if you tried to use male gorillas at your dance as a substitute you may get complaints from the ladies (or unmanageable delight) give it a try but not in a critical place. olewill
DrBob
New member
William-H is right. Epoxy hardeners are amine based chemicals whereas gel coat catalysts are peroxides. You cant use them interchangeably. I used to work in the sealants industry and whilst you might find epoxy hardeners from different manufactures seem to work, they may not achieve the ultimate performance. If you are using epoxies for a structural use, I wouldn' t risk anything other than what you get in a pack. If you are just filling a hole with the epoxy as a filler then you may get away with it.
Best of luck
Dr Bob
Best of luck
Dr Bob
