I'm pretty sure there are some true chemists following this board based on the responses to questions I've seen. I wonder if one of them would take the time to please give me a brief description of the chemical process/reaction that turns a liquid resin and hardener into a solid material, either the epoxy we use to "glue" things together, or that we use to coat our threadwork.

I don't think it's a stochiometric reaction, like adding two parts hydrogen to one part oxygen to form water, but the recommendations are still equal parts of resin and hardener. However, there appears to be some flex in these proportions that will still provide an acceptable outcome, either for holding or coating -- so what is the reaction?

The reason I'm asking is because of this apparent flexibility in acceptable proportions (in spite of what sometimes appears on this board), and my wondering about three related specifics:

1) What is the degree of "slop" in proportions that will still provide a proper outcome?

2) What are the consequences of using too much resin and not enough hardner?

3) The converse; consequences of using too much hardner and not enough resin?

Thanks.

Bilgee

I think the only thing you will find published from a credible sourse are the exact and correct mixtures to produce the optimum material for any use. The notes you are seeking may exist in the lab notes of the developemtn chemist who worked to get to the proper end point. The adverse effects to a manufacturer are complete loss of sale!

Most epoxies aren't actually formulated for a 1 to 1 mix. But, to make things easier for the people using the products, those who formulate for rod builders (and others) will add "fillers" to one of the components so that the final ratio comes out at 1 to 1. There is always a little leeway, but it's a very small percentage and this is why you often hear builders advising not to mix less than 3 ccs of each component. On a total 1 cc mix, being off a drop could throw you off by a double digit percentage. Being off by that same drop on a total 6 cc mix is a much smaller percentage.

Ralph O'Quinn is the only person in the rod building epoxy game that actually formulates his own products (Trondak U-40). He has written several articles in past issues of RodMaker that outline the technical side of epoxies and how and why they do what they do.

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Do graphite/epoxy rod blanks break down from environmental factors over time? If so, which environmental factors are the most significant?
Stop with the doors-car trunks-ceiling fans-teething puppies refrain. I'm wondering along the lines of heat, rapid temperature changes, sunlight, ozone, solvents, chemical fumes -that kind of stuff.

Carbon is a very stable material, able to withstand a very broad temperature range. However, heat above 200F can and most likely will damage graphite rod blanks. UV damages everything, but your graphite rod will fare much better than you will under many years of UV exposure. Harsh solvents like acetone and lacquer thinner can damage a blank but it would take a good bit more than a few wipes with a solvent soaked rag to do it.

All in all, those car doors you mention pose a far greater danger to your rod than temperature, UV or solvents do.

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