Heating will substantially accelerate most chemical reactions.

Cheers,

Peter

 

From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au]
Sent: 23 August 2018 10:33
To: harryproa@yahoogroups.com.au
Subject: Re: [harryproa] Re:: Infusion epoxy

 

 

I don't know what you mean with "thick" infusions. But as I see it, the viscosity of the resin should be proportional to the time it takes to infuse a certain length. (The unit is Pa*s)..  So my guess is that the epoxy has thicker viscosity means that it needs needs to have longer potlife, or the size of the job / spacing between the inlets of epoxy in the bag has to be smaller. Otherwise the epoxy will not have time to reach every corner of the job before it starts to cure. So maybe a way to compare epoxies regarding "infusability" is to multiply viscosity with potlife?

 

On my first attempt of infusion I used the epoxy I had at my house, just a normal type for manual layup I guess. 45-60 min potlife, and felt pretty thick, like 20W50 motor oil. (Resin 1000 mPa*s, Hardener 100 mPa*s). To make it thinner, I heated the pot, and started the infusion. It was going slow. After a pretty short time (felt like 20 minutes, but I was busy) it stopped. The resin in the pot was getting really hot, so was already starting to cure. The resin had moved maybe 10cm in the job. I think that maybe because I heated it, the already short potlife had become even shorter.

 

On Wed, Aug 22, 2018 at 5:45 AM, '.' eruttan@yahoo.com [harryproa] <harryproa@yahoogroups.com.au> wrote:

 

| Both System3 and MAS epoxies are good products; you probably can't go wrong with either.

I get crap wrong all the time, so please call me on it, but, afaict;

system three's infusion resin is a by request item only.

MAS has no data sheets on anything.

When I asked Paul about infusion epoxy, he said use no blush, not the low v.. Why?

So, why is infusion epoxy such a boogy man?

Should we not know that one wants in an infusion resin with some range of cps and various modulous and other data points, and then comparatively shop in those ranges?

| I don't have any experience with uscomposites. If you go that route, I'd recommend the non-blushing slow hardener (assuming you have enough space in your schedule for the cure time). One should always prepare surfaces before new coats, but that said, not having blush in the first place is even safer.

Sure, but with II we don't generally have recoats? And cure times are not a big deal generally, I think. Even post curing should be easy i think.. Am I wrong?

| As for Oman's epoxyproducts, did you email Paul and/or look at the low-v?

I did email him, as noted. His web page drives me nuts, and his prices do too. Now I am a cheap ass bastard, but almost twice the price seems a hard case to make.

But perhaps 175 cps is worth it? I mean, is anyone actually infusing? Can one tell the difference between 400cps and 200? Basically every rando 'infusion epoxy' i can find is 400-500 cps.

| He'll give you as much detail as you'd like if you ask him a question.

The problem is I don't think I know enough to actually ask reasonable questions.

| The low-v is non-blushing, with a viscosity of 500 cps for the resin, 80 cps for the hardener, and 175 cps for the mix. That would be noticeably thinner than the 283 cps for the uscomposites mix.

| Though it looks like low-v costs almost twice as much as the uscomposites product, so would only be worth the price if a less viscous mix is important to you.

How would I know if it is important to me? Is it important to us? You are thinking about doing II too, right? Like, afaict, 283 is a dam low number. 175 is very impressive.

Its kinda like the core material. 200psi compressive strength is awesome. But is it needed? Will 100psi do?

Can I do most of the square meters with cheap 283 cps, and save the 175 stuff for thick infusions?

Rob, what do we need in an epoxy!?

What do we want in an epoxy!?

Or is this all covered in the plans? And I should wait till mine arrive?

 

 

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