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Fibreglass resin catalyst - any easy thinners available? Answered

I am in the need to make a quick decision before the weekend.
A local shop is closing down and I was offer a massive amount of good quality resin for price that you could call stealing LOL
Only problem is that there is no catalyst included as the owner realised the container had a leak the stuff was long gone.
Buying the required amount of catalyst down here so I consider making my own.
For obvious reasons I won't go into the details of making...
Problem on my end is that the catalyst needs to be thinned down to 40-60% to prevent unwanted results handling and using it.
All the commercial products use thinners based on very hard to obtain organic solvents.
From what I could read they are added to prevent mis-use of the product, which means there might be other solvents that work for the thinning without affecting the resin or curing process in a negative way.

Big question: What type of easy to obtain solvent can I use for this without compromising the resin or curing?

And before anyone asks:
No I won't tell you - if you don't know what I am talking about you don't need to ask on how to make it as I won't tell.
And no again, I am not looking for ways to make the resin thinner - I need to dilute the pure catalyst to make it useable and safe.
My sole intention is make a good deal but unless I find a suitable thinner I won't buy close to 300 liters of resin....

Discussions

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Downunder35m

2 years ago

Ok, made some better progress :)
The pure catalyst can be thinned with MEK but only to about 60% catalyst and 40% MEK - Acetone is a no go here.
With this ratio the resin gets quite hot and the curing time means you need to very quick.
Also thick layers should be avoided due to possible overheating during curing.
100ml of resin only required a few drops of mixed catalyst this way.
But even going to a 50-50 makes the resin curing useless and very time consuming even if more catalyst mix is used.
At this stage I have to assume the commercial thinners also slow down the chaining reaction and add a little bit of flex to the cured resin.
Would not want to use my mix for structural parts under high stressed as compared to commercial products the cured resin is quite brittle.
And all the hassle and testing turned out to be a waste as the sold the lot after getting an offer he claims he could not resist :(
Better luck next time I guess...

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rickharrisDownunder35m

Answer 2 years ago

Oh well.

I kept a gallon of resin for several years , in the dark in the loft of the garage. One day i though of a use to find the whole thing had spontaneously cures and gone solid. Couldn't find a use for a gallon block of polyester resin.

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Downunder35mrickharris

Answer 2 years ago

Hmmm....
Sounds awfully familiar LOL
Had that a few years ago with clear casting resin.
Ordered 3 liters as it was cheaper than a smaller batch for the volume I needed.
Documents stated a shelf life of around 5 years if kept closed and in cool + dark enviroments.
The stuff blocked the veggie box of my fridge for little over a year and when I wanted to use some more it was rock solid throughout.
But another, smaller batch is now close to 6 years old and still "fresh" despite using a bit of it every now and then for projects.

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rickharris

2 years ago

http://www.homedepot.com/p/Klean-Strip-32-oz-Methy...

Not clear what this actually is but appears to be a solvent for Polystyrene resin catalyst - Unable to see anything on line re manufacturing/ changing properties.

Most of the catalyst I use is quite thick to make it easier to handle.

You could try a manufacturer and see if they will share information with you.

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Downunder35mrickharris

Answer 2 years ago

Well, that is the base material for the catalyst.
Was my first choice for the testing too...
It does work for thinning the catalyst so it is no longer a thick oil but when used like this the resulting, cured resin has trouble curing in time and it goes quite brittle when fully cured.
For the testing I mix a small amount of resin and let it cure in a plastic container at a thickness of around 3mm.
Using original catalyst the resulting disk is really hard and I struggle to break it by hand the next day.
If I use MEK as a thinner in my catalyst it takes about 2 days to cure and the disk just snapps or breaks into little crubles.
And yes, I tried the pure catalyst too and let's just say it was not such a good idea LOL
Acetone can be used to clean uncured resin so that was my next choice.
Works too as a thinner but for some reason refuses to fully evaporate from the resin.
Took about 3 days to loose the smell when warmed up and the result was more like plastic, still a bit flexible and giving under pressure.

The thinners used in commercial catalyst are mostly unavailable down here, at least in quantities that would not require a drum or 1000l container.
And they all require permits for buying them as they are quite toxic or harmful for the enviroment.
Even "basic" solvents like toluol, xylene or just chloroform are basically unavailbe to me in this country.

Will get back to the drawing board and try to find out where the danger line for the catalyst is and use as little thinner as possible to prevent the resin from going up in flames.
Maybe in smaller quantities the thinner will be able to evaporate before the curing is finnished or at least tot he point where the rest is gone within a few days.

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rickharrisDownunder35m

Answer 2 years ago

Good luck, I have always used commercial products in the past they are easy to get here in the UK.