hello,
Looking to buy some new epoxy resin in bigger quantity, 4-5L.
Have you had any good/bad experiences with cheap ''non-marine'' epoxy resin (ebay and others)? Are they similar in term of specs with only different stickers or not?

I have been buying epoxy from Newkem in Nowra for years. Usually in 2 kilo packs just for ease of use. Bigger jobs like laying up the deck on the fishing boat I used 5 kilo packs. I use digital scales to get the right mix, 5:1 by weight and as long as your accurate there will be no problems. It's well priced and probably as good as any of the boutique brands. Good enough for the local boat builders and fishermen.

I'd say an ebay cheap epoxy is too risky for a boat, especially when your life may depend on it. If you happen to know the seller, trust them AND have a track record of using the epoxy then maybe.
Now if your life does not depend on it then the only risk is the epoxy not setting correctly. That just means an awful mess to clean up.

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zilla said..
I'd say an ebay cheap epoxy is too risky for a boat, especially when your life may depend on it. If you happen to know the seller, trust them AND have a track record of using the epoxy then maybe.
Now if your life does not depend on it then the only risk is the epoxy not setting correctly. That just means an awful mess to clean up.

Is your opinion based on a bad experience with cheap epoxy?

I used big tins of Diggers epoxy from Bunnings many times and no problems. It has a spec. Sheet available.

I use hc 1000 from fgi in Ballina it's a 2:1 cost a bit more than their 5:1, I find it easier to measure and it doesn't seem to blush at all

resins aint resins weather ,epoxy or vynl ester resins are speced to do different jobs and there are many epoxy resins of varing hardness and curing times . SPEAK TO AN EXPERT that isnt someone on a forum i would rather pay a bit more and get a predictable result than save money and end up stuffing the job
comments on always weighing resins on digital scales are 100 %correct and if i catch my staff mixing resin without scales a lot of yelling results

thks! will have a look Newkem in Nowra

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woko said..
I use hc 1000 from fgi in Ballina it's a 2:1 cost a bit more than their 5:1, I find it easier to measure and it doesn't seem to blush at all

The Newkem epoxy is the FGI 5:1 stuff with a new label.

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boty said..
comments on always weighing resins on digital scales are 100 %correct and if i catch my staff mixing resin without scales a lot of yelling results

Be a little careful using weight to mix epoxy, some have a mix ratio by volume, and as it turns out, the two parts are different densities. Caught me out a couple of times before someone explained the issue.

If and when the epoxy fails catastrophically, only then will you find out if it was cheap garbage.

Even good epoxy can be rendered to crap if the mix ratios are not correctly adhered to and in fact the smaller the total quantity being mixed is, the more critical it becomes to accurately get the mix ratios correct.

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nebbian said..

boty said..
comments on always weighing resins on digital scales are 100 %correct and if i catch my staff mixing resin without scales a lot of yelling results

Be a little careful using weight to mix epoxy, some have a mix ratio by volume, and as it turns out, the two parts are different densities. Caught me out a couple of times before someone explained the issue.

always get the by weight data from supplier

I use cooking measuring cup to mix resin by volume

There's accurate and fanatic I have always measured by volume ( glad I don't work for boty I would send his blood pressure thru the roof, ) when I first meet epoxy digital scales weren't very common. I had some of the early west systems pumps that screw onto the top of the container, good for a while but didn't take long to get crusty and then the troubles start, read gooey sticky cheeses. since then I've used syringes or bottle tops for small amounts and an array of other disposable containers as the quantity increases. Without fail.
While on epoxy don't forget Ramonas tip about useing metho to clean up / thin epoxy, cheers

white vinegar is an even cheaper and safer clean up material; especially on the hands

Digital kitchen scales are ridiculously cheap these days. Also have a jewellers digital scale for mixing tiny amounts of glue.

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cazou34 said..
hello,
Looking to buy some new epoxy resin in bigger quantity, 4-5L.
Have you had any good/bad experiences with cheap ''non-marine'' epoxy resin (ebay and others)? Are they similar in term of specs with only different stickers or not?

I changed from using West System 105 to Trojan 500 series
trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51-2/
and can't tell the difference .
You can get it from them through eBay as well.

Yeah I use the Trojan stuff as well.

I have used West 105, ATL ADR 246, ACME 521, FGI, Boatcote, Epiglass, Norglass and more and I can't remember any that have ever failed. In building 4 boats I have never had a mix not go off - so after about 10000 mixes I would say you are pretty safe using a reasonable epoxy for anything. Weighing or volume its all fine, just be careful and chuck out a mix if you lose count.

If you want a lovely clear finish then use a nice expensive epoxy but my advice would be to buy Trojan or similar. Read the Gougeon brothers book or remember some simple advice. Mix small batches
Be sequential when mixing - don't talk unit the hardener is in.
Stir well for a minute or two
Use the correct filler - micro-balloons for low strength and fillers, microfibres/silica for glue mixes.
Change the the filler/glue thickness depending on the job. Less thickener for larger flatter surfaces, thicker for thinner, rougher surfaces.
NEVER EVER change the ratios. ALWAYS use the correct ratios. Change pot life by cooling or heating or changing hardener.
Wear a mask when mixing in thickeners.
Don't re-use containers. Collect 2 litre milk containers and cut the top off, the bottom makes a great mixing container.
Always wear gloves - I use latex but some use nitrile (I use nitrile when spraying).
I don't clean up brushes, I can't make them good to use again. I clean up my cove tools with a heat gun - epoxy softens when heated strongly.
Once you start with epoxy, you have to keep using it - don't use flowcoat over the top. Paint with epoxy primer then topcoat.

Epoxy is a great resin - do some small jobs and keep your eyes open.

thks a lot, really helpful,
about gelcoat and epoxy bonding, I recommend this video:

Regarding brushes, you can re-use them if you wash them in acetone straight after applying the epoxy. I've been using this method for a while, it lets me usually get about 5 uses out of a brush before I try to push it too hard and the epoxy sets too much before I wash the brush.

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nebbian said..
Regarding brushes, you can re-use them if you wash them in acetone straight after applying the epoxy. I've been using this method for a while, it lets me usually get about 5 uses out of a brush before I try to push it too hard and the epoxy sets too much before I wash the brush.

Or save your acetone and use cheap brushes instead ?
The most expensive brushes I use cost about $1.50 each from
www.ebay.com.au/itm/1-5-Disposable-Fibreglass-Brush-38mm-Bulk-pack-of-12-FREE-FREIGHT/141373541926
and that only if I run out of my usual 50c ones which I buy from Chinese sellers on ebay.

I pay around $8/ltr for acetone and would cost me at least 80c per washed brush so my brushes are just not worth cleaning.
The mixing pots I use are round 500g takeaway food containers so by leaving the brush to set in a dirty pot the next day when the brush is solid it lifts the old epoxy clean off the pot so the pot is clean and ready to use again.

It's true Harb, you need to figure out if this is right for you...

But I use small brushes, and a jam jar of acetone with a tightly fitting lid. It's more economic for me to wash my brushes, than to throw them away. The one jar can wash lots of brushes (20?) before the acetone goes bad.

www.sanded.com.au/collections/surfboard-resins/products/surfset-flex-clear-3-litres

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sanded said..
www.sanded.com.au/collections/surfboard-resins/products/surfset-flex-clear-3-litres

Hi Sanded, looking at this product, I have some applications where some "flex" would really be an advantage, since generally epoxy is often pretty hard and brittle.

Can you confirm this Surfset Flex is also a "normal" structural epoxy rather than specifically being a coating intended just for surfboard cosmetics?

West System Claim this to be very flexible
Has anyone had any experience with it

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Capt_Newmo said..
West System Claim this to be very flexible
Has anyone had any experience with it

Sailing Anarchy fix it section raves about it. They are the main sponsor of that section but I'm sure it's good.

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Karsten said..

sanded said..
www.sanded.com.au/collections/surfboard-resins/products/surfset-flex-clear-3-litres

Hi Sanded, looking at this product, I have some applications where some "flex" would really be an advantage, since generally epoxy is often pretty hard and brittle.

Can you confirm this Surfset Flex is also a "normal" structural epoxy rather than specifically being a coating intended just for surfboard cosmetics?

Hi Karsten

Sorry I missed your comment this resin has the same structural qualities to other epoxy resins, the main difference we do an acrylic/epoxy mix which gives the flex. (think of perspex)

We have all the test results which we did with epoxytesting.com in their lab and it compares with west systems, nuplex etc..

Cheap is cheap. Quality is quality.
Neither word belongs in the same sentence.