Epoxy resin has not set off - what to do.

[Neeves]

&-8 weeks ago made up some epoxy at the 2:1 instruction on the label. I wetted out some fibre glass. It did not set off. We have been away for 6 weeks - some of it has still not set off. It has been cold in Sydney, its winter here and night time temps get down to 5 degrees, and as my workshop is 'underground' it is cold.

What to do?

I am reluctant to scrap it all. I have thought of over coating with a new layer of resin, this might (or might not) set off - but even if it does set off the impregnated glass will still be encased in 'sticky' (to the touch - it does not stick to your fingers) low strength resin. I can leave it, put it in the sun, just be patient.

Why it did not set off...? Its been cold, the resin is not fresh, at a 2:1 mix even an idiot would not get it wrong.

Suggestions, to remedy the issue.

Jonathan

 

[Gsailor]

Add heat is best solution IMO.

As you allude - applying more resin or catalyst may only react with partial lay up.

Hopefully heat will ensure entire layup will cure.

Let us know what you do and how it works if possible - it is good to learn from others.

 

[VicS]

Add heat is best solution IMO.

As you allude - applying more resin or catalyst may only react with partial lay up.

Hopefully heat will ensure entire layup will cure.

Let us know what you do and how it works if possible - it is good to learn from others.

It is not a catalysed reaction like a polyester resin.
Heat is the only option.

 

[Gsailor]

It is not a catalysed reaction like a polyester resin.

Didn’t know that - thanks.

Does that mean heat won’t help either? I am not a scientist as is obvious.

May I ask... I have a gallon of epoxy somewhere and the small bottle (that is not a catalyst , as I have just found out)...

does that mean the gallon of epoxy and small bottle of additive (what does the additive do?) may still be useable ? - probable age since bought is 10 years.

 

[VicS]

Didn’t know that - thanks.

Does that mean heat won’t help either? I am not a scientist as is obvious.

May I ask... I have a gallon of epoxy somewhere and the small bottle (that is not a catalyst , as I have just found out)...

does that mean the gallon of epoxy and small bottle of additive (what does the additive do?) may still be useable ? - probable age since bought is 10 years.

Yes heat should help. I added that to my post while you were typing.

Neeves may have used a slow hardener which is unsuitable at temperatures below 16C

A small bottle of something sounds more like the catalyst for a polyester resin. With epoxy it is a reaction between the two components mixed accurately in a specified ratio.
With polyester the proportion of resin to catalyst can be varied to vary the gelling time and to suit the temperature eg



Unmixed epoxy keeps well but polyester does not both components deteriorating.

 

[B27]

I quite often apply heat when using epoxy. A hot air gun or IR light.

If it hasn't set in 6 weeks then I suspect it needs to be binned, it may be compromised by damp or something?
The hardener component of many epoxy kits does seem to degrade over time, developing a strong smell.
There are many different 'epoxies'.

 

[The Q]

Yes many versions of epoxy, the most extreme version of epoxy I used was a 13 parts resin 7 parts catalyst mix.. mind you that was a special mix for Saudi, to slow reaction time to 20 minutes. Conventional mix epoxy doesn't last seconds in 50C.
In the UK epoxy or polyester, unless its mid summer, I add heat, normally a 2kw fan heater to blow over the surface of the item warming it before and through the application of the resin.

 

[Neeves]

I'll try heat - we had a cold front come through overnight but daytime temperatures are forecast to maybe reach the mid 20s later next week. I'm making fibre glass panels to convert to lids for open lockers and I've laid up on black, construction, polythene sheet. The sheets are relatively easy to move. If that fails I'll use a hot air blower heater.

Normally the problem we have is that the epoxy sets off too quickly, because its so warm. Be slightly distracted/interrupted and the resin starts to smoke. I was being complacent and had not realised that low temperatures are equally critical.

I will post the results - its very frustrating when people give advice but the application of the advice by the OP is seldom confirmed.

Jonathan

 

[saxonpirate]

All of my work has been with SP Systems Epoxies.. that's back a few years now when working professionally in yacht construction. The golden rule then was 'don't use below 10C'. Epoxies, like all technologies have moved on, and I believe now that SP market a product that can be used down to 5C.

As for re-energising the epoxy that appears not to have set, you may be lucky if its still tacky, thus enabling a chemical bond to form with a new mix. I've done this myself in the past on a couple of occasions and got away with it. As others have mentioned though.. a helping hand with some heat won't go amiss.

The link below is linked to West Epoxies, but none the less it gives some good insights into cold weather use of epoxy, and some tips when things go wrong. It may well be useful to you..

How to Work With Epoxy in Cold Weather - Epoxycraft

 

[Boater Sam]

I would not use 10 year old material for anything important. Unmixed resins have a habit of absorbing moisture from the air over time.

 

[Refueler]

&-8 weeks ago made up some epoxy at the 2:1 instruction on the label. I wetted out some fibre glass. It did not set off. We have been away for 6 weeks - some of it has still not set off. It has been cold in Sydney, its winter here and night time temps get down to 5 degrees, and as my workshop is 'underground' it is cold.

What to do?

I am reluctant to scrap it all. I have thought of over coating with a new layer of resin, this might (or might not) set off - but even if it does set off the impregnated glass will still be encased in 'sticky' (to the touch - it does not stick to your fingers) low strength resin. I can leave it, put it in the sun, just be patient.

Why it did not set off...? Its been cold, the resin is not fresh, at a 2:1 mix even an idiot would not get it wrong.

Suggestions, to remedy the issue.

Jonathan

How Epoxy Resin Works

This may help.

Personally ? Slow heat ... get area around the items steady up to 15 - 20C and leave for a few days .... as the heat needs to permeate all way through - not just surface.

Epoxy is tricky ... you can use a hair dryer to thin and get epoxy to seep into cracks etc. - but it also speeds up setting. Its an old trick with Carbon Fibre tubes etc., Spread epoxy along the split .... heat with hairdryer - then quickly wrap with tape / clingfilm to create smooth surface ... once cured - remove clingfilm ...

 

[penfold]

If the component is small enough put it in the oven on the lowest heat(usually 60-80c) for an hour or so; if too big make a hot box out of cardboard and a heater(convection or fan) but keep an eye on the temperature as heater thermostats are rubbish and it may set itself alight.

 

[PCUK]

Personally I would scrap it and start again rather than possibly wasting more epoxy trying to retrieve it. In cold weather I use Halogen work lights to warm the area and have found these to be the very best solution. For small items putting them in a small "tent" with a tube heater also works well.

 

[Rappey]

Ive found that west epoxy may fail to work once its a few years old. Its the resin thats the problem .the catalyst seems to work regardless how old.
I mix a bottle top amount as a test to see if it still works. When it doesnt it sets like a thick plyable wax.
Ive not had problems at cold temperatures, just take a lot longer.

 

[lusitano]

Epoxy also very sensitive to humidity as well as temperature. Read the label !

 

[graham]

With epoxy resin it goes off quickest if you get the ratio of resin to hardner exactly right and mix very thoroughly.

This is different to polyester where extra hardner(catalyst) will make it go off quicker.

Suspect the temperature is the problem and or the old stock issue.If whatever your glassing requires the strength it may be best for peace of mind just to bin it and start again.

 

[Bobc]

Hairdryer

 

[Neeves]

My desires to retrieve are because I'm using a heavy duty fibre left over from building our transom extensions. I've use all the glass and have plenty of resin. I don't want to buy more glass - if there is a fix. I know, or think I know , that actually the rest of the resin/hardner is alright as some of the glassed resin is like a rock but other parts, of the same glass and the same resin, are still soft and slightly sticky.

I've made up similar panels in the past, with success.

I'm making 2 x 500mm square panels with 50mm vertical edges, (imagine a tray) which will form lids to open topped lockers. Nothing that will demand serious strength. I'm willing to persevere down the route that seems largely the universal advice here:

Apply heat, or warmth.

Its been unusually cold in Sydney this winter, this morning it was 8 degrees (and my underground workshop enjoys no sunshine) but we are promised a couple of day time temps of 23/24 - and if this materialises I'm going to take advantage by placing the 2 panels on concrete warmed by the sun with black polythene sheets on top of the panels - a sort of shallow. black tent.

I've got my fingers crossed.

Thank you for all the advice - cold is not normally an issue here - the problem is usually (too much) heat and we have resins designed for heat, but not cold.

Jonathan

 

[William_H]

My desires to retrieve are because I'm using a heavy duty fibre left over from building our transom extensions. I've use all the glass and have plenty of resin. I don't want to buy more glass - if there is a fix. I know, or think I know , that actually the rest of the resin/hardner is alright as some of the glassed resin is like a rock but other parts, of the same glass and the same resin, are still soft and slightly sticky.

I've made up similar panels in the past, with success.

I'm making 2 x 500mm square panels with 50mm vertical edges, (imagine a tray) which will form lids to open topped lockers. Nothing that will demand serious strength. I'm willing to persevere down the route that seems largely the universal advice here:

Apply heat, or warmth.

Its been unusually cold in Sydney this winter, this morning it was 8 degrees (and my underground workshop enjoys no sunshine) but we are promised a couple of day time temps of 23/24 - and if this materialises I'm going to take advantage by placing the 2 panels on concrete warmed by the sun with black polythene sheets on top of the panels - a sort of shallow. black tent.

I've got my fingers crossed.

Thank you for all the advice - cold is not normally an issue here - the problem is usually (too much) heat and we have resins designed for heat, but not cold.

Jonathan

I would guess that the air temp of your workshop remains low from min 8 without heating even though official max temp gets to 23/24 for just a short period during the day. I hate winter but it is nearly over. ol'will

 

[Neeves]

I don't mind winter but I used to spend the week between Xmas and New Year ice climbing in Glencoe or Nevis and then the following week Loch Aan in the Cairngorms also ice climbing. Both in tents well above the snow line. I do confess winter seems to be colder than I recall in my youth - and the setting of resin is an issue that never occurred to me when climbing

It has been warmer today but the temps are going to drop overnight. I had the 2 pieces out in the sun but I suspect for insufficient time (and then the cold tonight might unmake my efforts).

But you are correct - my workshop takes 'summer' to warm up and has no heating - one reason being - its huge. I did contemplate building a cat in the workshop, its plot width, 15m long, until I realised I could not remove the hulls once built.

Jonathan