heating araldite

I've just glued some balance weights onto the wheels of my 5"g loco. They are held with capheads as well. Calculated centripetal force is very low. When the Araldite has set enough for it not to be runny I'm considering heating them up a bit to speed up curing. I'm led to believe this makes it stronger as well. Question is how hot, don't want to overdo it.

Keep it below70°C, Duncan

MichaelG.

I've used an electric fan oven at 60C without any problems. I wouldn't risk going any higher as they generally don't have an even temperature throughout. Some have a lower setting which should be super safe.

John

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If you heat it too much before gelled there is a possibility of losing some of the epoxy from the joint, unless it is in a pocket so the epoxy can't escape. If genuine Araldite 24hr Cure at 25-30 C for 24hrs and then post cure at 80 deg C for 8 hrs.

Emgee

Duncan,

Although this is specific to the '2011' products, it should give you a reasonable idea of the time/temperature relationship.

Despite the mention of higher temperatures ... my benchmark is still "below 70°C " ... Higher temperatures can cause bubbling and browning, both of which are counter-productive.

MichaelG.

Thanks. Now that it's not runny I've just carved away the excess. I'll leave it for 24 hrs before heating. In the meantime I've got a thermometer in SWMBO's oven to check the temperature. Can't open Michael's link, it just times out.

Michael, my recommended 80 C is for post curing after 24hrs at 25-30 C and is well below the cure temperatures for 2011 in your link. I do agree that if heated to higher temperatures before gelling then you may get bubbling and a brown appearance, the discolouration isn't a problem but any bubbles will certainly cause a weakness in the joint.

Emgee

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We're in the same 'ballpark'

MichaelG.

It's an exothermic process and the rate of reaction increases with temperature. It also becomes runnier (initially) if you heat it up, so once you've got the glue loaded up onto the target, heating it gives a nice smooth and shiny finish if you can allow for it also becoming runny for a short while. Finally, the result of heating is for it to set more quickly. Funny stuff - but very handy for some jobs!

to get it to flow into narrow gaps I use a hair drier ( got no use for it otherwise). Works well for wing joining tubes in model gliders .

Generally I just put in a plastic bag on top of the hot water tank and leave overnight. If you ever want to get it off heat to about 200 and it softens. I only use the 24 hour stuff as the 5 minute tends to soften and flex a bit aftera few years.

It is not a very stressed situation. You could just leave it to set and cure at room temperature.

Just an update, after 24hrs cure I cooked them for about 10hrs in the oven at 60.

All set nice and hard, excess could be carved with a sharp chisel. Thanks to all respondents.

Edited By duncan webster on 15/05/2016 22:03:51