Geoff S Posted December 30, 2020 Share Posted December 30, 2020 ... because the manufacturers profit comes from what's thrown away (as it was always said about Colemans mustard and it's why I always eat all mine It's just that I've been using JB Kwik weld to glue in split cotters to use as anchor points for the rigging on my Sopwith Pup. At times I only actually use half (if that) of the epoxy I mix and it goes off so quickly (6 minutes to set 4 to 6 hours to cure) there's never time to find a use for the excess. Is it just me or is everyone afraid of running out and so mixes too much? Geoff Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted December 30, 2020 Share Posted December 30, 2020 Lesser of two evils Geoff, better to waste some than not get job done right. Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted December 30, 2020 Share Posted December 30, 2020 Whenever possible I put the epoxy on the job I'm going to use it on and mix it in situ, that way there's no waste. Warming it with a hair drier to wet it out thoroughly reduces the likelihood of trapped air. Geoff, why not use one of the slower epoxies, say 30 minute, so you can get more split pins fitted from one mix? Quote Link to comment Share on other sites More sharing options...
brokenenglish Posted December 31, 2020 Share Posted December 31, 2020 It's always better to leave a little unused, to provide a check that the adhesive has hardened properly, and to know exactly when it's sufficiently hardened, so that you can continue working. Quote Link to comment Share on other sites More sharing options...
Wingman Posted December 31, 2020 Share Posted December 31, 2020 I'm sure we all mix up too much epoxy - it's just a human thing- but it's a bit daft because it only takes between 10 and 30 seconds to mix up a new batch - and I keep saying that to myself when i have a large splodge left after doing a job Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted December 31, 2020 Share Posted December 31, 2020 Personally I tend to mix excess epoxy and then run round trying to find any other little jobs that need a little dab of epoxy. I think it's important though to mix enough to get that 50:50 ratio correct and avoid the never-set demons. If you don;t have any little jobs that need that little bit of epoxy, you can make a lovely filler with some microballoons, which increases the possible range of little jobs for that excess epoxy. Quote Link to comment Share on other sites More sharing options...
kevin b Posted December 31, 2020 Share Posted December 31, 2020 Throw away !!! I am always careful to try and mix the correct amount for the job and usually have other "little jobs" around to use any excess on. It's amazing what you can find that needs fixing ! As has been said, it only takes a few seconds if you need to mix any more. There again I am a Yorkshireman. Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted December 31, 2020 Share Posted December 31, 2020 Like leccyflyer I tend to mix more than I need because I've got a better chance of getting something near the correct 50:50 ratio that way. Even using the two-joined-syringe dispensers, I find that both nozzles never seem to start or stop at exactly the same time, so getting equal quantities of a tiny amount is very unlikely. Quote Link to comment Share on other sites More sharing options...
Toni Reynaud Posted January 1, 2021 Share Posted January 1, 2021 I was told many years ago to always mix half as much as you think you need and it will turn out to be twice as much as you actually need. Sounds like that's still true! Edited By Toni Reynaud on 01/01/2021 07:21:56 Quote Link to comment Share on other sites More sharing options...
Jason Channing Posted January 1, 2021 Share Posted January 1, 2021 Get some small accurate scales and you can mix1gm with no problems. Quote Link to comment Share on other sites More sharing options...
Wingman Posted January 1, 2021 Share Posted January 1, 2021 Oh dear! Quote Link to comment Share on other sites More sharing options...
Geoff S Posted January 1, 2021 Author Share Posted January 1, 2021 I must confess, when I started this thread it wasn't a 100% serious post., though the similarity between epoxy and the mustard profit theory has occurred to me before when I've had to discard unused adhesive. I do use some fairly accurate (well perhaps not accurate but with 1 gm resolution - not the same thing) to weigh larger quantites of epoxy - mostly WEST, the idea of weighing adhesive seems a bit OTT. The 50:50 mix doesn't seem to be super-critical and I've never had any fail to set. I've noticed the De-luxe Materials 4 and 60 minute Speed Epoxy I use only seems to differ in the hardener used. The adhesive bottles aren't identified as either 4 or 60 minute, only the hardener.is. Anyone know if that's the case? ie is it only the hardener composition that determines the setting time? Geoff Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 1, 2021 Share Posted January 1, 2021 I've certainly never weighed adhesive Geoff - I just put a semicircle of resin on a plastic surface and add a same sized semicircle of hardener in contact with it - ending up with a complete circle of epoxy, which is then thoroughly stirred, with a lolly ice stick, in both directions, until it is completely mixed, ready for use. Quote Link to comment Share on other sites More sharing options...
Wingman Posted January 1, 2021 Share Posted January 1, 2021 Geoff - yep I use the same bottle of DM resin with the two different rated hardeners - no problem. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 1, 2021 Share Posted January 1, 2021 I always mix by eye and have never had any problem but some laminating epoxies are supposed to be more critical. I don't know how much of this is coloured by having learnt this from repairers of full sized aircraft structures who took pains to measure extremely accurately so it could be as much to do with compliance and repeatable results than achieving acceptable results for general purpose use. I have a couple of identical small diameter polythene bottles which I use for laminating epoxy on my models - placing them side by side and squeezing resin and hardener into them to the same height from the storage bottles before mixing in a paper cup seems to work well. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted January 1, 2021 Share Posted January 1, 2021 A laminating resin I have used has different mix ratios depending whether you are doing it by volume or weight, so beware the densities of the hardener and adhesive may be different. This particular resin is sold with a choice of fast or slow hardener so it is only this that determines the speed. A. Edited By Andy Stephenson on 01/01/2021 14:14:42 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted January 1, 2021 Author Share Posted January 1, 2021 Posted by leccyflyer on 01/01/2021 11:36:24: I've certainly never weighed adhesive Geoff - I just put a semicircle of resin on a plastic surface and add a same sized semicircle of hardener in contact with it - ending up with a complete circle of epoxy, which is then thoroughly stirred, with a lolly ice stick, in both directions, until it is completely mixed, ready for use. That's OK for adhesives but resin like WEST is a liquid, a fairly viscous one but still sufficiently liquid for it to be mixed in a container (I use old cardboard yoghurt pots that are gradually filling with hardened epoxy and the scales offset the nett weight). So they are the ones I mix by weight - 5:1 for WEST, I think. Geoff Quote Link to comment Share on other sites More sharing options...
kevin b Posted January 1, 2021 Share Posted January 1, 2021 Martin. Mark the inside of the paper cup to measure. You will waste less adhesive and solvent cleaner than measuring out first and then having to clean the measuring containers. (no charge for the tip) Quote Link to comment Share on other sites More sharing options...
Steven S Posted January 1, 2021 Share Posted January 1, 2021 I mix mine the same way as "lecckyflier" except I mix it on wax paper. Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 1, 2021 Share Posted January 1, 2021 Posted by Geoff S on 01/01/2021 17:35:53: Posted by leccyflyer on 01/01/2021 11:36:24: I've certainly never weighed adhesive Geoff - I just put a semicircle of resin on a plastic surface and add a same sized semicircle of hardener in contact with it - ending up with a complete circle of epoxy, which is then thoroughly stirred, with a lolly ice stick, in both directions, until it is completely mixed, ready for use. That's OK for adhesives but resin like WEST is a liquid, a fairly viscous one but still sufficiently liquid for it to be mixed in a container (I use old cardboard yoghurt pots that are gradually filling with hardened epoxy and the scales offset the nett weight). So they are the ones I mix by weight - 5:1 for WEST, I think. Geoff Aye, but that's not adhesive, is it? It's a finishing resin. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted January 1, 2021 Author Share Posted January 1, 2021 Well it's used to stick dinghies together, which is where I first came across it, though with a bit of filler (glass spheres, carbon etc). I used it like that to build my 1 metre model racing yacht and to deck a 12'6" racing dinghy. It also sticks the 4mm ply disc that holds both the dummy engime and the 1.2kg of lead (with screws into the wood) in the aluminium cowl of my Sopwith Pup. But you're right, it's not an adhesive in the more usual definition despite being somewht sticky. Geoff Quote Link to comment Share on other sites More sharing options...
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