Don Fry Posted November 7, 2021 Share Posted November 7, 2021 No, it disintegrates, or more accurately, degrades. It works for Two stoke exaust, but is challenged, or copes. For Four stroke exhaust, it might cope. Perhaps for a time. Pushing your luck. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 8, 2021 Share Posted November 8, 2021 JBWeld copes with over 250deg C I think? How hot does a four stroke get? Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted November 8, 2021 Share Posted November 8, 2021 Plus one for JB weld which easily copes with temperatures of four stroke exhausts. I used some when the silencer strap on a Laser 155 broke during a show and the hole in the head got considerably enlarged due to the loose silencer rattling about. Fixed it a treat. Quote Link to comment Share on other sites More sharing options...
Christopher Wolfe Posted November 8, 2021 Share Posted November 8, 2021 After using various epoxy adhesives over many years my observations are that 5 minute epoxy 'dries' to a rubbery compound that slowly deteriorates to a crumbly yellow mess. Quite useless for building a model aircraft unless one predicts a short life expectancy. Traditional slow cure epoxies are are another matter. I still have models built over 25 years ago using 24 hour Araldite to secure the engine bearers and bulkheads and the bond is just as good as the day that I built them. Sometimes it pays to be patient and wait for the glue to cure Araldite Chris Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted November 8, 2021 Author Share Posted November 8, 2021 1 hour ago, Christopher Wolfe said: After using various epoxy adhesives over many years my observations are that 5 minute epoxy 'dries' to a rubbery compound that slowly deteriorates to a crumbly yellow mess. Quite useless for building a model aircraft unless one predicts a short life expectancy.. . . Well, there's certainly a lot of different experiences in this thread. Up until a few years ago I used individual tubes of 5- or 10-minute epoxy (can't remember which) of a well known brand (also can't remember which!), and I've got models up to 20 years old which show no deterioration of the epoxy, which I normally used only for firewall and wing joiner/main spar joints. About three years ago I started using an own-brand twin-syringe 5-minute epoxy from our local model shop, and never had any problem with it -- the residue on the mixing tray was always hard/brittle. It's only during lockdown, using mail-order supplies of Devcon, and then Gorilla, that I've come across this rubbery issue. Quote Link to comment Share on other sites More sharing options...
conrad taggart Posted November 8, 2021 Share Posted November 8, 2021 Horses for courses = some excellent testing done here ? Quote Link to comment Share on other sites More sharing options...
George P. Posted November 13, 2021 Share Posted November 13, 2021 I decided to epoxy some horns into control surfaces today but did not have space on the building board to fit a wing panel. It was 13 degrees in the garden and it had felt very mild in my shirt top when I painted the shed earlier in the morning and so I set up a table and began the process. A horn was glued into position using Devcon 30 minute but I was surprised to find it had not set when I returned over an hour later. I had mixed it correctly. Nearly four hours later I lost my nerve and decided to pull the horn out while I still could and clean up so I could try again another time. Was it too cold for the Epoxy? I have read many accounts of people working in sheds in the midst of winter with no problems. Do you think it would have cured if I had taken it inside and left it? OR Is it just an unlucky batch of POXY Epoxy? Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted November 13, 2021 Share Posted November 13, 2021 Not unusual. I have some 30 min of unknown brand which I only use on horns and gives the same problem; even in a warm shed I can be looking at 2 or 3 hours. Gentle heating during mixing helps. Quote Link to comment Share on other sites More sharing options...
George P. Posted November 13, 2021 Share Posted November 13, 2021 2 hours ago, Martin McIntosh said: Not unusual. I have some 30 min of unknown brand which I only use on horns and gives the same problem; even in a warm shed I can be looking at 2 or 3 hours. Gentle heating during mixing helps. Thanks, Martin. Given your experience, I probably could have just left it to set. I will probably send off for some new epoxy anyway to be on the safe side and, now I know it is not unusual, I will give it longer to set next time. Quote Link to comment Share on other sites More sharing options...
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