I’ve been struggling with 15min epoxy to mix, load and dispense quickly enough using syringes. It’s also been very wasteful as you reach a point where you are getting more air than epoxy when trying to draw it up into a syringe.
Also, with my current project being the first time I’ve injected internal fillets from outside the airframe, my holes were a little smaller than I needed.
Two simple solutions I’ve found:
(Before anyone rants about epoxy and exothermic reactions in deep vessels, I did a test and the BSI epoxy I’m using never even got warm - I’m working quickly and the whole lot was mixed and injected in under 4mins)
1) heat shrink tube as a flexible syringe tip:
2) measuring and mixing the epoxy IN the syringe: (no pic, as it takes two hands and there’s no handy photographer around)
I have 6ml syringes, so I:
Fold over the heat shrink to seal the end
I fill to 3ml with epoxy,
start the stopwatch;
fill with hardener to 6ml.
I use a thin coffee stirrer to mix the epoxy up and down and round and around till the colour is uniform
Then, insert the plunger and inject away!
I’ve found sharpening the coffee stirrer with a pencil sharpener helps get the mix action down into the tip of the syringe.
Also, with my current project being the first time I’ve injected internal fillets from outside the airframe, my holes were a little smaller than I needed.
Two simple solutions I’ve found:
(Before anyone rants about epoxy and exothermic reactions in deep vessels, I did a test and the BSI epoxy I’m using never even got warm - I’m working quickly and the whole lot was mixed and injected in under 4mins)
1) heat shrink tube as a flexible syringe tip:
2) measuring and mixing the epoxy IN the syringe: (no pic, as it takes two hands and there’s no handy photographer around)
I have 6ml syringes, so I:
Fold over the heat shrink to seal the end
I fill to 3ml with epoxy,
start the stopwatch;
fill with hardener to 6ml.
I use a thin coffee stirrer to mix the epoxy up and down and round and around till the colour is uniform
Then, insert the plunger and inject away!
I’ve found sharpening the coffee stirrer with a pencil sharpener helps get the mix action down into the tip of the syringe.