nightstalker101,
If you let the Scouts wait until they finish in two or three groups, you may be able to make a single set of epoxy tubes (2.5g each part) last. Each emitter takes about as much as what you would see in a dot that is made up of maybe two cubic millimeters (or less). If you have one of those little applicator sticks that come with the epoxy tubes, you just need to get a little bit on the end of it, and apply a very thin coating on the bottom of the slug. The P7 emitters would take maybe twice as much as what would actually coat the bottom of a P4 emitter. I would reccomend that you be the one who does the epoxy work, or train another leader. I guess maybe let some of the older Scouts try, but the ones that do not have the patience or maybe the motor skills, just ask that you do that one part so it the emitter will stay, and not burn up for having too much of a layer. If each emitter is done properly, then I think that you would find that you will have much epoxy left for many projects down the road. I attached 18 old K2s to a heatsink with the two 2.5g tubes with plenty to spare. I may have used the same set of tubes to do the second 18 K2 project.
Maybe a second set could be had on hand just in case of an emergency, or when you want to have two groups work at the same time. I can see someone push hard on the plunger of Part B to get some out, then they try to do the same for the easy-flowing Part A, and it squirts out like a gram worth of that expensive epoxy. I can especially see an adult do such a thing.
If you are able (as it depends on the project), you can set the heatsink in a shallow tub of hot water. For my odd project (two large heatsinks with 18 K2 emitters on each), I was trying to epoxy several emitters to a single, large, finned heatsink. I made a very shallow bath of hot water and set the heatsink in there. The heat conducted through the metal fins to the base where the LED emitters sat. The base got pretty warm and stayed warm for a long period of time. The epoxy set pretty quickly I believe, but I let it sit for an hour afterwards anyways. You may be able to do something similar if you are trying to epoxy an emitter to a removable heatsink (like a single emitter heatsink for a Maglite). Your results may vary (I am not sure if any steam or added humidity would affect the process).
I would like to say that your troop is the luckiest in the world for each child to have the opportunity to build a high power flashlight (or mod a flashlight). I dream that I could summon the funds to have my local troop do something similar. When I participate and help out, I usually have the chance to show off a few of my own creations. I usually grab the interests of several Scouts, and they often come to me to ask to borrow a light. One of them likes to experiment with making lanterns and modifying flashlights, but he has yet to dive in the LED world (just incans). I could never stand when I see one of them try to navigate in the dark with stock mini-mag or comparable (or nothing). I wish that I could afford to buy them all atleast a built light that is pretty durable and of high quality (the Romison G2 would be great I think). :thinking:
Can I ask what you have in store for the Scouts? Is it a DD mod of a simple light, or is there any sort of extra electronics? I am assuming that you are using the P7s for the leaders' mods (a basic 3 C or D Mag or similar). Please tell! If you do not mind explaining, it could be a relatively cheap project to be replicated with other non-enlightened troops. It would put the single 5mm LED, resistor, and 9V battery project to shame! Have fun and good luck! Thanks. :twothumbs
Cheers,
-Tony
It would be neat to see images of some of the finished products, especially the P7 Mags. :rock:
Well, that happens. Now, I may have to re-think such a project for our troop. Hmmmm. :thinking: Again, have fun.
