Thanks a lot PilotPTK you cost me $40.

$40 for glue? You have to be kidding me.

Actually thanks for letting me know about Wakefield Deltabond 155. At first it seemed crazy to even think about spending that much on glue but after spending $120 on emitters I started thinking about what it would take to really get the most out of them. It does seem that this is as good as it gets and orders of magnitude better than others.

Now that I have a lifetimes supply I have a question for anyone who has used this stuff. I have seen different answers to the shelf life. One year to three years. How long do you think it will be good for? Would it be possible to store it in a way that makes it last longer? I would hate to use only a tenth of it and have it stop working.

Also does anyone know if it’s possible to squeeze some out into different containers so I could sell smaller amounts? I’m sure there are some people who would like a years supply but don’t want to pay $40.


How much is in a tube/package/bucket?

It’s two 3oz tubes. You mix them together 50 50. From what I read it’s close to being as thermally conductive as the copper or aluminum itself so it’s like bonding the copper stars directly to the aluminum pill. I figured that if I was going to be spending big bucks on direct copper emitters it makes sense to get the most out of them.

Squeeze it into small syringes… they are legal if they don’t have sharp points. You can get “oiling syringes” at most hobby stores.

Good idea.

BTW, this stuff has a thermal conductivity of less than 1. Copper is around 400 times better…

who lies? :slight_smile:

Well however it works or how the numbers work according to people who are experts it’s the best around and makes a big difference over using the other stuff.

Check out some of the thermal pads made by companies like Laird.

Panasonic makes some wicked ass thermal interface materials with 4 times the conductivity of copper (almost as good as diamond): (as low as $15 at Digikey)

I would guess you still have to glue it down somehow.

Sometimes good enough really is good enough (and sometimes, good enough is better). I'll stick(lol, pun!) to the JBWeld for aluminum pills and solder for the brass & copper ones.

They are conformal and designed to fill gaps, etc. Most have a sticky side or two…

now we are talking

Note that some of these materials are VERY thin (like 17 microns). You probably want to use the thicker ones in commercial flashlights (due to machining quality). The 0.1mm thick Panasonic pads have around twice the conductivity of copper (700).

i see what you mean

In a real-world flashlight application, measuring how much light comes out the front, how much difference is there between the worst thermal compound - say, jalapeno cheddar cheese dip - and the mediocre - cheap white silicone-based paste - and the best - diamond paste? Is it measurable? Is it noticeable with human eyes?

The pads have been discussed quite a bit as well. They are good but again you still have to somehow keep the emitter in place and there is a better alternative.

Ultrastick Phase Change Thermal Interface Compound 47.5 gram bar

I am far from any kind of expert and I am just going on what I have read from experts. But this is supposed to be really good. I guess the reason is that it fills in any tiny air gaps that act as insulation that doesn’t happen perfectly with pads or even the epoxy but the epoxy works the best if you need to glue it down.

I was thinking the 0.1mm PGS would work well. I wonder what the “handling precautions on pg.380 are? The datasheet stops at pg.379. Probably tells you that it is carcinogenic and it breaks apart like dried flower petals. :smiley:
Seriously though, putting PGS between the star and pill would not need adhesive and should produce measurable results compared to bare copper on aluminum or any silver thermal compound.

thats what i was thinking, but i would prefer a little thicker, i wonder if it stacks well

It’s been measured in temperature and temperature does play a role in light production vs heat production and stress on the emitter.

I noticed one graph that compared fugic and arctic silver etc with toothpaste and the toothpaste did as well as the others. Still better than nothing. It wasn’t until you jump up to the really good compounds that they see a big difference.

I am not an expert in any way shape or form and I have no way to test this myself. But I spent a fair amount of time researching it and what I read convinced me that it was worth it. Probably not unless you are planning on really overdriving an emitter though. I’m planning on making some really large heatsinks and drive some new generation emitters as close to max as possible. 7amps for a MX-L2 on copper for starters 5 amps for XP-G2’s and I’m not sure how high for MT-G2’s. All it would take is frying two MT-G2’s to have it cost you what this Wakefield 155 costs.