If Fujik is just white silicone, why not just use high temp silicone from the auto parts store?
From what I read on it, it's just white silicone, so why not use the black automotive silicone made for 500+ degrees. In fact they have some silicone for up to 800 degrees, so why not use it?
If your talking about using it for a TIM, then it’s because it has absolutely horrendous thermal properties.
I’ve never used Fujik but if it’s nothing but silicone I guess I’m lucky.
BTW, Permatex makes a Copper RTV sealant Permatex Ultra Copper it can often be found in Wal-Mart.
Well, I hope Fujik is okay, cause that’s what bought.
As long as the curing agent is not acidic, I would think that it would be fine. The major difference between regular silicone and electronics grade silicone is that the latter uses a curing agent that is safe for electronics. The acetic acid used as the curing agent in most household silicones can damage circuit boards.
If you're just using it to pot the driver, the thermal inefficiency of the compound shouldn't be a big issue as long as it conducts better than air. As long as it is better than air, it is better than using nothing.
Someone please correct me if I am wrong as I am definitely no expert on this
Edit (4/4/2014): It was explained to me later that acetic acid is a by-product of the curing process and is not itself the curing agent. I said I was no expert right? 
I just use Fujik because I know how it will behave. For all I know Sikaflex polyurethane would work. It sure is sticky.
here is some information from another site, you could even use cheese, its not bad but its not great
This is a very interesting read. From the moment I arrived here, I only read “just use Fujik.” I just assumed there was extensive testing already that showed it was head-and-shoulders above anything else.
If there is any other information on this, I would love to read it.
Just tested this on copper pipe with a 1” length of copper braid to wick heat from 80W hog leg iron to copper pipe. I won’t be buying Fujik! Within seconds you will pull test probe [finger] off the cured copper silicone. No smoke, fumes, fire or thermal cloud produced. Curing agent did not affect or stain the copper.
BTW, for the record, both the Permatex which contains copper and Artic Silver 5 (TIM) which contains silver; are totally NON electrically conductive. This was tested with my Fluke and backed up by finest quality HF tool box meter.
The Permatex was used to repair Frigidaire glass top stove where burner assembly had fallen loose where factory silicone glue had failed. That $3 tube of Permatex saved me $800 bucks in repairs and service calls. I wont’ be buying Frigidaire again!
Some, Mayonnaise and Mustard work better than some commercial compounds.
(I use “silicone transistor grease” from a tube I got 40 years ago, not the best but probably not bad either)
Read the roundup here: http://www.hardwaresecrets.com/article/Thermal-Compound-Roundup-January-2012/1468/1
Fujik is nothing short of underwhelming with a rating of 0.88W/m.K
Interesting chart Dchomak…. so if I pour chocolate into my flashlight it’s worse than using no thermal grease. Good to know :bigsmile:
You can use toothpaste instead https://budgetlightforum.com/t/-/5625#comment-115989
What few people seems to know is that most of these companies rebrand and rebrand so you will get identical results with many different thermal greases. Shin-Etsu Japan industrial greases are rebranded and successfully sold by companies, while those branded shin-etsu do not sell even if the reviews are good.
Yeah…keep the nutella out of the processor and you should be fine:D
Mayonnaise on the other hand 
Interesting, so as a guy new to modding, its looking like Miracle Whip has one other little known use. It even may function as a lube/greaser to the threads every time the flashlight heats up! I’ll always have a backup supply of yellow mustard just in case someone eats my “thermal grease”.
Whoa… hold up. All the “weird” recommendations - toothpaste, chocolate, mayo etc… they ONLY work as long as they’re not dried.
I’ve actually tried toothpaste, worked well initially but within a couple of weeek, blew the XML. Very clear and visible burn on the emitter. And this was when XMLs were $10 or something.
So take care using those advice. 
Stick with CPU thermal grease at least, they don’t dry out for a long time and are dirt cheap.
Thanks, I’m just joking around though, not going to Miracle Whip (or mustard) my lights Oh and chocolate you can use only to fry the emitter by the chart.
Would like to see people’s opinions for the one that works well and cheapest + non-toxic one though.
Irony: flashlight works best with dark chocolate. 
It’d be nice to see the performance of those $1 thermal grease on ebay/DX/BIC/FT compared to the chart.
I’m talking about some of these:
http://www.buyincoins.com/s/thermal-grease_s-price_ASC.html
By own eperience, they do work quite well, in fact much better than Fujik (of course), but still I do wonder how they fare against expensive Arctic Silver and the likes.
If they at least reach mustard or cream cheese level, I’m quite satisfied. :bigsmile: