Anybody know of any tutorials, videos or how-to’s on Potting drivers? Thanks.
I wrote this the other day:
I am using copper RTV mixed with 400 grit silicon carbide. I sometimes put in a bit of 2000 grit aluminum oxide as well.
I wet the silicon carbide with a drop of isopropyl alcohol. I use a small dowel (3mm diameter maybe) and knead by spinning the atv into the silicon against the side of a small glass dish. I then brush a very small amount of silicone oil into the driver cavity(helps in case it needs to be removed) and coat any contact surfaces with contact grease. Then when I press in the driver the potting material squishes out from the contact between driver and the driver lip on the host. I don’t count on this connection for electrical contact though. I make sure there is good connection on the visible side of the driver with a retaining ring or sometimes the battery tube. This mixture is not permanent and can be cut into as you can see in the picture above.
Potting like this really helps stabilize the output for the first 2 minutes especially on small lights. The first light I tested was an olight s30 modded with an fet driver. Without potting the output dropped much after 30 sec but held on much longer after potting. The next light I tested was a convoy s2+ with nichia 219c and a 4.2amp(12pcs amc7135). Definitely a noticeable difference! After the first 2-3mins I’m not sure how much it helps though.
What driver are you potting and in what light? Each can affect the choices made such as whether to pot before/after/both installing the driver. Different compounds can be used such as the RTV above, Fujik paste, JB Weld, or some other such as polyurethane. It’s also possible to grease the driver as well so that the potting solid becomes a fitted mold. The properties you want to achieve will help dictate the best method.
The drivers I’m looking at are probably QLITE and MTN-17DDm in Convoy hosts (M1, M2, and C8).
What grease do you use on the driver?
Depends on the potting compound. You want something the potting won’t bond to or mix with. Also, it can’t vaporize with heat or it will pooch the reflector. I suppose if removability is important one could use whatever grease accomplished the first and after the potting cured remove it and clean off the grease to prevent gassing. Maybe just use thermal grease under JB.
Silicon oil works great for the potting I’ve done.
What potting compound do you use over silicon oil?
I use a mix of rtv and silicon carbide powder 400grit I got from eBay. I think it’s a greaf combo. It’s not too messy. I mix it in a glas dish and it wipes right up with some isopropyl alcohol. If I pot a driver and brush a bit of the silicone oil in the pill, I can slide it back out if there are problems. I never like cutting into it to reflash or problem solve but it’s not hard to re-expose the components with this method.
I’ve also used liquid electrical tape and different combinations of the two but the electrical tape kind of messes up the consistency of the material. It doesn’t mix well. Using the electrical tape alone works though it’s much harder to re-expose the components if. DeDee.