I'm hunting for transparent heathshrink to insulate my FrSky R-XSR receiver which sits between the ESC and FC boards. Want it clear to see the LEDs but all I have is black or red. The little board is approx 11mm in width.
Is the size of heatshrink measured as circumference or diameter? 
How do you heat that enough to shrink but without cooking the underlying electronics?
Are there other components on which clear insulation would be beneficial? Maybe the VTX?
Thanks

The key is to do it quickly. I refuse to use hot air guns. A cigarette lighter is better. Stay away from rigid and thin heatshrink (the stuff that comes with products). It’s crap. Assume approx 160 - 180 percent of the size of where you want it to be before you shrink. Always cut out a bit of heatshrink that covers a bind button, you don’t want that covered. Do that after you have shrunk it as it’s close to impossible to track position and size of the cutout before shrinking.

Ok, so you don't see the need for CLEAR stuff? What about seeing the LEDs?

Also I'm confused as the the meaning of the material's measurement.

If the board is approx 11mm wide should I get 15mm (if they brand it with the diameter) or 30mm (if they sell it measuring the circumference)?

Thanks a lot

Why not make your prized quad look like a pot of desert.

Use clear heatshrink definitely. Just not the stuff that comes with things like crossfire receivers etc. buy the clear heatshrink from an electronics store, it will be thicker.

Sorry to clarify the size, heatshrink before shrinking should be approx that percentage larger then the end size you want it to be. Ie: if a rx circuit board measures 11mm in width then get 20mm sized heatshrink max. So your 15mm stuff would be fine.

It can be a bit trial and error.

Just get a selection of different diameter heat shrink sleeving then there will be more chance of you having something that fits, and you will always find a use for the other sizes eventually. It's like screws. You can never have a big enough selection on hand to pick from.

Did that already but they only are opaque red and black. Now ordered a few different sizes of clear shrink from Ali ... Thank you

Hi rjalex,

Heat shrink tubing is measured by diameter, generally in mm, and normally shrinks at a 2 to 1 ratio. 20mm will shrink to about 10mm. For my FrSky receivers, I have found that 15mm works great; you don't have to shrink it all the way, just enough to be secure around the board.  As a size reference 3/4 inch is a little over 19mm. Also, some tubing does shrink at 3:1 ratio.

I don't heat shrink the VTX because these get hot; some very hot. You want that thing to have cooling which the heat shrink prevents. I am not sure of the heat tolerance for heat shrink, but I would be concerned that the heat from the VTX could actually melt onto the circuit board {now that would likely be a mess}.  I also keep the heat gun moving so as to not overheat the circuit board. 

I bought a variety box of clear Conshine 2:1 Heat shrink tubing on AMAZON  and  some clear 20mm Heat Shrink from FPV Cycle.

Another thing, most of the clear heat shrink does NOT have glue inside (good for circuit boards), but the black and red heat shrink come both with glue and without glue. I often buy the "glue inside" because I think it helps where you have wire joints. For me, every little bit helps. On the other hand, I would NOT use glue on a circuit board because you might have to cut it off later or make a hole for the button. 

Very interesting read!!! Hadn't thought of the VTX being a small stove
Just today as I was reassembling the Tyro99 (and chopping off the third SMT capacitor from the ESC board) and debugging my telemetry, which I need to do under power, the VTX is really really hot and almost thought of buying a little fan to cool it a tad when I work on the bench.

I also find very interesting your "glue inside" idea and agree, every little thing helps avoinding loose wires.

Thank you and have a great weekend.

(31-Oct-2020, 11:37 AM)ph2t Wrote: Sorry to clarify the size, heatshrink before shrinking should be approx that percentage larger then the end size you want it to be. Ie: if a rx circuit board measures 11mm in width then get 20mm sized heatshrink max. So your 15mm stuff would be fine.

Thanks a lot.

(31-Oct-2020, 06:14 PM)rjalex Wrote: Very interesting read!!! Hadn't thought of the VTX being a small stove
Just today as I was reassembling the Tyro99 (and chopping off the third SMT capacitor from the ESC board) and debugging my telemetry, which I need to do under power, the VTX is really really hot and almost thought of buying a little fan to cool it a tad when I work on the bench.

I also find very interesting your "glue inside" idea and agree, every little thing helps avoinding loose wires.

Thank you and have a great weekend.

I actually have a smal usb powered fan for this purpose! Keeps dji air units, vistas, and vtx's cool. Also pulls solder, conformal vapors away.

Hi PrisonerZero,

Good idea, USB powered fan. I will look into getting one.     Thanks  

If you order from Hobbyking,China EBay sellers,you can get 20-100 times the quantity for the same or fraction of the price.

Heat shrink usually will say it’s size,thickness and shrink ratio.
Here is a link to a bunch.
https://hobbyking.com/en_us/catalogsearc...t%20shrink


Measure width of receiver or components to be covered and the diameter of heat shrink must be bigger.
For a receiver that’s 10mm wide you’ll need 12-15mm heat shrink.

I just wanted to add my two cents. I usually get rolls of shrink tubing through ebay. When you are selecting tubing, there are two common type. PVC, which is the thin stuff that comes with most electronics that ph2t mentioned. When shrunk down, it is kind of hard and not pliable. Then there is polyolefin. This is what most of the insulation tubing you use on wires. But they do come in clear and of all sizes. It is thicker and very pliable after shrinkage.

Generally speaking, the size is given as the measurement of the inner diameter (ID). Occasionally you will see the measurements as the flat width (half circumstance).