Cheap Dew Prevention and How to Make DIY Dew Heaters for Astrophotography

[@EvenTheDogAgrees]

The sort of wire you used near the end is sold on Amazon or AliExpress as well. And better quality than the one you got; I had no trouble with mine breaking as I was manipulating it. It's used for things like heated car seats. You can get it in different resistance ratings (ohm/m), so you can select the one that's the best fit for your desired wattage and length.

[@Cheapass-tro]

That's good to know, thanks. Can you say what it's called please? I looked up "heating wire" and only Nichrome showed up.

[@EvenTheDogAgrees]

@@Cheapass-tro Seems KZbin ate my original comment. Nichrome is indeed what you want, but insulated. Comes in a wide variety of resistance ratings. I search "heating wire" and find some results, although not as many as I used to. I'm sending you an email with some listings, since KZbin auto-deletes comments with URLs in them.

[@notmyname327]

I loved the graphics in this one! Really clear explanation, thanks!

[@Cheapass-tro]

Thankyou for watching, noticing and saying!

[@lppiren6398]

Thanks!

[@Cheapass-tro]

and thank you!

[@jonperry7507]

This is a really handy how-to to keep around. Thanks!

[@Cheapass-tro]

That's what I was aiming for. None of my videos are the viral kind, just reference. Thanks!

[@davidd6130]

Thank you this is execllent stuff.

[@Cheapass-tro]

Your comment is much appreciated!

[@derrymurphy3944]

Excellent vid mate use this equation when I was vaping and making my own coils for a tank

[@Cheapass-tro]

Thanks Derry.

[@jasonpatterson8091]

Great video! In the US we call it "rozzin." The first syllable rhymes with the beginning of nozzle and then the word "in" at the end. Not sure if UK pronunciation matches for this one.

[@Cheapass-tro]

Thanks! I'll adopt that until someone over here says otherwise.

[@dougcox835]

It's rosin. Here's what Wikipedia says: Rosin (/ˈrɒzɪn/), also called colophony or Greek pitch (Latin: pix graeca), is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperature. It chiefly consists of various resin acids, especially abietic acid.[1] The term colophony comes from colophonia resina, Latin for "resin from Colophon" (Ancient Greek: Κολοφωνία ῥητίνη, romanized: Kolophōnía rhētínē),[2][3] an ancient Ionic city.[4] It is an FDA approved food additive.[5]

[@buildingblocks9320]

I've enjoyed watching your caravan conversion videos today...But it would be best if you considered buying a multimeter. It will help a lot with your DIY due straps.

[@Cheapass-tro]

Thanks. I do have a multimeter.

[@iamjessieray]

Very nice video. I had thought about it before, but for some reason I just never realized exactly how simple these things are. I plan to build myself a 12 power source so I can just run one extension cable from my house and plug it in to my scope (which stays set up under a cover) so that I don't have to keep fighting with all of the stupid AC adapters and trying to find ways to plug them into a power strip. Once I do that I will get on making some dew heaters and will probably make a buttload of them since I have several telescopes and even end up with dew issues on my binoculars. Maybe I could make some dew heaters for those that I could run from a USB power bank in my pocket... You're going to get me in trouble with my wife for having parts and projects everywhere!

[@Cheapass-tro]

Hey don't throw me under the bus! Ha ha! Good luck with the whole power thing.

[@dumpydalekobservatory]

Very well explained Nugsy & a nice job to, I could do with something for my secondary as I have no room for the DIY foam dewshield I have for it so I may delve a little further cheers.

[@Cheapass-tro]

If you have the bits you can knock one up in 15. Otherwise there's this : www.ebay.co.uk/itm/145886922398

[@dumpydalekobservatory]

Thanks mate I might message him to see how big it is as I bought one when at Kelling & that was to big cheers

[@stay_at_home_astronaut]

Good video

[@Cheapass-tro]

Thanks!

[@alexandrevaliquette3883]

Your intro make me laugh! Thank you!

[@aripaule]

great tutorial, really appreciated! Do you think it is possible to do it with 1/4 watt resistors, for occasional use?

[@Cheapass-tro]

In my head it should be okay. I doubt you'd find any limits doing these. Seemed a bit strange to me that ½ watt resistors were recommened, but a few sources did. I'd give it a shot but I wouldn't recommend it to others.

[@OldCurmudgeon3DP]

Plumber's solder is sometimes acid core. Not compatible w/ wiring. 😅

[@dougcox835]

I've noticed that they don't even use acid core in plumbers solder anymore. You would need to have very old solder for that.

[@mikehardy8247]

I have solder from the 1960's.

[@dougcox835]

I think my issue with this is that far too often you see warnings and cautions about edge case issues when common sense should apply. In this case I don't think it would really matter anyway. It's just a string of resistors. It won't last for years and years anyway. One of the resistors will break long before the acid manages to etch through the wire.

[@terryrsh8927]

I've had good luck with nichrome wire from amazon

[@Cheapass-tro]

Many have. I just chose resistors as it's an easier choice in my mind.

[@mikehardy8247]

Exactly what brand commercial dew heater do yo show? I like the plug being directly on the dew band. Some that have a cord hanging off, expose wires, resulting in a spot where wires can break.

[@Cheapass-tro]

www.amazon.co.uk/gp/product/B09N95JX32/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 The wire on mine DID break at the switch and I re-soldered it. A spot of hot glue may work as a preventative measure?

[@mikehardy8247]

This one doesn't have a plug fixed to the material, so it can pull loose easily. Oh well. Thanks. I found 20 feet of #22 nichrom wire insulated with heat shrink draws 6 watts at 12 Volts. I wrap mine around the typical green lasers for aiming. Their output diminishes drastically below 50 degrees F.

[@jesuschrist2284]

I use your guide scope heater on my imaging scope. Never seems to get very warm even on high :(

[@Cheapass-tro]

Neither does mine but it only needs to keep the tube slightly above ambient. Your hand is warm enough to prevent dew on the scope so it may not feel warm enough to your hand. Only worry if it doesn't resist dew. Then up the wattage (lower the resistance), which you may want to do anyway for the winter.

[@Cheapass-tro]

It just occured to me that you may be talking about the purchased one? If so, see previous answer. Again, no need to worry. You can't increase the wattage on this though.

[@jesuschrist2284]

@@Cheapass-tro yeah sorry. I did mean the one you bought. Not had a dew problem though so it must be warm enough? :)

[@Cheapass-tro]

@@jesuschrist2284 Should be warm enough for the winter. Mine is, but still - it ain't very warm. Doesn't need to be.

[@Cheapass-tro]

Hey JC I just remembered something. Mine needs a 5v 2a power source. Many 5v USB ports only offer 1 amp. If the dewstrap's switch lights up though, it's working.

[@Bukuzoid]

Paint it white (both the tube and dew shield outside) - it solve most dew problems. Radiative cooling is much more affecting dark and black surfaces then white, so your dark tube and it's black parts when under clear sky literally trying to equalize the temperature with the space. Paint it white and due to lack of radiative cooling it will stay at air temperature and will only be covered with a dew when there is a fog everywhere outside. I never use heaters because it's bad idea to deliberately add heat streams into the tube, distortions like that are clearly visible with focault test on star or defocused bright star image. Thanks and good luck with clear sky!

[@Cheapass-tro]

Interesting. I'm looking at restoring my old Newt' at some point and was planning a vinyl wrap for it. So you're saying I should use a white wrap and the dew shield should be white outside?

[@dougcox835]

The heat applied should be only enough to keep the hardware above the dewpoint. If done properly it shouldn't be enough energy to cause air currents. White paint only puts off the inevitable cooling. Can't hurt though. Maybe even wrap some foam around the tube while you're at it.

[@AmatureAstronomer]

Inventive.