Home Forums Hunting & Shooting Ask The Gunwriters How hot can scopes get ....

.... without damaging the seals or other components, that might make them stop working right? I know some are tested in hot water, but I can't remember if the temp is 140, 180 or 212.

The reasons I ask are here on the coastal plain of SE GA., leaving a gun in a locked car in the baking summer sun can get temps inside the car to over 150 degrees pretty rapidly. It seems the humidity we're famous for (infamous?) works as a reverse heat sink, and imparts additional BTU's or whatever to the metal or other materials, and can make the temps in a vehicle rise very rapidly and to temps that are concerning to me.

I've also wondered if scopes can be Cera Coated. The baking on process would, I'd think, be too much for an already assembled scope, and I'm guessing the seals probably won't take kindly to the higher temps? Not sure what the seals are for the various makes, but do they vary from mfg. to mfg.?

Just wondering what temps would be safe for an already assembled scope. In mfg., I know they can do things to the tubes that probably can't be done after assembly, right? Any info you can provide would be appreciated.

I'm guessing if I want to color a scope, I'm pretty well stuck with spray on paints?

I've seen many CeraKoted scopes.

I seem to recall a version of Cerakote that didn't need baking.....like a DIY version perhaps ? I know I wouldn't be baking a scope w/o having it re-purged.

There are two kinds of cerakote, thermal cure and air cure. The thermal cure is the tougher of the two and is baked on. Air cure does not need heat to cure, and that is the type used for optics. I apply lots of cerakote and have both types.

...so I wasn't imagining that. Good to know.

I am not sure of the exact temperature before damage is done, but I do know if they fog up and you put them in your oven at 250 degrees it will blow the ocular off at high enough velocity to brake the glass on the oven door.

TFF Where did you come up with that silly stuff? SM wannabe?

Holy schitt that was funny..........that's material for JB's next optics book right there.

this is really some serious chitt, and not at all funny down here in the south due to the high thermal heat index from 100% humidification. We had a woman melt her CCW a Glock 19 by leaving it in her car in a parking lot at the IP Resort in Biloxi MS while she was on a 3 day drinking and gambling binge. She found a pile of black plastic along with 13 9mm cartridges imbedded in the pool of goo. Ask Bluedreax he saw the whole thing.

I would not worry about it....If the interior of a vehicle can take it..So can the scope. I have a pair of Pentax Binos that have been in my truck for Two years.

Yep, it gets so cold around here in the winter that I can put a pot of boiling water outside and it freezes so fast that the ice is still steaming.

I won't comment on melty Glocks. However, I have wondered about a similar question as the OP.

Many years ago my Dad bought a Leupold scope at a garage sale. He got it for near nothing, because when you looked through it, everything appeared to be underwater - blurry, waves, funny colors. I gave him the $5 he had in it, and sent it to Leupold with a note asking them if they could give me a quote on fixing it.

My first experience with their customer service happened a few weeks later when a brand new scope appeared on my porch with a "no charge" invoice. I have been one of the faithful ever since and have bought a LOT of their scopes.

Anyway, dad was pissed because he didn't know about their warranty either. That made it even better, still have the replacement scope.

But to the point - Dad claimed that he had seen similar damage before on scopes that were on rifles hung in pickup back window gun racks. (Common in those days). He claimed that in certain circumstances the hot cab and the hot eastern Montana sun shining through the scope like a magnifying glass would "cook" the inside of the scope, something would let go, and the scope would fail.

Always wondered about that.

I'm gonna have to call BS on that story! One of my Glocks has lived in my truck for the last 20 years in the Texas heat with no effect what so ever. And it certainly has not melted.

I know all about this stuff, it got so hot in the desert where I used to live the 'taters I dug up was already baked! ANd them New Mexico peppers, already roasted too!

Seriously though, it can get really hot in some places. I lived near Hoover Dam and the black dock bumper on my truck picked up so much heat in the SW facing carport that the tail light lenses distorted. One could not pick up tools one left out in the sun without gloves. Of course, we saw a number of days over 120F there.

I would hope a scope could handle it, our guys overseas probably hope so too.

Geno

I bought the scope from the man who blew it up. I have known him for years and is a stand up guy. Still wondering, I asked his wife the next time I came over for dinner. The first mention of it, got her fighting mad and she assured me the incident was true and hubby had not yet been forgiven. I bought it for $5 as he cross treaded the ocular back on the tube as the treads were messed up. So being a true mechanic that he was he used blue goo on the treads. I sent it back to Weaver (it was a 3 to 9) and they sent me a new one for $49 IIRC.

I remember when a dealer in the St. Louis area had a fairly major fire. They had a glass optics case with binoculars and scopes and such.
I saw Swarovski binoculars that had been turned into a puddle of green goo. All of the rubber 'armor' on the Leica's was melted off of the barrels of the binoculars.
The rifle scopes were still sealed but the lenses on either end had been ruined by the chemical reaction from the combination of the smoke and the fire department's use of water and other chemical fire supression stuff. The scopes were ruined and their finish was destroyed but the had held their integrity and the internal glass was fine.
I have no idea how hot it got inside the building but I'll never forget the devastation that it brought to the gun department.

Around here it gets so cold in winter that it is impossible to boil water with a normal stove.

It was so cold around here a couple of years ago that we took turns sitting in the refrigerator to warm up.

^^^^^^ This I leave my steel IOR 7x35 binos on the front seat all the time and on sunny days it gets hot enuff in the sun for the latch on my seat belt to leave a mark. probably 165 or 170 degrees. Hottest I ever seen a car get was a Black on Black 911 we had at our dealership. No tint just regular old style glass. It had an thermometer in the ac duct and it read 178 sitting in the sun. If anything is covered it will be much cooler then direct sun.

Left Leupold scopes, binoculars and several other brands of bino's in hot locked rigs in 100 plus degree summer heat many times. I have an electronic thermometer that quits at about 150. Have seen it not reading plenty of times, never hurt any of the optics.