secret compartment box?

I really love what this person did I was wondering does anyone have any simpler projects? I wanted to make a box to fill with gifts with a hidden drawer/compartment where I could put a scrapbook. Its a gift for my boyfriend and where this box is very nice I dont think I would be able to accomplish something like that being a newbie to work working.?

Question by    |  last reply

Why doesn't Instructables have a hidden compartments contest? Answered

Instructables shows people how to do everything; except make secret compartments.  They should have a contest for it to see which one is the best, and blah blah blah, they get prizes, blah blah blah, you should all know the drill for contests by now. Afternote: Hey thanks guys!! Hopefully soon there will be a hidden compartments contest.  Can't wait to see the results!

Question by whiskrs   |  last reply

brass knuckles hidden blade?

Hi! I'm trying to make brass knuckles with a blade hidden inside it's for a cosplay. The idea is to have brass knuckles and at one point in the action of a button and out a knife inside the brass knuckles in a small compartment inside the fist. For reference I have the OTF Assassins Creed hidden blade. But on a small scale and with a button instead of rope. As you would do ?? Thank you very much!

Question by marcoantonio.saldonguerrero 

(newsletter) Hidden Compartment, Watermelon Keg, Ferret Wheelchair...

Sign-up for this newsletter: Welcome back! NEW CONTEST: Converse Back to School in Style Contest - Make or customize anything school-related and win a gift card so you can make your own Converse shoes!SINGER Kids Crafts Contest - Create something crafty with or for a kid and win a sweet new serger or sewing machine from SINGER!Forbes Teach Me Fast Contest - Make a 30-second how-to video and win an awesome Flip MinoHD video camera! Winning videos will be featured on Glue Cardboard Contest - Build anything using cardboard, and win a huge package of Gorilla Glue supplies and gear!Ends August 23: Low & Slow BBQ Contest - Cook up something tasty and win a Weber Smokey Mountain Cooker, and autographed copies of the new Low & Slow BBQ book! Bike Dog Walker The Wild Pig Smoker Make a Magnetic Fish Tank Cleaner Hidden Cabinet Behind Fake DVDs Make or customize anything school-related! FerretMobile: DIY Ferret Wheelchair Make a Resistor Reference Card Listen to Shortwave on an AM Radio Home Made Tonic Water Concentrate Share something cool quickly! Get crafty! Make a Sekkaboku Rubbing Crayon CIR Sand Casting System Air Pumped Patio Fireplace Homebrew Cold Smoke Generator Submit a cardboard creation and win a prize pack from Gorilla Glue! Cook up something tasty today! Ends August 23 Pulled Pork on a Weber Kettle Grill Smart Power Strip for Your PC Stone Tile Lamp Make a Watermelon Keg Sign-up for this newsletter:

Topic by fungus amungus 

How could I make a hidden space in my room? Answered

I have a fairly small room and i want to make a hidden space big enough for a small person to fit in. Could i build a piece of furniture and a compartment in the back? What about making fake drawers under the bed? Are these awful ideas? Do you have any more? p.s. I don't have a closet.

Question by Herbal_T   |  last reply

suggestion topic

So I recently entered the hidden doors/compartments contest (my first), and was thinking that it would be nice to know if people are voting for me... just suggesting the addition of a vote counter (unless it exists and I missed it), not necessarily to see other peoples popularity, but just to see how you yourself are doing.

Topic by rajacasa   |  last reply

Suggestion: Contest Vote Counter

So I recently entered the hidden doors/compartments contest (my first), and was thinking that it would be nice to know if people are voting for me... just suggesting the addition of a vote counter (unless it exists and I missed it), not necessarily to see other peoples popularity, but just to see how you yourself are doing.

Topic by LordBenjamin   |  last reply

Help with AutoCadd Drawing

I’m working on a project for my dad for his 70th birthday that consists of building a puzzle box. The box takes 6 separate moves to open the compartment. I had a company laser cut all the pieces as everything has to fit together like Lego. There is one key to the box and 40 keyholes on the outside, 95 hidden keyholes for a total of 135. Problem is, when the pieces were laser cut, the keyholes ended up being too small. I need to adjust the keyholes and I don’t have access to a CADD program ( I had my dad draft up the original document without him knowing what if was going to be used for). If anyone can help with this it would be greatly appreciated. I will probably make an Instructable of the box once it is complete, after my Dad has figured it out. Cheers.

Topic by 69valentine 

Any ideas for a bedroom?

I am a 16 year old who loves math,science,and electronics(and programming).I have to design my new room(a 14'x20' empty space right now) and am out of ideas.I tried searching the site for some cool ideas,but my searching skills are pretty bad and all I could find was some secret hidden compartments(which is more than cool btw),and a study table.My woodworking skills are not very good,but I can get almost anything done with a little help from my awesome neighbour,and I think my knowledge in electronics is decent enough for some basic home automation.Do you have any cool ideas i could work on?Any help would be really appreciated :D tl;dr  designing room,need ideas thanks

Question by utkarshsinghal   |  last reply

secret boxes for the outdoors - revisted

Hello, Instructibles gang…. I posted several questions related to “secret boxes” over the weekend. I got some feedback suggesting that the inquiries should have been combined, and that they didn’t include enough information to lead to worthwhile answers. The topics came to mind sort of haphazardly, so I do apologize for the scattershot nature of the original posts.  As to the latter issue, “secrecy” was never the intention… rather, it was that this is all still in the “doodle” stage of planning, and I didn’t have a lot of details to give in the first place. Nonetheless, I’ll try to get a little more concrete - and combine the three questions in the process. I’m a letterboxer. Letterboxing stuff comes up now and then on Instructibles, but for those who are unfamiliar, it’s similar to geocaching (which seems to be more well-known), but with an added, artistic component. Whenever I see “secret boxes” in my regular Instructibles emails I think about whether the designs could be adapted for letterboxing purposes – either “on the trail” or at limited-time events and get-togethers. Naturally, I’ve been looking through my bookmarks and doing Instructibles searches, google searches, etc., but I’d appreciate if anybody might be willing to point me toward some of their favorite designs. I’m increasingly interested in creating boxes that are “hidden in plain sight” – not concealed, but rather “hidden” by virtue of the fact that they look like something else – such as a birdhouse or mailbox – and might in fact actually BE that something else, in addition to being a hiding place. I would welcome any suggestions that the community thinks might fit the bill. Here are some of the preliminary ideas I’ve been thinking about: 1)      Folks hunting the box are told to take a 9v battery, with the snap-on wire leads, with them. When they get to the box they have to put the leads into two holes, where they and the battery complete a circuit. The current trips some sort of latch, allowing a door to be opened. Of course, the door would have to re-latch when closed again. 2)      Something similar to #1 but a little more electronic. Hunters might be given a schematic of a simple Thing that they have to build and take with them. This would, essentially, be a key. I’ve already received an interesting suggestion involving RFID chips. I also got to thinking that a USB connection could be very discreet and easily hidden, and THAT got me thinking that the “key” could perhaps be something on a smartphone… data rather than hardware. I’ve got basically no background in electronics, but I’m fairly good at following directions…. 3)      Pretty much any other contraption where some sort of hidden compartment would be created, which can be accessed through some sort of process that likely wouldn’t happen randomly or accidentally. (I know… could I be any more vague?) The boxes would likely be mounted to something solid - a tree, wall, post, etc. - but I imagine it could be that you take it down, do what you’ve gotta do, and then put it back. And they would most likely be exposed to the elements and would have to stand up to being out of doors. The size of the compartment is entirely flexible…no minimum or maximum dimensions.  And, as stated, I’m a beginner when it comes to electronics – but I am more than willing to learn! I know what I’m trying to describe, but please let me know if I’m not doing well in communicating it to others. Like I said, I’m not trying to be secretive. It’s just that it’s still a very open-ended scheme – not many specifics – and I’m interested in hearing how different folks might approach it. Please shout if you have any thoughts or want more info.

Topic by Purple Chez   |  last reply

(newsletter) DIY Plasma Cutter, Power a Car with Trash, Steampunk Monopoly

Jan 8, 2009 Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup1","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); } Welcome back! Help us make 2009 a Green Year! Show off a clever reuse for a plastic bottle in the Tap'dNY Keep the Bottle Contest and win a Voltaic solar-charging backpack! The Craftsman Workshop of the Future Contest has closed for entries. Help choose who wins $25,000 in Sears gift cards by voting now! The Homemade Holidays: Holiday Gifts Contest has closed for entries! Help choose the winners by voting now! The Homemade Holidays: Holiday Decorations Contest winners have been announced! See who won! Convert your Honda to Run on Trash by jimmason Cheap iPhone Macro Lens by ch0rtle Giant Atari Joystick Lamp by seamster 48V Electric Bike by Radioactive_Legos Vote now! Win a Voltaic solar-charging backpack! Inlaid Wood Box with Hidden Compartment by technoplastique Strap a Leaf Blower Engine to a Bike and Go Fast by Jnkyrdguy Hacked Calculator Prank by Kipkay Build A Mobile Bar - BaR2D2 by jamiep Make a Fractal Antenna for HDTV by williamruckman Build a Honey Extractor by doozer_not_fraggle Build a Peg Board Tool Cart by sensoryhouse Electrified Monopoly Steampunk Style by antibromide Homemade Holidays Contests Vote for your favorites! See who won! Homemade Plasma Cutter by jandgse812 Snail Art Car The Golden Mean by jonsarriugarte Custom Star Bike Wheel by MasterRed Make a plastic gadget a little more beautiful by radiorental Now go make something awesome, and I'll see you next week! - Eric Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup2","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); }

Topic by fungus amungus   |  last reply

Solar Death Ray, Robot Foosball, Snow Cannon...

Sign-up for our newsletter here. Dec. 27, 2007 Welcome back! The Laser Cutter Contest ends on Jan. 1, 2008. If you're still sitting on an amazing Instructable, submit it now to win a VersaLaser worth over $15,000! Don't forget to enter the Homemade Holidays Contest! Share your homemade holiday gift ideas through an Instructable, a Slideshow, or a Video, and win great prizes from CRAFT magazine! Check out these cool instructables! Giant Fresnel Lens Deathray: An Experiment in Optics So you don't have access to your own rail gun or military space laser....but never fear, we'll use the sunlight in your yard to instantly set things on fire! posted by DrSimons on Dec 26, 2007 Build a Microwave Transformer Homemade Welder Making a DIY welder is easy to do and it's pretty much FREE! If you feel comfortable playing with electricity, check this out.posted by stasterisk on Dec 24, 2007 Fix a stuck pixel on an LCD monitor Fix those pesky stuck pixels in just a couple of minutes and enjoy a fully functional monitor. posted by Line Master Jorbob on Dec 23, 2007 The Ambience Enhancer Listen to your music in style with this wondrous steampunk device.posted by Porkshanks on Dec 21, 2007 How To: Jailbreak your Ipod Touch 1.1.1 to 1.1.2 (Windows) Jailbreak your iPod Touch to add some custom applications. This is worth it for the instant messenger alone. posted by RTheaven on Nov 19, 2007 Just a few days left to win a $15,000 VersaLaser! The Stirling Engine, absorb energy from candles, coffee, and more! A simple way to get introduced to the Stirling engine. Unleash the power!posted by thecheatscalc on Dec 21, 2007 Build a Wind Harp!A wind harp is just what the name says, a harp played by the wind. You don't need lessons with this instrument, just a light wind will do.posted by botronics on Dec 26, 2007 Cheap secret compartment! Learn how to make a secret compartment that can be built into a bookcase, or some other piece of furniture. A sneaky lock keeps it hidden. posted by Hoverboy06 on Dec 21, 2007 Autonomous Foosball Table The robots are take over living rooms one foosball table at a time. Are you with them or against them?posted by eski on Dec 25, 2007 Pneumatic Snowball Cannon A lot of people make potato guns, but it's winter so let's shoot some snowballs instead! posted by cvxdes on Dec 18, 2007   Now go make something awesome, and I'll see you next week! - Eric

Topic by fungus amungus 

Switch To Battery Power When Mains Power Is Lost ?

Go-to-War Gear--such catchy hypothetical stuff writes well, but it can turn real all too fast. I have acquaintances in Houston who had less than an hour to leave their homes before the floodwaters overtook them. They had just enough time to throw their important papers into the dishwasher (a handy dry spot for important stuff in a flood), grab their kids, and head for high ground. The recent CaliforniaThe Hunting Shack offers both .45 Colt and .45 Schofield loads (left). Ramshorn gripped STI Texican and Texas Longhorn Arms No. 5 were used for testing both the .45 Colt and the shorter .45 Schofield ammunition. wildfires typically covered 100 meters in 3 seconds. Do you really have what you need to grab and go? Even in America, you can go from full stop to life-threatening crisis in moments.A Proper Foundation: You can measure a man by his boots. I burned through several sets during my time in uniform. My favorite pair of combat boots is more comfortable than house slippers. Combat-proven features make them rugged. Speed laces keep them fast.I wear boots every time I fly. The speed laces let me get into and out of them easily for the obligatory TSA assessment. Keeping the best insoles for standing all day maintained and the drainage vents clear ensure they're comfortable.Air travel is not as much fun as it was once, but an airplane cabin is comfortable enough. Now imagine that same space upside down, dark, and populated with jagged metal, screaming hysterical passengers, fire, and worse. Never remove your footwear in an airplane.Whether the threat is a wildfire, hurricane, tornado, or civil unrest, you will always need proper footwear. Keep your favorite pair of broken-in boots right next to your bugout bag. Think it through and have something similar for each member of your family. Anything built on a faulty foundation can ultimately fail. If you have to move in a hurry that foundation is a good pair of boots.A Proper Bag: A Bugout Bag is pretty stupid without a decent bag. I have a nice utility pack I picked up at our local Walmart for next to nothing. It is lightweight and serviceable enough. However, mygo-to-warbag is a Brazos concealed carry pack from Flying Circle Gear. It's the best I've ever seen.For starters, everything about the Brazos bag is just a little bit heavier than everybody else's. The stitching is more rugged, the material is more substantial, and the zippers are of the big beefy sort. Additionally, the bag is exceptionally well imagined.There are two spacious center compartments large enough to manage a laptop. A small top pocket packs your wallet and incidentals and includes a hidden ID card holder. There is an integral hydration pouch along with four zippered pouches on the sides and a larger version on the front.The outside of the bag is festooned with MOLLE webbing. Thread a pair of ammo pouches in place for your shades or spare reading glasses. They can even carry ammo in a pinch. I can and have lived out of mine for extended periods while travelling, camping, or hiking.The handiest feature on my Brazos bag is the hidden "pass-through" pocket on the back. This discreet compartment is zipper-accessible from either side and is the perfect size to manage a decent gun. Open both sides and you can slide the pack over the handle of a rolling suitcase. Drop in a soft body armor panel and wear the pack backwards and you have an improvised tactical vest.

Question by kingandsoraka   |  last reply

The Dream Factory - Squid Labs and Instructables in Wired September 2005

This was Instructables' big debut. The author, Clive Thompson, came and hung out at Squid Labs for a couple of days, and later on we had a hilarious half-day photoshoot where the photographers couldn't remember Dan's name and had to keep calling him "wrench."Wired 13.09 The Dream Factoryby Clive ThompsonThey're already living that future in a small warehouse in Emeryville, California. It's the headquarters of Squid Labs, run by a gang of five MIT alums who by day create prototypes of new technologies for outside firms - and by night fabricate weird gizmos just for fun."Everything I own is basically one of a kind," says a cheery Saul Griffith, one of the cofounders, as he crouches on the floor of his dust-covered workshop, rooting through an enormous bucket of metal brackets and bolts. A tall, shaggy Australian, he's wearing ragged flip-flops and a pair of cargo pants so stained with oil and grime that I can't determine their original color. Dozens of his group's inventions lie scattered about: a Frisbee embedded with microchip-driven LEDs, a set of robots precision-cut from plastic, a bunch of helmet-mounted laser-and-GPS sensors designed to help firefighters locate one another in a blazing house.Today, Griffith is building a "hybrid electric bicycle" with a hidden battery compartment inside the bike's 4-foot-long, chopper-style front forks. To hold the forks in place, he spent the morning designing a bracket, then cut out a flat template for it on Squid Labs' laser cutter. Now, with that template as a guide, he hacks the shape out of quarter-inch steel, using a terrifyingly loud metal cutter. "I'm really into this 'tractor' aesthetic, getting everything to look like industrial machinery!" he hollers over the cutter's shrieks, while a 3-foot cone of orange sparks flies up and ricochets off his face.Every few minutes, Griffith pauses to snap a photo of his progress. When done, he'll write up a comprehensive guide on how to build his project. This, he argues, is the next crucial step in fab culture: getting hobbyists to carefully document their plans and share them online. Squid Labs is hoping to kick-start such sharing this fall when it launches - an open database of interesting projects and fab techniques, "kind of like a Wikipedia for making stuff," Griffith explains. If people want to build his electric hybrid chopper bicycle, they'll be able to download the CorelDraw design of the bracket and send it someplace like eMachineShop to have their own copy printed."We got inspired when we looked at all these guys who'd engineered these incredible, modded parts for their Harleys. They'd have amazing photos of them, but they'd never post the CAD image," Griffith says. "We were like, Why not go open source?"Later that day, I get a taste of how weirdly transformative this idea is. I'm hanging out with Dan Goldwater - another Squid Labs cofounder - and admiring one of his inventions. It's a pair of plastic gears that sit on a bike pedal and power a tiny generator. As you ride, you can run LED lights or a radio. I tell him I'd love to have a version of it myself. So a couple of Squid Labs guys go over to the laser cutter, pull up the design, and a few minutes later hand me exact copies of Goldwater's gears. Design once, print often. "Pretty cool, eh?" Goldwater grins."Griffith imagines that fab tools could produce new economic models for creators. Suppose a hobbyist made a cool plastic exterior for an MP3 player. Suppose she put the design online, and 700 people downloaded the file and had it printed at eMachineShop. "At what point," he asks, "would a manufacturer say, Hey, there's a market here - and offer to buy the design from her?""So, sure, soon we'll be able to build anything. But should we? "Let's say everyone suddenly can make their own hood ornaments. What if they actually do that? The real world would look like the Internet in 1996, when people started making their own Web sites." Griffith shudders. "Remember those hideous-looking psychedelic backgrounds and stupid animations? And blinking tags?""Rainbow dividers," Goldwater adds.It's a good point - and it makes me anxious about my guitar. Sure, it looked fine onscreen. But what if it turns out to be a monstrosity in my hands? Recalling my decision to use clear acrylic for the body, I break into a nervous sweat. It's going to look like something from a mid-'80s, big-hair heavy-metal band! What the hell was I thinking?Griffith interrupts my panic to announce that his chopper is ready. He wheels it onto the street, all five Squid Labbers in tow. Eric Wilhelm, a lanky designer, offers to be the test pilot. He straps on a helmet and mounts the seat. "Does it have brakes?" he asks."Sort of," Griffith says."It's amazing how often brakes are an afterthought," Wilhelm sighs. Then he hits the electric starter and peels off.

Topic by ewilhelm 

Options to improve cooling and reduce consumption for portable coolers

I recently had to start learning how to service airconditioners on the fast and that learning got me thinking about my portable coolers.... Some of us like to go camping or on longer fishing trips, so there might be one of those 3-way fridges in use or a better cmpressor model. The one thing they all have in common is that they can only cool down to a difference in ambient temperatures. No matter which way we turn it the cooling produces heat and that needs to get away somehow. The other big thing is the cooling cycling - or the lack of it on a warm day. After some reading and thinking I came up with some ideas that might be applicable to your existing cooler if you are willing to mess around a bit. Let's start with the produced heat, shall we? Down here in Australia most people either have the fridge in their4WD or camper. In a car or small camper trailer there is often the problem of airflow, so the cooler might be doing overtime for no other reason than a lack of airflow. If you check online sites like Amozon and Ebay you quickly find fan systems meant to be installed inside the cooler to get lower temperatures and a quicker cooling of fresh goods. The thing is that the box is quite well insulated and the benefit of the airflow goes only as far as it can reach. And even if the box is quite empty and you would have a benefit of the cold air moving around it won't change the fact that "improved" cooling always comes with more heat in this case. But if we use one of these fan systems to actually improve the airflow on the hot side we not only get better cooling but also a reduce power consumption - something worth considering if you have no backup power generator.... This of course brings us to placement. As I have done the mistake myself you might be tempted to put a 3way cooler onto your seat. Opening it with the back free means the lid always gets stuck on the seat, do it the other way around and you block the airflow. If you do put it on the seat then make sure two things match: 1. The thing is secured properly. 2. The airflow from your aircon is able to reach the hot side of the cooler. Even permanent installations in a camper benefit from a good airflow. Often the fridge or freezer is built into some sort of bench and the airflow behind might be very limited. A simple solution here is to add a vent on top of the bench to allow the hot air to escape. A better one is to use a fan that is powered together with the heating element or compressor and drives the hot air to the outside. How to improve the cold side of the box or fridge? Well, to be honest there is not much that can be done unless you are prepared for some serious work. Depending on compartment size, contents and how full it is a little fan can help to keep the temperatures even but it won't help to get it cooler or reduce the cycling periods for the cooling. The only really working way that I found is to use a "battery" for the storage of the cold. The cooling works by checking the inside temp of the box and if above the set temp the cooling won't stop. This is all well and good while we have a constant supply of power but once we are on batteries it would be great to keep the active time to a minimum. A working solution is to build a container that fits around the cooling element. Smaller types often use an aluminium heatsink, bigger types might come with a compressor and an evaporator. In either case proper sealing is important! Most good models are fully waterproof, meaning even if you would fill them with water they would not leak in other areas than the door. But double check and if in doubt use a bit of silicone to make sure. Ok, but how do we "store" the cold coming from the device? Cold packs ;) These things contain a ready to use mix that holds cold temperatures quite well. Another really good alternative is alcohol or radiator coolant, although the last has limited capabilites in terms of holding capaity for the cold as it is desinged to exchange heat fast rather than to keep it. With a suitable sized and sealed box around the active cooling element we will need longer to actually see any cooling happen (with a warm "battery") but that can be compensated for by good planning or a frozen water bottle. If the cooling element is covered with a box of cooling gel then it has to cool this first before anything happens inside the box. But once it does the pack is already far below the normal temp it would have during normal operation. Remember the inside of the cold pack cools down first before the outside will get cold ;) So once the set temperature is reached the device will shut off. But since the cold pack is far below the set temp it will continue to cool our box until the core is warmer than the set temp. Quick thinkers will now say the benefit is lost as the time required to cool the "battery" down again is much longer than the normal cycle time - and they would be correct. But as we get much colder temps inside the gel box the overall running will still be less compared to normal operation. And since from the second cycle on the gel is only warming up to operating temp of the box it will be much faster than with a warm box. Another benefit might be the ease of cleaning and ice removal. Some peltier driven coolers have big cooling fins or a quite bad design for the heatsink allowing mould to grow where you can't remove it easy. If the box is made from stainless steel and flush with the back wall of the box we won't have that problem anymore. Ok, but how much is good or too much for the size and gel content? You got me there as it is bit tricky. You don't want to loose much usable space for starters and you don't want to wait hours for the gel to cool down if the box was not used. IMHO the size should fit the cooling element with about 20% to spare all around. If stainless steel is not an option than aluminium is the next best choice. Thin sheets can either be be cold formed with a hammer or "brazed" with a good torch and the right rods. Ok, before that route is there anything I should consider or do first? Depends ;) 3-way systems usually use a flame or heating elements to heat an ammoia solution. After years of neglect corrosion can form and reduce the amount of heat transfered into the system and reducing the efficiency this way. It might help to take the heating elements out once a year or so to clean them and the contact areas from any corrosion or dirt build up. With a fixed shedule for this you won't have the problem of never noticing a badly corroded heating element either - and this is the main failure on these systems.... Modifying your camper or making a few mods to your 4WD drawer system is not for the faint of heart and should be done with consideration. The last thing you want to do is rush things to find out it was not necessary. Before cutting holes check if you can't find the room for the fan in a different spot and use ducts to control the airflow - sometimes it is easier to blow air in than to get air out ;) When it comes to creating vents or connections for air to the outside always make sure it is waterproof and insect safe! If you can let the outlet go downwards so water won't run in, for 4WD trailers consider a flap to prevent water from going during a river crossing. Flyscreens will not only prevent insects from coming in but on the inside also prevent dust to go eerywhere - allow to the removal and cleaning! The salts used in these cold packs can be corrosive, so you have to make sure there are no leaks and that there is no steel to come into contact with gel - this includes screw ends hidden in through-holes. If in doubt use a coat of paint but keep it as thin as possible. Even on peltier systems it might be impossible to remove the heatsink without massive surgery on the internals. So before you take it all apart to gain access check if it is far easier to seal around the box opening and possible screw connections using silicone. The cooling battery can be screwed on and sealed with silicone as well as an easy escape route. Although for this to work you need to check if the material of the box allows for a proper bond with the silicone! Some materials just won't allow anything to stick at all, even after sanding them. So do a test first in an area where you would be able to cut the silicone away without causing damage. If you can rip or peel it off the surface you should not try to use a cooling battery screwed to the wall, only use a box that is fully sealed with the cooling element and has a seperate back - one complete unit around the cooling element. I have a 3-way system with a freezer compartment that does the cooling for the fridge too - what can I do? These units either provide good freezing with the fridge temps too low or good fridge cooling with no freezing capabilites - depending on the thermostat used. Our problem is that is next to impossible to add a cooling battery of the normal kind to these systems. The L-shaped freezer box can really only be added with a L-shaped cooling battery from underneath. Only if you don't need any freezing at all you could add a cooling battery to fit into the freezer box shape. In either case the benefit is somehow limited by the way the thermostat is used. If there is no temp control for freezing it should be fine. Warnings... Only peltier driven coolers are free from refrigerants. Every 3-way or compressor system uses refrigerant as evident by more or less piping and heating elements. Never attempt to screw anything into a cooling element containing refrigerant! Even if you think between the channels all will be fine it won't be! The material is just pressed to form the channels and any damage caould mean refrigerant leaking out! Use silicone instead and make sure all surfaces are properly cleaned before applying it, also wait until the silicone is really fully cured before putting any stress on it. As said, these cooling gels can be corrosive, especially if DC voltage is involved. Make sure that everything that is not aluminum or plastic is properly sealed before allowing ongoing contact with cooling gels. Do not attempt any of this if you have to ask yourself what tools you might need or how make a suitable container for the gel. If in doubt check Google on how to work with aluminium or stainless steel if there are not enough Instructables for it. The gel will expand a little bit if it freezes, this no problem in a metal container if you allow for a bit of flex or on the side added strength  - whatever suits you better. Another option is to get a few different cold packs (by the active ingredient) and to do a check in a little container. Freeze it and note whe level cold and warm. Little to no difference means nothing to worry in terms of expansion during freezing.

Topic by Downunder35m