Instructions on how to modify a spiderman webslinger into a handheld flamethower. Disclaimer: I havent had any problems with this design and I have never been burned by it, however it still is dangerouse and I take no responsibility for anyone who attempts to build this.
Step 1: Parts
The parts list is pretty simple and cheap. Everything together should cost less then 40$
1. Spiderman webslinger toy with three attatchments( Waterbottle, dart shooter, and silly string) Bought on e-bay for 13.19
2. Sturdy clear 1/4" vinyl hose. About 2 feet length.
3. Devcon- all purpose adhesive and vinyl mender.
4. Computer keyboard duster.
5. Pouch attatchable to belt, or make one using duct tape( I used an infared thermometer pouch by cutting it down the side, taping it, and adding some velcro) used to hold the can of air.
6. Benzomatic handheld blow torch. Bought on e-bay or at home depot.
7. Rollerblading wrist guard.
8. Zip strips
11. Drill with 1/4" drill bit
Step 2: Make a Pouch to Hold Can of Air
Using duct tape and whatever other materials are avaiable, fashion a pouch that can hold a computer keyboard duster can and attatch to a belt. The simplest way to do this is to just tape around the can twice and use the tape hanging off to tape around a belt. However, what I did was use a belt pouch for an infrared thermometer cut it down the sides so it could hold the can, duct taped the bottom, and sewed 2 pieces of velcro around the top to hold it in.
Step 3: Make the Ignition Source
Using the Benzomatic handheld blow torch, the zip strips, scissors, and the wrist guard create a ignition source for the handheld flamethrower.
1. Unscrew all the screws on the side of thlow torch and open it carefully so none of the parts fall out.
2. Remove the metal safety on the trigger, and close the torch back up. This will allow for easier one handed operation.
3. Cut the handguard in half as shown in the picture. Cut away part of it that goes over the palm side of your hands and wrists. I left the circle for the thumb still on so it will fit more securely.
4. Using at least 3 zip-strips attatch the torch to the wrist guard. Put the strips through holes you punch with the scissors on either side of the plastic protector piece.
Step 4: Modify the Water Tank
The spiderman webslinger waterbottle attatchment has a very cheap and ineffective pumping mechanism. This would not be good for a design that uses pressure to keep the flaming stream of liquid away from your body. Using the saw, and the devcon all purpose weldit modify the plastic bottle so it will never need to be pumped again.
1. Unscrew and remove the gray plastic halves on the back of the bottle.
2. Remove the pump and pump handle.
3. (Optional) Remove the white one way pressure valve on the inside of the tank. This step is optional because you do not need to remove the valve, but it increases the capacity of the tank.
4 (Optional) If you removed the pressure valve then you will need to find a sturdy piece of plastic and glue it onto the inside of the blue end cap. Cover boths sides liberally with the multipurpose weldit wait a few hours and then coat it again. Wait 24 hours after the second coating for the glue to completely harden. If you did not seal the end cap well enough when you pressurize it, the cap will blow out spraying you with the contents of the tank.
5. (Optional) Trim off about 1" of the gray end piece to save room. Warning: Make sure to leave the 2 screw holders and metal bar reinforcement in place.
6. Firmly place the end cap back on the bottle and screw the two gray halves on top of it securing it in place.
Step 5: Make a Hose for Pressure
I thought of using canned air to pressurize the tank when I was thinking about what flammable substance I would fill it with. The included pump with the toy would require 10-15 pumps to get the tank just slightly pressurized and that pressure would quickly run out. At first I thought a solution to this problem would to be to mount a battery operated pump on top of the tank, but instead I realized a simpler solution would just be to add a can of air.
1. Cut an appropriate length of 1/4" hose that will reach from the can of air on your belt to the tank on your wrist.
2. Unscrew the cap on the top of the plastic bottle and remove it along with the string meant to keep it attatched to the bottle. Cut the string and discard.
3. Remove the rubber sealer from the rim, and drill a 1/4" hole in the plastic cap. Using lots of multipurpose weldit seal the inside and outside of the cap.
4. Wait for the glue to dry and then replace the rubber sealer around the hose.
5. For the other end of the hose make an attatchment that can be pushed down on the top of the can of air to pressurize the tank. The simplest way to do this is to remove the plastic top piece with trigger from the can and cut away everything but the circular verticle piece that directly attatches to the valve on the can.
6. Once you have the plastic piece (which should be about an inch long) sand the outside of it to make it rough. Cover the outsided sanded area and the inside of the hose with the weldit glue and wait 1 min for the glue to get tacky. Once the glue is tacky press the plastic piece into the hose as far as it will go and wait 24 hours or until it is completely dry.
Step 6: Assemble All the Pieces
Put all the pieces together and get ready to fill the tank with flammable liquid.
1. Put the can of air on your belt wherever it feels the most comfortable with the length of hose you used.
2. Fill the bottle 3/4th full with water for a test run.
3. Screw the hose onto the bottle by holding cap in your hand and either rotating the bottle underneath it or carefully spinning the cap down onto the bottle until it is secure.
4. Strap the handheld torch to the underside of your wrist (when holding arm out palm upwards)
5. Connect the plastic bottle to the holder, lock it in, and strap the holder to your wrist.
6. Go to a place you can shoot water, take the open end of the hose and press it down onto the top of the canned air for a second. You shouldent hold it down for more then a second because too much pressure might build up and it could pop off, however after you press it down for a second you still might need to keep your hand on it so it dosent pop off.
7. Press down on the 2 finger trigger, water should stream out about 14 feet.
8. (Works best in dark place where it is easy to see the jet flame from the torch)Light and lock the torch. Adjust it to the maxium flame setting. Press back down on hose to recharge the bottle. Press down with your 2 fingers to shoot out another stream of water, only this time check to make sure it is passing through the flame. If the water passes through the flame it means that it will ignite when you are using a flammable liquid, if not you need to adjust the blow torch on your wrist so the stream of liquid will pass through it.
Step 7: Flammable Liquids to Use
As I have not yet found the ideal liquid for this I did not include any photos of me actually using it becuase it wouldent show it at its full potential. I saw a video online where some kids used bmw windshield washer fluid concentrate and a water gun to make a flamethrower which worked fairly well. I have also seen some videos where a guy uses dentured alchol. The ideal liquid would have a low flashpoint, wouldent dissolve any of the glue used on the parts, and can be ignited in a stream. Im waitting for a shipment of windshield washer concentrate to test, although if it works it would be kind of pricy for a permament solution.