2 replies to this topic

[blakmoose1234]

I'm planning on working on a homemade air-powered nerf gun, and learning from my past guns that I've made, I am determined to make sure that this one does not leak like an ass. So anyway, on the previous two I have worked on (NerfHaven's Cutlass and Ball Valve guns) I did not use pvc glue primer and I did not give the pvc glue time to dry. Also, I used hot glue for the tubeless tire valve and my Cutlass's threadings leaked really badly. These are all mistakes that I know were stupid, but at the time I just wanted to jury-rig them to work so I could flex nuts with my friends. This time though, I'm willing to do a half-decent job (another year wiser I hope), and I have a few questions about the basic construction of a pvc nerf gun:

1. What is plumber's goop?
2. What's the best way to use pvc glue?
3. In case I decide to stick two endcaps together, how do I solvent weld? And what is solvent welding?
4. How do I cut a nice chunk out of the pvc for a breech without cutting the entire length of pvc into two halves?
5. How should a tubeless tire valve go on?
6. Are 12gram or 12 oz Co2 tanks a good Idea? Would Co2 freeze the glue, leak, or make the gun brittle?
7. Where could I get a holdable air pump that is lighter than a tire/bike tire pump and that I could mount on the foregrip?
8. Is the simple o-ring pull valve in the homemades aisle on this website a good alternative to a solenoid?
9. Are all these questions really stupid?
10. Any thing else I should keep in mind when I jump into it on sunday?

I haven't "Searched" with the search button on this site, but I have kept track of all the homemades' topics all the way back to page 7, and correct me if I'm wrong, there aren't that many write-ups that specifically answer all of these questions. I have though, kept an eye on some of the homemade ideas. Some of these questions I threw in although I have seen them mentioned though. Talio, please don't smite me.

[sam]

1. a strong adhesive, lots of people swear by it, I won't say more becasue I have never used it.
2. Put PVC primer on it then the adhesive, again I've never used it, so someone else should back this up
4. Use a dremel
6. CO2 will make the gun pretty brittle, look at boltsniper's semi-auto technology demostrator
7. Bike stores, hardware stores, just look around
8. It functions similar to an AT2K valve, it won't open air as fast as a solenoid, but you should be able to get good ranges with it.
9. A lot of these questions have been talked about, use the search next time, it proabably would have answered alot of your questions.

[CaptainSlug]

1. A sealant/adhesive
2. You spread a thin layer of purple primer on the PVC to roughen the surface a bit, then use the gooey PVC adhesive sparingly but spread around evenly and then shove the parts together using long clamps and maybe even a wood block and hammer. PVC cement and primer both smell terrible and produce alot of fumes so make sure to use them only outside.
3. Solvent welding is using a specifically formulated adhesive that will chemically bond the two like pieces together. These will produce the most mechanically durable bonds possible out of any adhesive and generally have lower viscosity and therefore can fill in more gaps. They are however made for only a specific family of materials and will only work in that group of plastics.
4. And rotary tool using a toothed plastics bit. Abrasive bits suck at cutting plastics.
5. Schrader valves aren't very usable and will be difficult to seal. You should consider using a check valve and a tube-to-stem (5/16") adapter instead
6. Co2 is not safe to use with plastics for prolonged periods of time. Most plastics cannot handle low temperatures or thermal shock and will shatter. Co2 tanks are also only designed to contain liquid Co2 and won't be usable as high pressure air containers.
7. Search function or any bike shop
8. Solenoid valves are quite expensive so almost anything would be a preferable alternative
9. Yes, and most easily answered by searching here and other places