Question About ABS

CHF64 · Sat Mar 25, 2006 7:18 am

Hi, I am a newbie to making spudcannons. I was looking around home depot today and I wanted to know if using the black ABS plastic they sell there is ok. If it is what sort of adhesive do you use? Just the normal ABS stuff that they sell there. I don't know too much about plumbing or piping and I tried searching but didn't find too much. Any advice would be appreciated.

dragon finder · Sat Mar 25, 2006 8:57 am

abs is not a good material for spud guns because it is more brittle that pvc. If you were going to use it use it only for the barrel. I have seen abs guns with success but I have heard bad things about it be in used.

bjbrokaw · Sat Mar 25, 2006 9:09 am

Ya, I have my 1st cannon (completly out of ABS) Blow up in my hands. It didnt shatter into hundreds of pieces but ripped into 2 big chunks but the sound (it was shoulder held cannon) left me deaf for 2 days out of my right ear.

)DEMON( · Sat Mar 25, 2006 10:08 am

you shouldnt have tested it on your shoulder

PaRaSiTe · Sat Mar 25, 2006 12:29 pm

Ouch lol. But how else would you test a shoulder mounted one to full effect?

Shrimphead · Sat Mar 25, 2006 12:35 pm

ABS is less brittle than pvc, that's why when bjbrokaw's broke it didn't shatter. It just isn't pressure rated like pvc. An Abs failure is safer than a pvc one, but pvc is less likely to happen. Also, abs can be used for a combustion (including the chamber), but that is a little questionable because some have still failed.

Bjbrokaw- Was you cannon that exploded pneumatic or combustion?

CHF64- What pipe you use just depends on the gun your making. If you want a combustion you can use Abs, but pressure rated pvc (If it says nsf-pw XXX pressure, then it's rated) is safer. If you want to make a pneumatic DON'T use abs. And don't try to solvent weld abs pipe to pvc even if the glue says it works for both, they won't hold together and your barrel will go flying.l

saladtossser · Sat Mar 25, 2006 2:09 pm

imagin as if pvc is a glass bottle, and abs is a plastic bottle

a huge truck runs over both, what happens?

also, some good news about abs, abs cement does indeed melt the abs plastic, where as in order to do the same with pvc, you need primer and cement.

if you must use abs and pvc together, join them with threads.

boilingleadbath · Sat Mar 25, 2006 2:51 pm

Most ABS pipe you'll find will be cellular core, that is, the wall of the pipe is composed mostly of foam. Because of this, it'll fail at lower pressures than pressure rated PVC.

Although pressure rated ABS pipe does exist, it is expensive and extremely rare. As an interesting point, it's the only plastic pipe actually rated for pressurized gases, because it's mode of failure doesn't produce shrapnel.

CHF64 · Sat Mar 25, 2006 4:20 pm

Thanks for all the input. Sorry I forgot to put what my intended design was. I was going to make a simple combustion gun with the bbq lighter and use starter fluid for it. From what I've seen abs seems like a better choice for beginners because ripping is much better than shattering in my opinion anyway. Also a lower pressure failure seems a little safer to me as well because higher pressure plus chance of lots of shrapnel seems like a more dangerous situation. Once I know what I am doing i'll start looking for higher pressure rated PVC. Do most people get their supplies from home depot or Lowes or a similar hardware store? Or is it better to order it online?

schmanman · Sat Mar 25, 2006 4:22 pm

NO! I would hate to loose a fellow spud gunner. Anyway its better to be safe than sorry.go with schedule 40 pipe and fittings at the least.I wouldnt risk it.

SteamRoller · Sat Mar 25, 2006 4:59 pm

Not that i'm advocating it, but my first combustion was all ABS. I have never had any problems with it, it's been in use for about a year. DO NOT use it for a pneumatic though.

boilingleadbath · Sat Mar 25, 2006 6:51 pm

To tell you the truth, I'v never heard of a pipe failure with pressure rated PVC. True, there was one case where someone solvent welded inproperly and the fittings flew off, but that occured with a pneumatic at 120 psi or so, and the damage would not have been reduced by using ABS.

So worrying, because if you don't do anything stupid (O2-C2H2, for instance), nsf-pw PVC won't fail.

And sch 40 is just a wall thickness; cellular core can be (and normaly is) sch 40.

saladtossser · Sat Mar 25, 2006 7:01 pm

abs is great in minus 0 degrees

also http://tomacorp.com/ballistics/ABSvsPVC.html

http://www.monarchplastic.com/QualityCo ... ontrol.htm

schmanman · Sat Mar 25, 2006 7:59 pm

never mind,i was thinking about pnumatics. I dont know much about combustionguns . I am a pnumatic cannon person

Shrimphead · Sun Mar 26, 2006 12:54 am

Pressure rated pvc will never fail in a combustion unless you are using oxygen and acetylene (which would technically make it a hybrid) or some other high-powered fuel. I would suggest going with pvc just because the abs has a possibility of failing which would cost you the price of a new gun.