Question About ABS

[DoctorJesus]

Has anyone built an abs cannon that uses propane? I was thinking about adding a metered system to my combustion cannon, but was worried that it might cause a failure.

[Pete Zaria]

Ive built 4 cannons, all ABS. My current one has a 4"x2ft combustion chamber, 1.5" barrel. I have a propane meter on it, which works just fine. Personally I think it's impossible to "blow up" an ABS cannon with propane. If you put that much propane in there, there wouldn't be enough oxygen to combust it, and it wouldn't fire at all.

However, I did blow up one ABS cannon. But I put nitrous oxide and propane in it at the same time, so I was asking for it. (I knew that'd blow it up, it was an old cannon and wanted to get rid of it).

I prefer ABS. If it DOES blow up, it'll crack clean instead of making shrapnel like PVC would.

Peace,
Pete Zaria.

[spudshot]

ABS is just fine for combustions, propane or otherwise (well except when you add oxidizers or use acetylene) but for pneumatics, go with PVC or metal

[CS]

ABS is a iffy material. Celluar core ABS is two sheets of thin ABS plastic composing both the outer and inner walls. Between these sheets there is a hard foam looking material, which obviously would not be able to retain pressure if it by itself were presented with pressure from a combustion.

But think about it, I would guess that the thickness of these ABS sheets is about as thick as a soda bottle. Meanwhile people charge soda bottles to triple digits in PSI. The composition between the two plastics may play a role, but not to a extremity I would think.

We know sch 40 is stronger, so why not use it? You can try to determine if ABS is "safe enough", but why not be even safer and use pressure rated PVC? I have a some ABS combustions, none of which have failed or shown any sign of weaking.

ABS belive it or not has a upside. As you stated before you would like to use starting fuel. If im not mis informed ingredents in this fuel and others can "eat" at the PVC and lessen its capabiltys as pressure goes. Hence the use of it in ventage systems because it "resistant" properites to chemicals. Not sure about cost, but that might also be a factor over other plastics.

[schmanman]

It's a little off topic, but ,I dont think I've ever heared of a simple regular combustion made out of steel.

[spudshot]

i've made several out of old pipe fittings i have laying around, simple, fun, and easy to put together

[SpudStuff]

i have propane on My Cannon and it only has positive effects