Poured Concrete Hybrid Chambers

[spudman029]

You are exposing the concrete to sudden pressure spikes

The concrete will be pour around a steel chamber so it won't be directly exposed to the pressure spike...I don't think it will be a problem...

If you were going to use a steel chamber from the beginning...what's the point of pouring the concrete?

[SpudFarm]

wire and rebar are just to keep its shape in case of busting... like to keep a wall from falling over if it cracks.

It also gives concrete better tensile strength. Concrete is strong under compression so strong in fact they were talking of making concrete submarines for the military. I don't know if they ever did (if they did I'm sure we don't know about it) But I've read articles of people making sail boat hulls from the stuff as well.

Steel reinforces the concrete weakness. Correct me if I'm wrong but concrete has a fairly low tensile strength and steel has a very high tensile strength. That is why they reinforce bridges and most concrete structures with re-bar. Scott was right in a way it does help to hold things together but it does a bit more then that.

On a separate note... I think it was Poland Spud that brought up a similar idea only using lead...

spudfarm

[DYI]

If you were going to use a steel chamber from the beginning...what's the point of pouring the concrete?

To allow the steel to hold more pressure...

I don't know for sure if I'm actually going to try the whole "50x concrete/steel hybrid" thing, but I am going to fix my old 1.5" bore oxy/MAPP gun so that it can be used as a handheld 4x launcher. (which, in comparison to my current project, is roughly equivalent to a particularly poor peashooter)

[Jared Haehnel]

Yup, sorry about that Spudfarm...to many names that have "spud" in it....

[SpudFarm]

wow DYI think of the recoil of a 1.5" bore hybrid

[DYI]

Well, I've suddenly lost my interest in using concrete - today I was building a bipod for the SCTBDC (didn't work too well). The bipod fell toward me, and I had to let go of the launcher to get out of the way. The concrete breach fell 4' to the road, and shattered into 3 pieces, as well as breaking the ABS fittings inside.

So now, instead of shooting today, I'll be fumigating myself with fiberglass resin trying to put together a solid breach for tomorrow.

[Jared Haehnel]

.....Bad day for DYI....

Its good thing you weren't hurt

Fumigating... huh? I can just hear the brain cells in your head begin to scream....

[biged]

Avoid using concrete as a barrel. The reason you do not see concrete barrels used throughout history is because the bronze, iron and steel barrels survived multiple use.

If need be, inspect it after EVERY USE. Pick it up and shake it. Listen for loose fragments. Each shock wave will effect it like a jack-hammer.

Be safe...

///ed///

[DYI]

I've already decided against using concrete. It just isn't worth the danger, and it breaks too easily. It could be cracked, and you may not even notice it until it blows up in your face.

As for what I will use... I don't really know. Fiberglass resin is $18/946mL. If I were to cast the chamber of my oxy/MAPP gun in it, I'd need 4 cans, which comes out to over $80 when you add taxes.

So, it may be quite a while until you see my lightweight, handheld 1.5" bore hybrid.

[SpudFarm]

if weight is no problem i would use lead.. if can take loads of shockwaves and not take damage.

that is why people think of making a DDT gun out of steel pipe with lead inside.
and lead is cheap

[brogdenlaxmiddie]

THANK YOU! As I was reading out the whole topic before speaking, all I could think of, was that this was a bad idea. I asked my father about your situation as well, seeing that he had concrete experience for a life-time and he said " The disadvantage of weight versus strength does not balance. You'd be better off welding rebar together to form something like a tube with multiple layers of rebar. However, that would only make sense if you had say a large welding machine." With all that said, I feel that you made the right decision against using concrete. So, in the end, just use high-pressure steel.
-Tedder

[starman]

I've already decided against using concrete. It just isn't worth the danger, and it breaks too easily. It could be cracked, and you may not even notice it until it blows up in your face.

As for what I will use... I don't really know. Fiberglass resin is $18/946mL. If I were to cast the chamber of my oxy/MAPP gun in it, I'd need 4 cans, which comes out to over $80 when you add taxes.

So, it may be quite a while until you see my lightweight, handheld 1.5" bore hybrid.

Have you thought about a carbon fiber wrap? Extremely strong and light weight.

[brogdenlaxmiddie]

Did you know that in the CCR-Aero They used carbon fibre to build part of the engine block? ( For those of you whom don't know, The CCR Aero is that current world's fastest production car) So, Yes starman, Carbon fibre is extreamly strong, however expensive.

[ammosmoke]

Actually, the Aero might have been outdone by the Barbarus TKR, but heck, I think the Aero looks better. Do you mean this?

http://www.shelbysupercars.com/

EDIT: And errr the block is solid aluminum. And CCR is the car the Koeniseigg made, not the company that made the Aero. Unless I am mistaken... ?