Edit: Australians who need 6mm barrels look inside

[lozz08]

I am going to buy 8mm carbon fiber tube with 1mm wall thickness for a 6mm barrel. Could carbon fiber ever be viable as a barrel? How can I increase the internal diameter by that 0.1-0.4 mm that I want and give it a smooth finish?\


Ok, it turns out that aluminium arrow shafts, size 1714 are perfect for 6mm bb's. They give an internal diameter of 6.035 mm, thats like airsoft tight-bore size. Aluminium is really nice and smooth too. Go to any archery store and ask for single arrows of 1714 size, because most of the time they come in packs of 12 and thats expensive.

[Moonbogg]

Not all carbon fiber tube is meant for holding pressure. A lot of it is structural. As far as sanding it goes, it shreds easily and will fray like crazy. If it were me, I would go with ALUMINUM and never EVER look back (unless a mountain of money landed in my lap, then i'd go titanium).

[lozz08]

well, I'm trying to get some pipe made for me here in aus but it's proving difficult and costly. I wonder how much it would cost, and where the hell you'd get it from, if you wanted to get titanium ones.

[qwerty]

I agree with alluminuim it would be alot cheaper than carbon fibre and easier to cut also the inside oth the tube might be rough and have blowby.

[lozz08]

So here is no way I could use some kind of very light sanding on the inside to smooth it up and widen it a little? Like wet sanding or 1500 grit?

[Moonbogg]

Do you already have a piece that you are stuck with?

[qwerty]

So here is no way I could use some kind of very light sanding on the inside to smooth it up and widen it a little? Like wet sanding or 1500 grit?

Still that would be realy hard to do how would you manage that?
Maybe you could get a rod and wrap the sand paper around it?

[lozz08]

Thats what I was thinking. Or perhaps try to use something like grease with grit in it and slide a rode down it to lightly scrape the sides. Kinda hard to do with what I think will be about 45-60 cm long barrel. There must be a smart way to do this, like submerging the entire thing in a pool of solvent that will dissolve it and remove some wall, or something.

It's not that I'm stuck with a piece, it's that I simply cannot find any suitable metal tube ANYWHERE in this crap land we call Australia

[inonickname]

Carbon fiber is too stable to think of doing something like that with.

Try telescopic tubing from model stores or aluminum tubing from hardware stores.

[spudtyrrant]

(unless a mountain of money landed in my lap, then i'd go titanium).

you don't necessarily need a mountain of money http://cgi.ebay.com/Titanium-tube-tubes ... 6004r17408

[inonickname]

1) That's not rated, it could be seamed.
2) The seller even states it to be a softer temper
3) He admits it's bent
4) It's multiple times more expensive than similar sized aluminum or brass, and that only gets worse as price goes up

[MrCrowley]

Thats what I was thinking. Or perhaps try to use something like grease with grit in it and slide a rode down it to lightly scrape the sides. Kinda hard to do with what I think will be about 45-60 cm long barrel. There must be a smart way to do this, like submerging the entire thing in a pool of solvent that will dissolve it and remove some wall, or something.

It's not that I'm stuck with a piece, it's that I simply cannot find any suitable metal tube ANYWHERE in this crap land we call Australia

I'm in NZ and I found that the metal nozzles from weed-sprayers fit BB's pretty nicely. It has a 6mm inside diameter.

[Brian the brain]

There you go...
Just keep an eye out, you will find something eventually...


And spudtyrrant: I've gotz that Boom-Boom-Pow since about 1984, when my brother and I made our first one...

[Technician1002]

Quick tip, look how to lay carbon fiber and make your own barrel. With a proper form a very smooth inside can be made, or simply lay up a carbon fiber sleeve on a copper or PVC core. It is laid up much like fiberglass. A local plastics and fiberglass outlet near me has the carbon fiber cloth on rolls which is sold by the foot just like fiberglass cloth. It should make a reasonably high pressure barrel that is very light weight.

This video though unrelated to spudding shows how to use the stuff to make an artificial leg.

http://www.youtube.com/watch?v=12jgP_NFDd4

Another video shows the laying of the fiber with the resin for another part.
http://www.youtube.com/watch?v=IAdVO8Rkv6c

[lozz08]

As resourceful as ever tech.

Im gettin the fiber from

here http://www.hobbysupplies.com.au/Carbon%20Tubes.htm

And if they're trustworthy then it's very good stuff.

Something I've been worried about even when thinking of just smoothing the inside of the carbon tube is how to wrap something around a rod seamlessly and evenly to ensure a perfect round shape.

I was thinking, tech, I could try lapping the inside of the carbon like you showed in my other thread, but as above, don't know how I could do it perfectly, or find a rod of the right diameter to slide down and cause the abrasion.