SpudFiles

Hey everybody,

This question addresses everybody, but I especially want the feedback of people who make BBMG's and other bb guns.

I have 1/4 inch brake line, and want to use it as the barrel in a pellet/ piston gun, but find that the factory fitting on the end would not reach back far enough into a T to be effective for a piston, it would hover in the middle of the T, but I want to extend into a nipple behind it.

So I was wondering how YOU would attach 1/4 inch brake line to a 1/2 inch galvanized (threaded) T.

Any sort of epoxy is out, even if I had it, I would not trust it with high pressures, I was thinking more along the lines of a drilled out end cap or threaded plug, and how I could secure it into that.

Hole drilled through this...


so brakeline will go through this...

you should drill a hole so the brake line fits very snugly inside.
and yes, you should use metal epoxy, its fine under pressure.
thats the only way you could do it without welding.

What about like JB weld or something, would that work? because I do not have much money with which to buy special adhesives.

sputnick wrote:What about like JB weld or something, would that work? because I do not have much money with which to buy special adhesives.

That's fine. I'd recommend to leave it to dry for a week before using. I've got best results waiting a week. It says 24hours, but I reckon it's prone to stress fractures a lot more if you only leave it for 24hours.

How about a compression fitting? What I did on my bb gun is I drilled out the stop on a 1/4" compression fitting and slid the brakeline through that into the tee, from the inside so the factory made lip on the end could be used as the sealing area. I found a 1/4" compression fitting with 1/2" npt threads, you could always use an adaptor.

Depending on the pressure, epoxy is probably safe.

But you could also find a pipe/tube slightly larger than the brakeline and have a short section of this on the inside of the t with a hole drilled slightly smaller than it, so that the force of the piston is being applied to the steel fittings. And then sleeve the brakeline inside this or position it just outside depending on the sizes.

You should be able to use JB weld on it: I used it several times both to construct and repair leaks in my pneumatic. It should hold up, unless you intend to use some really high pressure. The highest I can personally recommend it for is about 300 psi: that's the highest pressure I've used it at.