SpudFiles

Are those solder that can be used on "STEEL" safe on high pressures like 500-700psi?

I wouldn't trust household plumbing solder on anything using more than 500psi even if it has a silver content. You need to get high silver brazing wire and use the proper flux for it. I work in the HVAC industry and the stuff I use requires a oxy/acetylene torch to properly braze fittings. That stuff I trust that high.

Nope. Normal solder doesn't stick to steel in the same way as copper, particuarly if it's stainless steel.

However, a good solder joint on copper will usually hold past the burst pressure of the pipe itself.

High silver HVAC stuff will stick to stainless but you have to be careful. If you decide this route I can get some info for you.

http://www.harrisproductsgroup.com/

Oops, totally misread the question, sorry. Usually a good solder or weld joint will las past the pipe itself, because a smaller amount of force is being exerted on it. this may be different for steel, as copper is quite soft, but I imagine I will be fine at 700psi

I would definately not recomend household solder for this, instead, as recomended try brazing. It is similar just used higher temperatures, the brazing rods and wires are also fairly expensive(here i pay 30bucks for a foot or so of wire) so it might be cheeper to thread(or otherwise connect) your cannon parts together, that simply depends on the amount of joints you ave to make. Also you have to use the right flux, overall the process requires a bit of practise.

And oen more thing, i have made this mistake and it was very annoying, remember that not everything can withstand 700°C(or even 500). i have fried my fill valve and replacing it was a pretty big pain, and very time consuming. Also certain thin walled pipes start to oxidize("rust") when they are heated eanoth and then they just crumble.

john bunsenburner wrote:oxidize("rust")

One word: Carburising.

A carburising flame is just an excess of fuel or lack of oxygen.

Braze it, solder will give you a hell of a time. If you want simplicity and ease then simply use threaded fittings.

Threaded fittings it is. Thanks guys!