Welding Tips and Tricks

I've got some stainless to weld shortly that is going to be a pain to try to backpurge. I've heard about using solar flux but have never tried it. How well does it work? Which one do you guys use?

Solar Flux B is what is designated for Stainless. Easy to apply, provides great protection. Difficult as S*@( to remove. It turns into a very hard, glass like slag deposit on the backside. It doesn't "wash off", just so you know. Cheapest I have found it is weldingsupply.com for the 1lb can.

+ hard to remove

The glass like deposit is hard to remove, but it does work well though to prevent the sugaring on the back side of welds. Any 'non activated' SolarFlux that's left does wash off with plain water.

I use it fairly regularly on 304/316 car exhaust pipe work, so I'm not bothered by the residue it leaves on the inside as it's quite smooth, so (unlike the sugaring 'lumps') it poses little to no problem for the gas flow and kicking up unwanted turbulence inside the exhaust. Would be a different story for sanitary welds..

I still tend to back-purge in many cases, but for some applications I do grab some SolarFlux and it can be a big help.

I like how a little goes a long way.. I normally use ony a small cup and use a little 99.9% methanol to get it into a liquid form and then use a small brush to coat the seams/joins and small area around them. Doesn't need much.. Then just let it dry to a light grey 'clay' like colour and you're set. It can be left in that state for quite some time so you can prep more tacked-up pieces for later full welding.

And it's really a flux as you can also use it (whan applied to both sides of a weld) for oxy-acetylene welding stainless...

Bye, Arno.

I've used Solar B flux with pretty good results.

I'll very likely be using it again shortly on a motorcycle exhaust that would prove a real pain to purge.

The one thing I will add in addition to Arno's great wrap up is that Solar B still demands good technique and isn't great for stainless learners. When I first used it I was hanging around too long and running too hot and the result was that the flux 'blew out' on the inside of the pipe, meaning normal nasty sugaring then ensued.

If you are a competent stainless welder then I feel Solar B is a pretty good alternative.


Kym

Thanks for the info.