Alushield or similar... near to Brighton?

[Pedroski]

Hi Folks. I've been reading your forum here lots and lots over the past few weeks - a proper lurker! And am wondering.....can anyone recommend a source for Alushield or similar, in my local area. I've gone through the gas suppliers list, and made a couple of calls, but I don't want to go down the route of expensive rental for occasional use. Looking really, I suppose, for a size X, possible Y, cylinder for starters. Any recommendations?

Thanks in advance

Pete

 

[hotrodder]

Alushield is BOCs name for argon/helium mixes, BOC = rental and helium = more expensive. Unless you need the helium (thick sections and/or underpowered machine) the pure argon will cover you for welding aluminium with MIG, everything with TIG and be cheapier and easier to source

 

[Pedroski]

Cheers Hotrodder. I'm after something with helium as I actually want to DC weld on fairly thick section aluminium subframe on a motorbike, and also other relatively thick sections. In the past, I've done stick welding and gas welding on aluminium, and I know for TIG that ac is probably the easiest route. But I'm up for a challenge.

Wonder if it's possible to just use flux, as if gas welding, and use the torch at a somewhat shallower angle to give wider arc spread (kind of like flame spread when gas welding)?

 

[backpurge]

If you're wanting to DC weld ally you will probabbly need to use pure helium and not alushield

 

[hotrodder]

Either way (welding grade He or Ar/He mix) i doubt you'll find a rent free source as neither are in common enough use to make it profitable

DCEN with He is a much hotter process, i can't see something like a motorbike subframe ending well personally due to it's lack of mass, even if you're very quick. Might be able to find a compromise with an Ar/He mix but i suspect alushield light will be little if any improvement over pure argon (i.e. absolutly no sign of a weld pool as we know it so you have to use 'the force' and probably end up with a mess of oxide inclusions as a best case scenario).

Oxy fuel flux... heard of it being used on the back of a joint (where the arc can't 'clean') but i suspect if exposed to the arc you'll have a big mess on your hands (trashed tungsten, flux vaporised due to the heat from the arc) which you probably won't be able to see due to the orange sodium glare. If you were to try it i'd be fluxing the filler wire lightly and the back of the joint only. I don't think it'll work well (if it all) but if you've got a TIG and some argon nothing to lose except a tungsten tip and some time. Might be an improvement over DCEN and Ar (couldn;t be much worse) but obviously the initial 'puddle' will be similar to trying to use oxyfuel without flux i.e. a dull wrinkly oxide skin just before it collapses as the ally underneath is already molten. The bike subframe really wants subbing out to someone with suitable AC kit though imo- probably be cheaper than buying/renting a cylinder of helium, definately be safer than trying to work around a lack of the correct tools for the (structural) job

 

[Pedroski]

Thanks for the advice I've now spoken to a bloke at a precision metal fabrication place near me who will do it for £20 cash. Can't get fairer than that.
Cheers again,
Pete