rod help plus whats best for steel tank

[general--lee]

hi is a 5% silicone rod pretty much ok for all ally?

or is that just for non cast and 10% for cast?


i understand i need 5-10% mag rods for strong ally stuff?

tig brazing rods are these ok .....
http://cgi.ebay.co.uk/One-Kilo-Sili...trkparms=65:12|66:2|39:1|72:1683|293:1|294:50

i have some gas brazing rods but they are no good?

is tig brazing better for a petrol tank then tig welding (in steel)


thanks ken

 

[hotrodder]

Aluminium filler selection chart, a lot of the time it's a trade off between different characteristics. 4043 (5% silicon) will work for most things including many castings, not a good choice for magnesium rich alloys (5xxx series)

The silicon based fillers are generally the easiest to weld with (wet out well, more crack resistant) but they are relatively brittle, most noticable in fillet welds or butt welds that will be planished. Strength is less of an issue as the wekaest part of an aluminium weld will generally be the area next to the weld that was annealed during welding

Those brazing rods appear to be OK for TIG, the designation for siliconcopper / siliconbronze filler would be CuSi3. General purpose gas brazing filler contains loads of zinc and so are no good for TIG- the zinc vaporises and just results in a right mess

Fabricating a petrol tank... butt joints i would always weld, flanged joints add strength and stiffness to a tank and lend themselves to brazing well