welding fixture locator materials 1

[wallycutler]

I am designing a welding fixture. We will be MIG welding low carbon steel conveyor frames. What material should I use for locating surfaces. It seems I remember back a long time ago using copper, or some form of copper, as locators to minimize weld splatter buildup.

 

[steveh]

That probably depends on how heavily the fixtures will be used. Copper is OK for low volume fixtures in which wear and tear is not a big factor.
For lots of use (and abuse) I prefer Ampco. It's one form of aluminum bronze (85% Cu, 15% Al). The material has very low resistivity and is easy to clean - spatter sticks very little.
On the down side, it is in some ways harder to machine than copper. Take special care when drilling and reaming since, like copper, it will tend to 'grab'.

Steve