Tool rest problems...

[Gunslinger]

Ok, wood AND metal workers. I purchased a toolrest and did not think about the post length. So far I have 1) welded an extension on with my stick welded - the weld broke :BangHead:,
2) welded the extension on with my wire welder – the weld broke :BangHead: :BangHead:,
3) cut a bevel and indents into both and tried JB Weld (twice) – both times I could break it by hand :BangHead::BangHead::BangHead:.
I thought the "third time" was suppose to be a charm.
The "joint" will always be inside the banjo holder so there is only downward pressure.
Any way to join cast iron and steel? Brazing rod?
Thanks,
Mike

 

[Gotcha6]

Cast iron is best welded using nickel welding rods ($$$). Alternative joining would be brazing. Butt welding a shaft like that is tricky because the banjo is applying pressure to both halves of the joined piece. If they aren't in perfect alignment it creates an axial stress causing the weld to break. Difficult to execute because the heat from the welding will cause the piece to draw one way or the other. If you had a way to drill out the ends of the shafts & insert a metal dowel with set screws or roll pins - even tapping and using a threaded rod, it would be better.

 

[scsmith42]

Mike, I've welded up some tool posts for NCTurner, and I used a TIG with a furnace brazing rod. No problems reported thus far.

I prefer the tig over a torch for brazing because I can concentrate the heat better and minimize distortion.

Nickle rod is another option. I have also welded cast iron with stainless steel rod in a stick welder. I've used nickle rod both in stick welding and with a TIG welder (wire brush the flux off of the nickle rod and it works fine).

If you preheat the larger pieces, you should be able to stick weld them. However, I'd probably still lean towards brazing.

If you're near Raleigh, I'll be glad to break out the tig and braze them for you.

Scott

 

[dlrion]

+ 1 for gotcha's way

The simplest way might be just drilling it out, and then bolting it. If you did it right you could even tap the upper side, thus preventing the need for a nut.

Dan

 

[Gunslinger]

Thanks for your input guys.
Scott, if I were near Raleigh I would take you up on your offer and it is appreciated.
I have a friend who owns an automotive repair shop so I am sure he has the torches (I already have brazing rod).
If the brazing doesn’t work I will tap the upper post and install a bolt through the lower addition.
Thanks again,
Mike