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Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 12:25 am
by fredygump
I am working on fixing/ improving a tool I use for my job.

The tool is for installing and removing pipe fittings used on underground storage tanks (fill and vapor recovery adapters). It's mostly just a piece of 5" schedule 40 pipe with some notches cut into it, but don't be deceived...it costs $500.

The edges of these notches are getting worn, and I'd like to build them back up with something that is harder than regular mild steel. I need the edges of the tool stay square.

This tool does see a bit of abuse. Often times I end up using a 24" pipe wrench with a 48" cheater bar to loosen these adapters. When that happens, something has got to give, and recently this tool has been losing... The worst is when the tool slips past the tabs it is supposed to be pushing against (because of wear...), and I spend 15min trying to pry the tool off.


What would you do? Is a true hard facing the way to go? Or is there a filler material that is inbetween a mild steel and a hard facing?

I can do either TIG or stick welding. Being that the surfaces are small, I figured TIG is the way to go. But I'm not having much luck finding a hard facing filler for TIG. However, I have seen a couple mentions of using stick electrodes for TIG, first knocking off the flux?


(The other part of the problem is that the tool has some flex. I plan to add a reinforcing ring that goes around the outside of the tool to prevent those notches from spreading. The plan is to use a slice of 6" schedule 80 pipe, with a 13ga (3/32") shim to fill the gap between the two sizes. It's almost a perfect fit--it'll leave just .009" between the outer ring and the tool.)

Re: Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 2:18 am
by Poland308
Hard facing will only reduce wear on the surface. It won’t change the strength of the base material your working with.

Re: Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 3:14 am
by fredygump
Poland308 wrote:Hard facing will only reduce wear on the surface. It won’t change the strength of the base material your working with.

Huh?? Who said I am trying to increase the strength of the base material?

I think a carbide saw blade is a pretty obvious example of something hard attached to something softer. It is a proven principle.

The question is HOW to do it.

Re: Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 4:33 am
by weldin mike 27
https://www.esabna.com/euweb/as_handbook/596as11_20.htm

Esab seem to have a number of items capable of steel on steel protection. However, the heat of the welding process will likely damage the steel of your special tool.

Mick

Re: Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 8:43 am
by LtBadd
Lincoln, scroll down for their TIG selections

Re: Fixing a tool: hard facing or ???

Posted: Sat Feb 23, 2019 3:15 pm
by Poland308
I was referring to what mike mentions. Sch 40 5 inch has a wall thickness around.25. If your welding on the edge of the notches to harden the face you will be softening the rest of the tab. Another option would be to have the tool hardened entirely before you use it. There are companies that specialize in these heat treatments. They can just harden the tooth area so that you maintain the malabilty of the upper portion.