I got a job coming up soon, sharpening the teeth in an all stainless steel bone grinder in a processing plant. The main shaft is about 4in diameter with 12 teeth about 6in tall and about 2 1/2in wide. I was going to weld with stainless rod the worn edges of the teeth and grind them to restore the 90 degree edges. But today the plant manager ask me if i can apply hardsurfacing to the edges. I called the welding supplier in my area and after some research he couldnt find any info for applying hardsurfacing on stainless. Has anyone done this b4? thx
Sheeesh, that's a morbid tool!
Sorry I have never worked on one (actually I am glad I havn't but sorry I cant help)
Is this thing used for feed or will the bone-grindings be used where stainless steel use is perhaps FDA mandated? I seem to recall a carbide-matrix weld rod for oxyacetylene which hard-surfaced with silicon carbide- look in old lnde, UnionCarbide, Oxweld archives- I dont remember much about it and never used the stuff.
regards
d
well, the bones are cooked and the broth is dried into a powder for bouillon cubes and flavoring for gravy in tv dinners, dinty moore stew, ect ect... anyway, i wonder if hardsurfacing arc welding rods will work here........
http://www.thermadyne.com/stdy/literature/product-spec.asp?div=stdy
This page has the addresses of the product specialists for Stoody, a leading seller of hard facing materials. Perhaps that will help.
Bill
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D,
That is one machine I bet you wouldn't have to make the service person lock out before he/she climbs inside. Just the thought of an accidental startup.
John Wright
Also check out some of the Stellite hardfacing products. This link takes you to a product description and to another link to their customer service for more help. Perhaps one of the Deloro alloys would work well on the stainless.
http://stellite.com/en/default.asp?s=41
You might consider brazing a tungsten carbide overlay on top of the teeth. Esab offers a product to accomplish this. You can find it at:
http://www.esabna.com/EUWeb/AS_handbook/596as11_13.htm
Esab's technical service should be able to provide you with more information about your particular application.
Reading about your bone grinder make me think that when our world deteriorates to the point that we have to produce "Soylent Green," we've got just this kind of machinery to do that!
The above sites dont mention applying on stainless. I went to Lincoln site and they have a few hardsurfacing rods that mentions they can be used on stainless. I have a Victor manual spraypowder torch, so now im thinking that is an option after i get the teeth welded and ground. But i need to find a spraypowder that will work on stainless.. But i have a feeling i will end up using Lincoln Wearshield ABR stick rods because the welding supplier here has them in stock.
At my previous job we applied welded hardfacing to stainless without a problem, including Stellite 6 and others.
SA; we are doing hardfacing over ss in my shop using Stellite 6. We're doing it with both the GTAW process and PTAW. Good luck.
Today i was able to get in the plant for a closer inpection of the teeth. I see that hardsurfacing has been applied to the edges of the teeth and now its rounded off. So now it looks like i need to apply hard surfacing to the rounded edges and grind for a sharp corner. Now im thinking TIG welding some hardsurfacing on the edges or stick welding with 3/32 rods. I have a feeling HS stick welding will be porous and crappy looking i think. The alloy originally used is unknown begause the grinder was made in Sweeden. I think this is going to be a trial and error job. :)
Maybe try Hardalloy 120 from McKay.
(just my two cents worth)
Thanks for all your reply's. I just finished the job. I used 3/32 ESAB 308L to repair the scrapes and gouges. I used Lincoln 1/8 Wearshield ABS to restore the hardsurfacing. The job went well with no porosity in the welding.
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SA-200,
Thanks for the update on your project.
John Wright
Use tig and deposit a good buildup of 410 stainless. 410 is an air hardening steel and should work well.
An austenitic like any 300 series will be somewhat"soft" until work hardening occurs. At that point, some dimensional issues will surface.
Email me direct, if you need to.
Good luck
brande